Frog Dissertation

Objective

Recreate a Frog in CG with photo-realistic look, which includes anatomy, behaviour,

movements and integrate seamlessly into live action footage.

Team Members

Shamili (Modeling & Texturing)

Sachin shekhar (Rigging & Animation)

Adithya sirivella (Rigging & Animation)

Naga kartheek (Match move)

Suresh kumar (Lighting & Compositing)

Content Details

1. History of Frog

Origin of word

Frog – In different languages

Taxonomy

Etymology

Evolution

Entire history

Mythological Status

Social Role

Role in Stories

2. Different types & breeds of frogs seen in general/wild life

How many types of frog exist? What is the population of frogs?

In which geographical conduction will they live?

Which is the largest species of frogs?

Which is the smallest species of frogs?

Differentiate between frogs & toads on the basis of their appearance?

Are frogs nocturnal or diurnal?

Special feature in frogs?

Frog mutations & genetic defects?

Do all frogs sound the same?

What’s With That Tongue?

Characteristics?

Frog Groups?

Hide and Seek?

How Long Do Frogs Live?

Do Frogs Have Teeth?

Frog Colors?

Super skin?

Frogs and Weather?

Frog has big ears?

Various kinds of frog eyes?

3. Biology

Life Cycle

Life Span

Shapes & sizes of frogs & toads

Skin & color

Height & weight

Morphology

External features

Body Parts & their functions

Difference between male & female frog

How to distinguish between male & female frog by physical appearance

How to tell a frog’s gender by its color

Mating

Reproduction & development

Metamorphosis

4. Anatomy

Skeletal system

Respiratory system

Circulatory system

Nervous system

Digestive system

Absorption

Excretory system

Blood vascular system

Reproduction system

Muscular system

5. Movement

How do frogs move?

Why do frogs jump?

Why do frogs croak?

What does frog eats?

How does frog breathe?

How far frog can jump?

What is the breathing organ of frog?

How do frogs breathe underwater?

What is the movement of the hind legs when the frog swims?

Frog feet?

6. Behavior

Habitat

Locomotion

Breathing

Feeding

Hibernation

Diet/food

7. Relationship of human beings with frogs?

Conservation

Economic aspects of frog farming

Frogs are important in medical research that benefits humans

Doctor Frog to the Rescue

8. Threats

Habitat loss

Pollution & pesticides

Predators

Infectious diseases

Over harvesting for pets & food

9. Amazing facts about frogs

10. Production pipeline of Dissertation project

Preproduction level

Script

Model sheet

Storyboard

Model sheet

Reference images & videos

Shooting

Modeling

Blend shapes (used for Animation)

Unwrapping

Production level

Texturing

Rigging

Skinning

Tracking & Match move

Animation

Post production level

Lighting

Rendering

Editing & Compositing

Sound effects

11. Softwares used

Autodesk Maya (Modeling, Lighting & Rendering)

Headus UV layout pro (Unwrapping)

Autodesk Mud Box (Texturing)

PF Track (Tracking & Match move)

Fusion (Compositing)

Silhouette fx (Roto)

Adobe After effects (Title animations)

Adobe Photoshop

Microsoft office

12. Problems faced during project

Preproduction level

Shooting

Modeling

Production level

Texturing

Rigging

Skinning

Tracking

Match move

Animation

Postproduction level

Lighting

Rendering

Editing & compositing

Origin of word

O.E. frogga, a dim. of frox, forsc, frosc "frog," from P.Gmc. *fruska-z (cf. O.N. froskr, M.Du. vorsc, Ger. Frosch "frog"), probably lit. "hopper," from PIE root

*preu- "to hop" (cf. Skt. provate "hops," Rus. prygat "to hop, jump"). The Latin word (rana) is imitative of croaking. Collateral M.E. forms frude, froud are

from O.N. frauðr "frog," and frosk "frog" survived in English dialects into the 19c. As a derogatory term for "Frenchman," 1778 (short for frog-eater), but

before that (1650s) it meant "Dutch" (from frog-land "marshy land"). To have a frog in the throat "be hoarse" is from 1892, from the "croaking" sound.

Frog – Different languages

Afrikaans - Padda Indonisian - katak

America & Australia - Frog & Toad Iraq - A’groog

Frence - Crapaud or Ouaouaron Israel – Los’can

Arabic - Difda Italy - Ranocchia

Argentina - Rana Japan - Kaeru

Brazil - Sapo Jersey - Rainotte

Canada - Rania Kenya - chura

China - Qing Wa Korea - Gao Goo Lee

England - Ribbit-Ribbit Latin - Rana

France - Grenouille or Crapaud Latvian - Varde

Germany - Frosch Malaysia - Katak

Greek - Vatrahos Mexico - Sapo

Denmark - Tudse Netherlands - Kikker or Kikvors

Dutch - Kikker or Kikvors New Zealand – Froglet or Frog

Finland - Sammakko Nigeria - Awoli

Gujrathi - Beduk or Deduku Norway - trausk

Hindi - Mandek New Guinea - Rokrok or Balele

Holland - Kikker Lybia - Jrana

Hong Kong - Katie(Froggy) Lithuania - Varle

India - kerala (Makiri) or Madras (Tavalai) Hungary - Beka

Taxonomy of Frog

SCIENTIFIC CLASSIFICATION

KINGDOM

ANIMALIA

PHYLUM

CHORDATA

SUB PHYLUM

VERTEBRATA

CLASS

AMPHIBIA

SUB CLASS

LISSAMPHIBIA

ORDER

ANURA

FAMILY

RANIDAE

GENUS

RANA

SPECIES

PIPINS

COMMON NAME

GREEN, BRONZE FROG

SCIENTIFIC NAME

RANA CLAMITANS

Etymology

The name frog derives from Old English frogga, (compare Old Norse frauki, German Frosch, older Dutch spelling kikvorsch), cognate with Sanskrit

plava (frog), probably deriving from Proto-Indo-European praw = "to jump". A distinction is often made between frogs and toads on the basis of their appearance, caused by the convergent adaptation among so-called toads to

dry environments; however, this distinction has no taxonomic basis. The only family exclusively given the common name "toad" is Bufonidae, but

many species from other families are also called "toads," and the species within the toad genus Atelopus are referred to as "harlequin frogs".

Evolution

Until the discovery of the Early Permian Gerobatrachus hottoni in 2008, a stem-batrachian with many salamander-like characteristics, the earliest

known proto-frog was Triadobatrachus massinoti, from the 250 million year old early Triassic of Madagascar.The skull is frog-like, being broad with

large eye sockets, but the fossil has features diverging from modern amphibia. These include a different ilium, a longer body with more vertebrae, and

separate vertebrae in its tail (whereas in modern frogs, the tail vertebrae are fused, and known as the urostyle or coccyx). The tibia and fibula bones

are unfused and separate, making it probable Triadobatrachus was not an efficient leaper.

Another fossil frog, Prosalirus bitis, was discovered in 1995. The remains were recovered from Arizona's Kayenta Formation, which dates back to the

Early Jurassic epoch,[61] somewhat younger than Triadobatrachus. Like Triadobatrachus, Prosalirus did not have greatly enlarged legs, but had the

typical three-pronged pelvic structure. Unlike Triadobatrachus, Prosalirus had already lost nearly all of its tail[citation needed] and was well adapted

for jumping.

The earliest known "true frog" is Vieraella herbsti, from the early Jurassic (188–213 million years ago). It is known only from the dorsal and ventral

impressions of a single animal and was estimated to be 33 mm (1.3 in) from snout to vent. Notobatrachus degiustoi from the middle Jurassic is slightly

younger, about 155–170 million years old. It is likely the evolution of modern Anura was completed by the Jurassic period. The main evolutionary

changes involved the shortening of the body and the loss of the tail.

The earliest full fossil record of a modern frog is of sanyanlichan, which lived 125 million years ago and had all modern frog features, but bore 9

presacral vertebrae instead of the 8 of modern frogs.

Frog fossils have been found on all continents except Antarctica, but biogeography evidence suggests they inhabited Antarctica when it was warmer.

Entire History

Amphibians (the group of organisms to which frogs belong) are believed to have been the first vertebrates to leave the water and live on land.

Approximately 360 million years ago, amphibians left the sea and were successful on the land because of the lack of other vertebrates to hunt them.

Over the next 125 million years, 15 major groups of amphibians, including many species of frogs, evolved. However, once birds and other similar

predators arrived, this number declined to the three orders of amphibians that we have today: frogs and toads under the order Anura, salamanders

(Caudata) and the order Gymnophiona which includes a group of worm-like tropical organisms known as caecilians.

As the frogs and other amphibians moved to the land, they had to adapt in many ways: they needed new limbs that could let them travel on the

ground, lungs and moist skins for dealing with the air, skin that would not let water evaporate very easily, and eggs that wouldn't dry out and die in

the air. While frogs did make many of these adaptations, they were not entirely successful. Frogs still need water or at least a moist area to breed in

because the eggs still dry out easily. Their skins do not keep all of the water in, so many species spend most, if not almost all, of their lives in the

water. These missed adaptations are what keep frogs from living in extreme environments like deserts.

Like all amphibians, frogs are cold-blooded, which means that they cannot maintain their own body temperature as we humans can. Frogs must

maintain their body temperature by using their environment. Frogs also have to be careful of predators, including many fish, birds, reptiles, and

mammals.

Mythological status & Social role

Frogs and toads have always seemed to be close to the mythic origin of life. When relaxed, they have almost the form of a ball, the most primeval of

shapes. They are found mostly in ponds or in moist areas that suggest the chaos out of which living things were created.

People have long believed that frogs were generated spontaneously out of earth and water and that they could survive for centuries in stone. Frogs

also seemed to embody fertility when people observed their copulation, which can last for several days. The female frog will often lay tens of

thousands of eggs every year.

The Egyptian hieroglyphic sign for “one hundred thousand” was a tadpole (Houlihan). The transformation of a tadpole into a frog has been a model

for all of the myriad metamorphoses in myth and legend. That is why traditional stories so often contain frogs that are transformed into men or

women. Evolutionary theory partially confirms the intuition of early mythologists about the primal origin of frogs, since fossils of frogs have been

found going back at least 37 million years. The popular distinction between frogs and toads is not fully recognized by professional biologists. Both

groups of amphibians are members of the order Anura, and they are almost interchangeable in myth and legend. The word toad is generally, though

not always, used for creatures of the family Bufonidae, which have short legs, rough skin, and spend much of their time on land. Toads are generally

associated with cultivated places such as gardens, as well as with dark magic. But frog and toad, as the terms are often used, seem almost like words

for different aspects of a single creature.

The economy of ancient Egypt was centered on the Nile River, which teemed with frogs. The frog was particularly identified with Heket, a deity of

fertility and childbirth. When the waters of the Nile receded, innumerable frogs would be heard croaking in the mud, the sort of event that may have

influenced many myths. In one Egyptian creation myth, Heket and her ram-headed husband, Khnum, made both gods and human beings. According to

another Egyptian creation myth, the original eight creatures were frogs and snakes that carried the cosmic egg.

The Hebrews, who reacted violently against their Egyptian captors, found the frog unclean. The Bible tells us that when the pharaoh refused to let the

people of Israel leave Egypt, Yahweh sent Moses to him with the following threat, which he later carried out: “Know that I will plague the whole of

your country with frogs. The river will swarm with them; they will make their way into your palace, into your bedroom, onto your bed, into the houses

of your courtiers and of your subjects, into your ovens, into your kneading bowls. The frogs will even climb all over you, over your courtiers, and over

all your subjects”.

Frog Marriage for Rainfall in Dry spell INDIA

Frog marriage solemnized as prayer for rainfall, to please the Hindu Rain God “Barun” with a hope of early arrival of monsoon. There is a

mythological believe among Hindus that if the wild frogs caught by the people were got married with Vedic rites and traditional marriage rituals like

human beings, that can bring rainfall in coming days. Some places in INDIA also passing through a bad phase of dust storm and dry wave these

days followed by severe water crisis in paddy fields, which motivated the citizens to arrange frog marriage, with a hope for rainfall.

In Japan, frogs symbolize good luck. One myth dealt with the idea that bullfrogs are descendants of great ancestors who could suck all of the

mosquitoes out of a room in a breath.

Some myths don't favor frogs as well. Some folklorists claim that "If the first frog you see in spring is sitting on dry ground, it means that during the

same year you will shed as many tears as the frog would require to swim away." If the first frog is in water you'll experience misfortune all year. If the

first "hop toad" jumps toward you, you will have many friends, but if he hops away you will lose friends.

Some people associate frogs and toads with demons or devils.

Frogs have been associated with weather in many ancient cultures.

Many Australian aborigine and Native American groups believed that frogs brought rain.

In India, it is believed that frogs represent thunder in the sky. The word "frog" meant "cloud" in Sanskrit.

In China there is a "frog in the moon." Also toad is considered "one of the five poisons of yin." When eclipses happen it is said the "frog in the moon"

tries to swallow the moon.

Role in Stories

The Frog Prince

There was once a handsome young prince who had the misfortune to offend a wicked fairy. To avenge herself she turned him into an ugly frog and put him

into a well.

Now it happened that the well was in the courtyard of a king's palace and on fine days, when the sun shone warmly, the king's youngest daughter sometimes

came there to amuse herself by tossing a golden ball high into the air and catching it as it fell. The poor frog watched her running to and fro in the sunshine.

He thought she was the prettiest princess he had ever seen.

One day, the princess threw the ball up so high that when she stretched out her hand to catch it the ball bounced on the stones and fell with a splash into the

water. She ran to the edge of the well and gazed down. But the golden ball had sunk far, far out of sight. Only a little ring of bubbles showed her where it had

disappeared. She began to cry bitterly.

The frog popped his head out of the water. "Don't cry, Princess!" he said.

"What will you give me if I bring your ball from the bottom of the well?"

"Oh, I will give you anything I have," replied the princess. "My pretty pearls, my diamonds—even my crown. Only please bring my ball back to me!"

"I do not want your pearls or your diamonds or your crown," said the frog. "But if you will promise to love me,

and let me eat from your plate, and drink out of your cup, and sleep on your bed, I will bring your ball safely back

to you."

And the princess promised. For she said to herself, "What a silly frog! As if he could ever get out of the well and

walk all the way to the palace! He will never find me."

The frog dove to the bottom of the well and presently came up with the golden ball in his mouth.

The princess had no sooner snatched it from him than she forgot all about her promise and ran back to the

palace laughing with joy.

The next day, as she sat at dinner with the king and his courtiers, something came flopping up the great

staircase—flip flap, flip flap!

And a voice said:

"From the deep and mossy well,

Little princess, where I dwell,

When you wept in grief and pain

I brought your golden ball again."

The princess dropped her spoon with a clatter on her plate, for she knew it was the frog who had

come to claim her promise.

"What is the matter, daughter?" asked the king. "There is someone knocking at the door and your

rosy cheeks are quite pale."

Then the princess had to tell her father all that had happened the day before how she had

dropped her golden ball into the well, and how the frog had brought it up for her, and of the

promises she had given him.

The king frowned and said, "People who make promises must keep them. Open the door and let the frog come in."The princess opened the door very

unwillingly and the poor frog hopped into the room, looking up into her face with his ugly little eyes.

"Lift me up beside you," he cried, "that I may eat from your plate and drink out of your cup." The princess did as he asked her and was obliged to finish her

dinner with the frog beside her, for the king sat by to see that she fulfilled her promise. When they had finished, the frog said, "I have had enough to eat.

Now I am tired. Take me up and lay me on your pillow, that I may go to sleep.Then the princess began to cry. It was so dreadful to think that an ugly frog, all

cold and damp from the well, should sleep in her pretty white bed.But her father frowned again and said, "People who make promises must keep them. He

gave you back your golden ball and you must do as he asks."So the princess picked the frog up between her thumb and finger, not touching him more than

she could help, and carried him upstairs and put him on the pillow on her bed. There he

slept all night long. As soon as it was light he jumped up, hopped downstairs, and went out

of the palace.Now, thought the princess, he is gone and I shall be troubled with him no

more.But she was mistaken, for when night came again she heard tapping at the door of

her bedroom. When she opened it, the frog came in and slept upon her pillow as before

until the morning broke. The third night he did the same. But when the princess awoke the

following morning, she was astonished to see, instead of the frog, a handsome prince

standing at the head of her bed. He was gazing at her with the most beautiful eyes that

ever were seen.

He told her that he had been enchanted by a wicked fairy, who had changed him into the

form of a frog, in which he was fated to remain until a princess let him sleep upon her bed

for three nights.

"You," said the prince, "have broken this cruel spell and now I have nothing to wish for but

that you should go with me to my father's kingdom, where I will marry you and love you as

long as you live."

The princess took him to her father

and he gave his consent for them to

marry. As they spoke a splendid carriage drove up with eight beautiful horses decked with plumes of

feathers and golden harness. Behind rode the prince's servant, who had bewailed the misfortune of

his dear master so long and so bitterly that his heart had almost burst. Then all set out full of joy for

the prince's kingdom. There they arrived safely and lived happily ever after.

The Frog Story

A group of frogs were hopping contentedly through the woods, going about their froggy business, when two of them fell into a deep pit. All of the other frogs

gathered around the pit to see what could be done to help their companions. When they saw how deep the pit was, they agreed that it was hopeless and told

the two frogs in the pit that they should prepare themselves for their fate, because they were as good as dead.

Unwilling to accept this terrible fate, the two frogs began to jump with all of their might. Some of the frogs shouted into the pit that it was hopeless, and that

the two frogs wouldn't be in that situation if they had been more careful, more obedient to the froggy rules, and more responsible. The other frogs continued

sorrowfully shouting that they should save their energy and give up, since they were already as good as dead.

The two frogs continued jumping with all their might, and after several hours of this, were quite weary. Finally, one of the frogs took heed to the calls of his

fellow frogs. Exhausted, he quietly resolved himself to his fate, lay down at the bottom of the pit, and died.

The other frog continued to jump as hard as he could, although his body was wracked with pain and he was quite exhausted. Once again, his companions

began yelling for him to accept his fate, stop the pain and just die. The weary frog jumped harder and harder and, wonder of wonders, finally leaped so high

that he sprang from the pit.

Amazed, the other frogs celebrated his freedom and then gathering around him asked, "Why did you continue jumping when we told you it was impossible?"

The astonished frog explained to them that he was deaf, and as he saw their gestures and shouting, he thought they were cheering him on. What he had

perceived as encouragement inspired him to try harder and to succeed against all odds.

This simple story contains a powerful lesson. The book of Proverbs says, "There is death and life in the power of the tongue". Your encouraging words can lift

someone up and help them make it through the day. Your destructive words can cause deep wounds; they may be the weapons that destroy someone's

desire to continue trying - or even their life. Your destructive, careless word can diminish someone in the eyes of others, destroy their influence and have a

lasting impact on the way others respond to them. Be careful what you say Speak life to (and about) those who cross your path. There is enormous power in

words. If you have words of kindness, praise or encouragement -speak them now to, and about, others. Listen to your heart and respond. Someone,

somewhere, is waiting for your words.

The Scorpion and the Frog

One day, a scorpion looked around at the mountain where he lived and decided that he wanted a change. So he set out on a journey through the forests and

hills. He climbed over rocks and under vines and kept going until he reached a river. The river was wide and swift, and the scorpion stopped to reconsider the

situation. He couldn't see any way across. So he ran upriver and then checked downriver, all the while thinking that he might have to turn back.

Suddenly, he saw a frog sitting in the rushes by the bank of the stream on the other side of the river. He decided to ask the frog for help getting across the

stream."Hellooo Mr. Frog!" called the scorpion across the water, "Would you be so kind as to give me a ride on your back across the river?"

"Well now, Mr. Scorpion! How do I know that if I try to help you, you won’t try to kill me?" asked the frog hesitantly.

"Because," the scorpion replied, "If I try to kill you, then I would die too, for you see I cannot swim!"

Now this seemed to make sense to the frog. But he asked. "What about when I get close to the bank? You could still try to kill me and get back to the shore!"

"This is true," agreed the scorpion, "But then I wouldn't be able to get to the other side of the river!"

"Alright then...how do I know you won’t just wait till we get to the other side and THEN kill me?" said the frog.

"Ahh...," crooned the scorpion, "Because you see, once you've taken me to the other side of this river, I will be so grateful for your help, that it would hardly

be fair to reward you with death, now would it?!"

So the frog agreed to take the scorpion across the river. He swam over to the bank and settled himself near the mud to pick up his passenger. The scorpion

crawled onto the frog's back, his sharp claws prickling into the frog's soft hide, and the frog slid into the river. The muddy water swirled around them, but the

frog stayed near the surface so the scorpion would not drown. He kicked strongly through the first half of the stream, his flippers paddling wildly against the

current.

Halfway across the river, the frog suddenly felt a sharp sting in his back and, out of the corner of his eye, saw the scorpion remove his stinger from the frog's

back. A deadening numbness began to creep into his limbs.

"You fool!" croaked the frog, "Now we shall both die! Why on earth did you do that?"

The scorpion shrugged, and did a little jig on the drowning frog's back.

"I could not help myself. It is my nature."

Then they both sank into the muddy waters of the swiftly flowing river.

Tiny Frog

Once upon a time there was a bunch of tiny frogs.... who arranged a running competition. The goal was to reach the top of a very high tower. A big crowd had

gathered around the tower to see the race and cheer on the contestants.... The race began.... Honestly: No one in the crowd really believed that the tiny

frogs would reach the top of the tower. You heard statements such as: "Oh, WAY too difficult!!" "They will NEVER make it to the top."or: "Not a chance that

they will succeed. The tower is too high!"

The tiny frogs began collapsing. One by one.... Except for those, who in a fresh tempo, were climbing higher and higher....

The crowd continued to yell, "It is too difficult!!! No one will make it!" More tiny frogs got tired and gave up....

But ONE continued higher and higher and higher.... This one wouldn't give up! At the end everyone else had given up climbing the tower. Except for the one

tiny frog who,

After a big effort, was the only one who reached the top!

THEN all of the other tiny frogs naturally wanted to know how this one frog managed to do it?

A contestant asked the tiny frog how he had found the strength to succeed and reach the goal?

It turned out....

That the winner was DEAF!!!!

The wisdom of this story is: Never listen to other people's tendencies to be negative or pessimistic.... because they take your most wonderful dreams and

wishes away from you -- the ones you have in your heart! Always think of the power words have. Because everything you hear and read will affect your

actions!

Therefore: ALWAYS be....POSITIVE! And above all:

Be DEAF when people tell YOU that you cannot fulfill your dreams!

Once upon a time there was a bunch of tiny frogs.... who arranged a running competition.

The goal was to reach the top of a very high tower.

A big crowd had gathered around the tower to see the race and cheer on the contestants....

The race began....

Honestly:

No one in the crowd really believed that the tiny frogs would reach the top of the tower.

You heard statements such as:

"Oh, WAY too difficult!!"

"They will NEVER make it to the top." or:

"Not a chance that they will succeed. The tower is too high!"

The tiny frogs began collapsing. One by one....

Except for those, who in a fresh tempo, were climbing higher and higher....

The crowd continued to yell, "It is too difficult!!! No one will make it!"

More tiny frogs got tired and gave up....

But ONE continued higher and higher and higher....

This one wouldn't give up!

At the end everyone else had given up climbing the tower. Except for the one tiny frog who, after a big effort, was the only one who reached the top! THEN

all of the other tiny frogs naturally wanted to know how this one frog managed to do it?

A contestant asked the tiny frog how he had found the strength to succeed and reach the goal.

It turned out.... That the winner was DEAF!!!!

The wisdom of this story is:

Never listen to other people's tendencies to be negative or pessimistic.... because they take your most wonderful dreams and wishes away

From you -- the ones you have in your heart!

Always think of the power words have.

Because everything you hear and read will affect your actions!

Some more stories of frog

The Boys and the Frogs (one man’s fun may be another's pain)

Frog and Toad ( perception of beauty is subjective)

The Boiled Frog (a parable about adaptation)

The Quack Frog (a frog proclaims to be a doctor)

The Ass and the Frogs ( Men often bear little grievances with less courage than they do large misfortunes)

The Hares and the Frogs (There is always someone worse off than yourself)

The Mouse, the Frog, and the Hawk (Choose your allies carefully)

The Frogs Desiring a King (Better no rule than cruel rule)

The Frogs and the Well (Look before you leap)

Frog in a Milk-Pail (Never Give Up!)

The Ox and the Frog (Self-conceit may lead to self-destruction)

The Two Frogs (A willful man will have his way to his own hurt)

The Frog in the Shallow Well (a Chinese fable about one's place in the universe)

The Frog and the Crocodile (beware of your enemies!)

The Frogs' Complaint Against the Sun (too much of a good thing?)

Common Name Also Known As... Scientific Name Frog Type

African Bullfrog Bullfrog, Pixie Frog Pyxicephalus edulis Common Frog/Toad

African Clawed Frog Water Frog, Grow-a-Frog Kit, Albino variety Xenopus Laevis Aquatic Frog

African Dwarf Frog Aquababies Kits Hymenochirus boettgeri Aquatic Frog

Alpine Whistling Tree Frog

Whistling Tree Frog Litoria verreauxii Tree Frog

American Bullfrog Bullfrog Rana catesbeiana Common Frog/Toad

American Green Tree Frog

Green Tree Frog Hyla cinerea Tree Frog

Argentinian Horned Frog

PacMan Frog, Ornate Horned Frog, Bell Horned Frog, Albino variety

Ceratophrys ornata Common Frog/Toad

Asian Floating Frog Floating Frog, Indonesian Floating Frog Occidozyga Lima Common Frog/Toad

Asian Painted Frog

Chubby Frog, Narrow-mouthed Toad, Rice Frog, Bubble Frog

Kaloula pulchra Common Frog/Toad

Aquababies Kits African Dwarf Frog Hymenochirus boettgeri Aquatic Frog

Barking Tree Frog Hyla gratiosa Tree Frog

Bell Horned Frog

PacMan Frog, Argentinian Horned Frog, Ornate Horned Frog, Albino variety

Ceratophrys ornata Common Frog/Toad

Bubble Frog

Chubby Frog, Asian Painted Frog, Narrow-mouthed Toad, Rice Frog

Kaloula pulchra Common Frog/Toad

Bullfrog American Bullfrog Rana catesbeiana Common Frog/Toad

Bullfrog African Bullfrog, Pixie Frog Pyxicephalus edulis Common Frog/Toad

Cane Toads Bufo marinus Common Frog/Toad

Carpenter Frog Rana Virgatipes Common Frog/Toad

Catholic Frog Notaden bennetti Exotic

Chubby Frog

Asian Painted Frog, Narrow-mouthed Toad, Rice Frog, Bubble Frog

Kaloula pulchra Common Frog/Toad

Colored Frogs Poison Arrow Frogs, Poison Dart Frogs, Mantella Frogs genera Dendrobates, Phyllobates, Epipedobates, Mantella

Exotic

Coqui Puerto Rican Coqui Eleutherodactylus coquí Exotic

Cuban Tree Frog osteopilus septentrionalis Tree Frog

Dart Frogs

Poison Arrow Frogs, Poison Dart Frogs, Colored Frogs, Mantella Frogs

genera Dendrobates, Phyllobates, Epipedobates, Mantella

Exotic

Darwin's Frog Rhinoderma darwinii Exotic

Dumpy Tree Frog White's Tree Frog, Smiling Frog Litoria caerulea Tree Frog

Firebellied Toad Oriental Firebellied Toads Bombina Orientalis Common Frog/Toad

Floating Frog Asian Floating Frog, Indonesian Floating Frog Occidozyga Lima Common Frog/Toad

Gastric Brooding Frog Rheobatrachus silus Extinct?/Exotic

Gold Frog Psyllophryne Didactyla Exotic

Golden Bell Frog Growling Grass Frog Litoria aurea Common Frog/Toad

Goliath Frog Conraua goliath Exotic

Gray Tree Frog Hyla versicolor Tree Frog

Green Frog Rana clamitans Common Frog/Toad

Green Tree Frog American Green Tree Frog Hyla cinerea Tree Frog

Grow-a-Frog Kit African Clawed Frog, Water Frog, Albino variety Xenopus Laevis Aquatic Frog

Growling Grass Frog Golden Bell Frog Litoria aurea Common Frog/Toad

Indonesian Floating Frog Floating Frog, Asian Floating Frog Occidozyga Lima Common Frog/Toad

Leopard Frog Northern and Southern Leopard Frogs Rana pipiens, Rana sphenocephala Common Frog/Toad

Madagascan Burrowing Frogs

Scaphiophryne marmorata Exotic

Mantella Frogs Poison Arrow Frogs, Poison Dart Frogs, Colored Frogs genera Dendrobates, Phyllobates, Epipedobates, Mantella

Exotic

Mexican Leaf Frog Pachymedusa dacnicolor Exotic Frog/Toad

Monkey Frog Monkey Tree Frog Phyllomedusines Exotic Frog/Toad

Narrow-mouthed Toad Chubby Frog, Asian Painted Frog, Rice Frog, Bubble Frog Kaloula pulchra Common Frog/Toad

New Zealand Brown Tree Frog

Whistling Tree Frog Litoria Ewingii Tree Frog

Ornate Horned Frog

PacMan Frog, Argentinian Horned Frog, Bell Horned Frog, Albino variety

Ceratophrys ornata Common Frog/Toad

Pacific Tree Frog Hyla Regilla (also Pseudacris Regilla) Tree Frog

PacMan Frog

Argentinian Horned Frog, Ornate Horned Frog, Bell Horned Frog, Albino variety

Ceratophrys ornata Common Frog/Toad

Pixie Frog African Bullfrog, Bullfrog Pyxicephalus edulis Common Frog/Toad

Poisonous Frogs

Poison Arrow Frogs, Poison Dart Frogs, Colored Frogs, Mantella Frogs

genera Dendrobates, Phyllobates, Epipedobates, Mantella

Exotic

Puerto Rican Crested Toad

Peltophryne lemur Exotic

Puerto Rican Coqui Eleutherodactylus coquí Exotic

Red-Eyed Tree Frog Agalychnis callidryas Tree Frog

Rice Frog

Chubby Frog, Asian Painted Frog, Narrow-mouthed Toad, Bubble Frog

Kaloula pulchra Common Frog/Toad

Smiling Frog White's Tree Frog, Dumpy Tree Frog Litoria caerulea Tree Frog

Surinam Toad family Pipidae Aquatic Frog

Tomato Frog Dyscophus antongili, D. guineti, D. insularis Endangered/Exotic

Vietnamese Tree Frog Tree Frog

Water Frog Western Palearctic Water Frog various species of rana Common Frog/Toad

Water Frog Albino Clawed Frog, Grow-a-Frog Kit, Albino variety Xenopus Laevis Aquatic Frog

Western Palearctic Water Frog

Water Frog various species of rana Common Frog/Toad

Whistling Tree Frog New Zealand Brown Tree Frog Litoria Ewingii Tree Frog

White's Tree Frog Dumpy Tree Frog, Smiling Frog Litoria caerulea Tree Frog

Wood Frog Rana sylvatica Common Frog/Toad

How many types of frog exist?

There are about 3,500 species of frogs, and each year new owns are discovered. Frogs are amphibians and their body temperature is usually the same as their

environment. They are mostly nocturnal animals and avoid extreme sunlight and heat.

What is the population of frogs?

it is 200,000,000 .

In which geographical conduction will they live?

Frogs are found in every area of the world except near the North and South poles, the Sahara Desert and parts of Saudi Arabia. Emerging from a partially frozen pond more than 6,000 feet high in the Alps, European common frogs (Rana temporaria) set out to find mates and begin breeding activities. These frogs have adapted to a wide variety of conditions, increasing their range over most of Europe. Here on the Massif de Beaufort in the French region of Savoy, ice may not thaw until June, leaving only a brief window of warm weather for females to lay eggs and tadpoles to metamorphose into juveniles, known as froglets. Cold-climate frogs grow more slowly than their relatives in temperate areas, but live longer (12 years, compared to 5 for lowland frogs) and so grow larger. They're also active during warmer, daylight hours, unlike their kin elsewhere.

Frogs mate in a position called amplexus, with the smaller male clasping the female from behind in a ride that can last two days or more. As she lays

eggs, he expels sperm to fertilize them. Though egg laying takes place in spring, frog pairs in mountain ponds can begin hibernation in amplexus—a

months-long embrace that may provide a breeding advantage by allowing mating as quickly as possible once warm weather arrives. Eggs of high-

elevation frogs may be 30 percent larger than those of lowland females, giving tadpoles a head start. Eggs and tadpoles of mountain frogs have

developed resistance to genetic damage from ultraviolet radiation, a component of sunlight that is more intense in the thinner air of high altitude.

Temperature

Frogs can exist in a wide range of environments, from deserts to snowy mountains. Anurans body temperatures have been recorded from 3°' - 36°'C.

Frogs choose to live in these hostile environment because even though it can be tough, there is less competition for food and fewer predators.

Cold

Many frogs hibernate during cold seasons when the temperature can be as low as -7°C. They hide on the ground in leaf litter and under rocks or tree

roots.

The Wood Frog, rana sylatica, that lives in N.America and Canada, converts glycogen to glucose in their liver to produce an 'antifreeze'. This means

they can tolerate their body fluids freezing in the winter. They become stiff with no breathing or heart beat. Then thaw for the spring.

The Yosemite Toad, Bufo cenorus, walkes high up on tiptoe across snow to get to it's breeding area

Heat

Some frogs live in dry areas where water is precious. Many store water in their bladders. They reduce water evaporation by minimising their surface

area by closing their eyes and tucking in their limbs or several frog huddling together. Some frogs burrow into the ground to escape dry seasons.

Which is the largest species of frogs?

The biggest kind of frog is the Goliath frog (Conraua goliath). They come from Cameroon in West Africa. Their bodies can reach the size of nearly a

foot (30 cm) long.(remember: their legs are also AT LEAST that long)The Conraua Goliath weighs as much as a large housecat, about 3.3 kilos. Another kind of really big frog are called Cane toads, (also called "marine toads" or "giant toads"). Adult marine toads generally range in size from 6-9

inches (15-23 centimeters), but may get larger.

Which is the smallest species of frogs?

Two frogs are the smallest frogs in the world. Eleutherodactylus iberia (no common name) from Cuba and the Gold Frog Psyllophryne didactyla from

Brazil which measures only about 10 mm from the tip of the snout to the tail end. Gardiner's Seychelles frog is also in this size range. It's 5 to 6 times the size of the head of a pin.

The smallest frog is the Cuban coin frog. it size is 1cm. Recently found out in the Time For Kids magazine: they found an Amau its named after the place it has been found.

Differentiate between frogs & toads on the basis of their appearance?

Frogs and toads are a similar type of species. Both are amphibians of the Anura order. A toad is a type of frog, but it's not considered a true frog. Frogs

come from the Ranidae family, which contains over 400 species. Toads come from the Bufonidae family, which contains more than 300 species. A

group of frogs is known as an army of frogs and a group of toads is known as a knot of toads.

Evaluate their living quarters. Frogs make their habitat in or near water. Toads live on land, but breed in water. Frogs can be found on every continent

except Antarctica. Toads can be found in every part of the world except in Australasia, polar regions, Madagascar and Polynesia.

Check their hind legs and feet. Frogs have long hind legs and webbed feet. These features are perfect for swimming and jumping. Toads don't need

these features. They have short hind legs meant for walking.

Determine where they lay their eggs. Frogs lay eggs in water and in clusters that are surrounded by a jellylike substance. Toads also lay eggs in water

because their babies begin as tadpoles just like frog babies do. Toads lay eggs in long chains on the plant leaves that live in the water.

Note the differences in their bodies. Frogs have a narrow waist and body, making them look skinny. Toads have a flat and wide body, making them

look fat. Frog skin is smooth and slimy, which is why they prefer moist environments. Toad skin is bumpy, like warts. They prefer dryer climates

because their skin is dry. Their skin texture prevents bigger animals from eating them.

Are frogs nocturnal or diurnal?

Some are nocturnal and some are diurnal.

Special feature in frogs?

It has a long tongue to catch insects.

Frog mutations & genetic defects?

Frogs are amphibians and at times develop mutations of the body. Some mutations and genetic defects that frogs acquire include extra limbs or

misshapen legs. The first frogs with these genetic defects were found in August 1995 in south and central Minnesota by[citation needed]

Herpetologists. It is believed that these were not inherited defects but due to something in their environment that affected the frogs in their early

lives as eggs or tadpoles.

Types of frog mutations

Frog mutations can be triggered by natural causes and man-made causes.. These physical defects can be triggered by environmental factors or by parasites.

For example the African Clawed Frog can have many defects at birth; for example, some of African Clawed Frog's grow 6 toes on their feet or the frogs can

have a 5th finger that resembles a thumb.[1] When herpetologists observe mutations in frogs and their offspring they suspect such mutations may arise from

the frog's environment. Herpetologists then investigate for causes such as pesticides and other toxins.

Ribeiroia ondatrae

One natural cause for the mutations in frogs is Ribeiroia ondatrae a flatworm parasite and a contributor to recent increases in amphibian limb malformations

including, particularly missing, malformed, and extra hind legs. The exact mechanism of deformation has not been determined but it has been theorized that

deformation results from mechanical disruption of the cells involved in limb bud formation during the amphibian larval stage. The spread and distribution of

these flat worms is of concern and being studied by scientists.

Environmental causes of frog mutation

Frogspawn may be affected by environmental pollution and ultraviolet light

In the past several decades, decline in amphibian populationshas been occurring all over the world, for unexplained reasons which are thought to be

varied made it more difficult for the frogs to reproduce. There is evidence of chemical pollutants causing frog developmental deformities (extra limbs,

or malformed eyes). In 1996 herpetologists discovered other reasons for these mutations were due to chemical pollution. They also discovered that

frogs and other amphibians were sensitive to these chemical pollutants and pesticides were because they lived both on land and in water, making

them sensitive to pollution in both of these areas. Now herpetologists believe that increased UV radiation is affecting the frogs’ eggs, which float on

the surface of the water absorbing the UV rays.but of which pesticides may be a part.[3] For example, atrazine, an organic compound commonly used

as an herbicide, is known to have adverse effects on the sexual development of frogs: when exposed to even low levels of the substance, as many as

20% of frogs developed additionalovaries or testicles, or became hermaphrodites – individuals with both male and female reproductive organs. In

addition, a drop intestosterone levels in male frogs due to the atrazine caused theirlarynges to shrink, reducing the frogs' ability to issue matingcalls.

These changes

Frogs usually mutate because of environmental factors.citation needed] Herpetologists have also discovered that frogs and other amphibians breathe

through their skin, and pollution can build up in their bodies. Some herpetologists think that toxic metals and pesticides were building up in the frogs’

bodies, causing their second generation have defects in them.

Prevention

Lessening the use of pesticides and other man made factors may prevent frog mutation and genetic defects that may harm frog eggs and tadpoles.

Decreasing greenhouse gas emissions may be beneficial, as well as reducing ozone depletion which is believed to negatively affect frogspawn. The

world's environment benefits greatly because frogs help control the insect populations on planet Earth. If frog populations decline the world's insect

populations could increase leading to an ecological imbalance and possible insect overpopulation

Do all frogs sound the same?

No!

Every different species of frog makes it’s own special sound and it is only the male frog that can croak. They have a small sac in their throats that vibrates the air as they slowly let it out.

The sounds that frogs make are not what you’d expect. Did you know that there are frogs that chirp? Others can whistle, croak, ribbit, peep, cluck, bark and grunt.

What’s With That Tongue?

Frog’s tongues are attached to the front of their mouths rather than at the back like humans. When a frog catches an insect it throws its sticky tongue out of it’s mouth and wraps it around its prey. The frog’s tongue then snaps back and throws the food down its throat.

Characteristics?

Frogs have very good eyesight. They bulge out the sides of their heads in order for the frog to see in nearly all directions.

Frogs also have amazing sense of hearing. You can often tell the difference between a male and female frog by the size of their eardrum, which can be seen behind their eyes. If the eardrum is smaller than the eye, the frog is a female. On males their eardrum is the same size as the eye.

Frogs have very powerful back legs and webbed feet that help them jump great distances, as well as, swim. Frogs even use their legs to dig, or burrow, underground for hibernating. Certain frogs can jump up to 20 times their own body length in a single leap.

Every different species of frog has his or her own look. They come in many colors, patterns and sizes.

Frog groups?

An Army of Frogs.

Hide & seek?

Many frogs rely on the art of camouflage to avoid getting spotted by predators.

Some blend with their backgrounds, while others even change colors to match the backgrounds.

Can you spot the "Painted Chubby Frog" in the photo on the left? Hint: it looks just like the bark it likes to hang out on.

Can you spot the Hylid frog (Phrynohyas venulosa) on the tree on the right? This frog is often called the Grey Tree Frog.

Painted chubby frog Hyla frog

How Long Do Frogs Live?

It turns out that very little is known at all about the natural lifespan of frogs. Partially, this is because it's pretty hard to track a frog all its life! (I guess

they havent figured out a good way to put little tiny collars around their necks!)

However,some records show that in captivity, many species of frogs and toads can live for surprisingly long times. They seem generally average

somewhere between 4 and 15 years!

Recently I ran across a page where people were posting data about how long their species of frogs had lived in captivity.

The longest lifespan entered was a European Common Toad (Bufo bufo ssp.) at 40 years!!!!!

Other species which live to ripe old ages include:

Giant Toad (Bufo marinus): ranging between 7 and 24 years.

Green And Black Poison Dart Frog (Dendrobates auratus): ranging between 7 and 17 years.

Oriental Fire-bellied Toad (Bombina orientalis): ranging between 11 and 14 years.

Ornate Horned Frog (Ceratophrys ornata) ranging from 5 to 12 years.

Do frogs have teeth?

Most frogs do in fact have teeth of a sort.

They have a ridge of very small cone teeth around the upper edge of the jaw. These are called Maxillary Teeth.

Frogs often also have what are called Vomerine Teeth on the roof of their mouth.

They don't have anything that could be called teeth on their lower jaw, so they usually swallow their food whole. The so-called "teeth" are mainly

used to hold the prey and keep it in place till they can get a good grip on it and squash their eyeballs down to swallow their meal.

Frog colors?

Some frogs are so variable that it's hard to tell what species they are! The frog on the left and the frog on the right are both really the same species!

They are called Ornate treefrogs, or Leptopelis flavomaculatus and come in many different colors and shapes.

A Frog of a Different Color Some frogs can adjust their color according to changes in light, moisture, temperature, or even mood.

Whites Tree Frogs are usually light green colored. When they move out of a sunny spot into a damp, shady spot, however, they sometimes change to a light

brown color.

One type of frog survives in the desert by changing colors from brown to bright white during the bright, sunny hours of the day. The white would reflect the

sun so that it can keep from getting dried up in the heat.

Super skin?

Frogs have very special skin! They don't just wear it, they drink and breathe through it.

Frogs don't usually swallow water like we do. Instead they absorb most of the moisture they need through their skin.

Not only that, but frogs also rely on getting extra oxygen (in addition to what they get from their lungs) from the water by absorbing it through their

skin. Because frogs get oxygen through their skin when it's moist, they need to take care of their skin or they might suffocate. Sometimes you'll find

frogs that are slimy. This is because the frog skin secretes mucus that helps keep it moist. Even with the slimy skin, these frogs need to stay near

water. Toads on the other hand have tougher skin that doesn't dry out as fast, so they can live farther from water than most frogs.

In addition to jumping in water, frogs and toads can get moisture from dew, or they can burrow underground into moist soil.

Frogs shed their skin regularly to keep it healthy. Some frogs shed their skin weekly, others as often as every day! This looks pretty yucky...they start

to twist and turn and act like they have the hiccups. They do this to stretch themselves out of their old skin! Finally, the frog pulls the skin off over it's

head, like a sweater, and then (this is gross) the frog EATS It.

Frog weather?

Frogs and Weather

Frogs have been associated with weather in a lot of ancient cultures. I guess this really makes a lot of sense if you consider that they tend to

make a lot of noise before rain storms.

Some Australian aborigines and Native American groups believed that frogs were the bringers of rain.

In India, frogs were believed to personify thunder in the sky. Even the word for "frog" also meant "cloud" in Sanskrit!

In China, they see the "TOAD", not the "man" of the moon. The toad is also considered "one of the five poisons of yin." They say that eclipses

happen when the "toad in the moon" tries to swallow the moon itself!

Frogs and Luck

Sometimes, cultures associated frogs with good and bad fortune.

In Japan, frogs are the symbols of Good Luck. One myth I read dealt with the idea that bullfrogs are descended from a great ancestor who

could suck all the mosquitoes out of a whole room in a single breath!

Some myths are less favoring to frogs and toads. Some folklorists* have claimed that "If the first frog that you see in the spring is sitting on dry

ground, it signifies that during the same year you will shed as many tears as the frog would require to swim away in." If, on the other hand,

the first frog of spring jumps into the water, you'll experience misfortune all year! However, if the springs' first "hoptoad" come jumping in

your direction, you will have many friends; if it jumps away from you, you will lose some.

(sounds to me like it's best not to run into the first spring frog!)

Some less enlightened people associate frogs, and Toads in particular, as evil incarnations of demons or devils!

Frogs and Warts

Some say that you get warts from touching frogs and toads.

You get warts from human viruses, not from frogs and toads!

Frogs have slimy skin to stay moist when it is dry, and toads have bumpy skin to help camouflage them in their habitat. Some frogs and toads

have paratoidal glands which secrete poisons as protection which can cause skin irritations and may be poisonous to some species of animals,

but warts have nothing at all to do with the frogs themselves!

The French and the Frogs

For some reason, the French have been given the nickname Frogs...There are many different theories about how this came to be...

The story I had always heard was that the nickname dates waaay back to sometime around the 18th century, when Paris was surrounded by

many swamps...The French nobility that would visit Versailles apparently tended to refer to Parisians as frogs because of the swampy

surroundings...and only later did the term get picked up to describe the French in general.

Another story I've heard was that American soldiers adopted the nickname for the French during the World War II because they ate frog legs

and hid well when camouflaged.

I've also heard that a frog used to be on the French Flag, before the Fleurs de Lis was adopted when King Clovis took the throne....

In fact, there are so many stories....I don't think anyone really knows for sure...If you have any knowledge on the origin of this nickname.

Frog has big ears?

Frogs can hear using big round ears on the sides of their head called a tympanum. Tympanum means drum. The size and

distance between the ears depends on the wavelength and frequency of a male frogs call. On some frogs, the ear is very

hard to see.

Ever wonder how frogs that can get so LOUD manage not to hurt their own ears? Some frogs make so much noise that they

can be heard for miles! How do they keep from blowing out their own eardrums?

Well, actually, frogs have special ears that are connected to their lungs. When they hear noises, not only does the eardrum

vibrate, but the lung does too! Scientists think that this special pressure system is what keeps frogs from hurting themselves with their noisy calls.

Various kinds of frog eyes?

Frogs have variable kinds of eye types. The colored part of the eye is called the iris (EYE-iris). They can be brown, green, silver, red, bronze, and even

gold.

The pupils come in all kinds of shapes too!

Round pupils: Some frogs have round pupils just like you and me. Newts and Salamanders also have round pupils. Vertical pupils: Vertical pupils that look like a cat’s eye are really good for night vision and respond quickly to changes in light. Horizontal-Shaped pupils: These are the more common pupil, good for normal day-vision. Heart-Shaped pupils: I'm not sure if it serves any purpose, but it sure looks neat! Oriental fire-bellied Toads have this type of pupil. Some frogs have Triangular pupils, and some even have Star-Shaped pupils.

Life Cycle

The Egg

Frogs lay their eggs in water or wet places. A floating clump of eggs is called frog spawn. The large and slippery mass of eggs is too big to be eaten. This is

nature's way of protecting them. But, the smaller clumps of eggs will be eaten by the creatures living near or in the pond. The egg begins as a single cell.

Several thousand are sometimes laid at once. It becomes surrounded by a jellylike covering, which protects the egg. The female may or may not stay with the

eggs to take care of the young after she has laid them. The egg slowly develops. But, only a few develop into adults. Ducks, fish, insects, and other water

creatures eat the eggs.

The Cell Splits

The single cell in the egg eventually splits into two. These two split making four cells, and so on. Eventually, there are many cells in the egg.

The Embryo

The mass of cells in the egg come to form an embryo. Organs and gills begin to form, and in the meantime, the embryo lives off of its internal yolk. This

supplies it with nutrients for 21 days. Then . . .

The Tadpole

After its 21 day development period, the embryo leaves its jelly shell, and attaches itself to a weed in the water. This quickly becomes a tadpole, a baby frog.

The tadpoles grow until they are big enough to break free into the water. This can take from 3 days to 3 weeks, depending on what kind of frog they will

become. They eat very small plants that stick to larger plants in the water. These tiny plants are called algae. The tadpole has a long tail, and lives in the

water. It is extremely vulnerable, and must rely on its camouflage to protect it.

The tadpole has a long tail, and lives in the water. It is extremely vulnerable, and must rely on its camouflage to protect it. The tadpoles also face danger by

being eaten by other water animals. Sometimes the pond dries up. As a result the tadpoles die.

The Tadpole Begins To Change

After about five weeks, the tadpole begins to change. It starts to grow hind legs, which are soon followed with forelegs. Behind their heads bulges appear

where their front legs are growing. Their tails become smaller. Lungs begin to develop, preparing the frog for its life on land. Now and then, they wiggle to

the surface to breathe in air. The tail becomes larger and makes it now possible for the tadpole to swim around and catch food. They eat plants and

decaying animal matter. Some tadpoles eat frogs eggs and other tadpoles.

Almost There . . .

Over time, the tadpole becomes even more froglike. They have shed their skin and lips. Its mouth widens, and it loses its horny jaws. The tail becomes much

smaller, and the legs grow. The lungs are almost functioning at this point.

The Frog

Eleven weeks after the egg was laid, a fully developed frog with lungs, legs, and no tail emerges from the water. This frog will live mostly on land, with

occasional swims. The tiny frogs begin to eat insects and worms. Eventually, it will find a mate. The way this is done varies depending on the species. The

female lays the eggs, the male fertilizes them, and the whole process begins again.

Life Span

Frogs and toads can live for many years; though little is known about their life span in the wild, captive frogs and toads are recorded living up to 40

years.

Although it is not common knowledge, some species of frog in their tadpole stage are known to be carnivorous. Early developers who gain legs

may be eaten by the others, so the late bloomers survive longer.

Shapes & sizes of frogs and toads

Frogs vary greatly in size. Members of the treefrog family, some less than 1 inch long, are more frequently heard than seen. The true frog family includes the largest frog in Minnesota, the bullfrog, which may measure up to 8 inches in length. In general, adult female toads and frogs are larger than males of the same species.

Characteristics useful in identifying toad and frog species: Tympanum, Dorsolateral fold, Cranial ridge, Paratoid gland.

The presence and size of the tympanum, a round disc that covers the external ear opening, is useful in determining the sex of some species. The tympanum of male Cope's gray treefrogs, gray treefrogs, bullfrogs, green frogs, and mink frogs is larger than the eye of the frog. The females of

these species have tympanums equal to the size of their eye. Distinguishing between males and females is easiest during the breeding season, when male toads and frogs have a darker throat color and male toads grow pads on their thumbs.

Skin and colour

The predominant colours in the common frog are green, yellow, brown and black, with whitish areas on the underside. The mottled patterning of these colours is thought to be of protective value in camouflaging the animal in its natural surroundings. The frog's colour can change to some extent, expansion or contraction of pigment cells in the skin making the frog darker or lighter. Such tones may correspond more closely to the frog's background in different circumstances and help to conceal it, but in many amphibia, temperature and humidity play a part in causing colour changes. The colour change operates through the sense organs and brain. A hormone from the pituitary gland circulates in the blood stream and has an effect on the pigment in certain cells.

In the skin are mucous glands which make the slimy fluid that covers the body. The sliminess makes the frog difficult to catch and keeps the skin moist. In the toad, a special group of glands behind the eyes produces an unpleasant poisonous substance that may serve as protection against enemies.

Many frogs are able to absorb water and oxygen directly through the skin, especially around the pelvic area. However, the permeability of a frog's skin can also result in water loss. Some tree frogs reduce water loss with a waterproof layer of skin. Others have adapted behaviours to conserve water, including engaging in nocturnal activity and resting in a water-conserving position. This position involves the frog lying with its toes and

fingers tucked under its body and chin, respectively, with no gap between the body and substrate. Some frog species will also rest in large groups, touching the skin of the neighbouring frog. This reduces the amount of skin exposed to the air or a dry surface, and thus reduces water loss. These adaptations only reduce water loss enough for a predominantly arboreal existence, and are not suitable for arid conditions.

Camouflage is a common defensive mechanism in frogs. Most camouflaged frogs are nocturnal, which adds to their ability to hide. Nocturnal frogs usually find the ideal camouflaged position during the day to sleep. Some frogs have the ability to change colour, but this is usually restricted to shades of one or two colours. For example, White's tree frog varies in shades of green and brown. Features such as warts and skin folds are usually found on ground-dwelling frogs, where a smooth skin would not disguise them effectively. Arboreal frogs usually have smooth skin, enabling them to disguise themselves as leaves.

Certain frogs change colour between night and day, as light and moisture stimulate the pigment cells and cause them to expand or contract.

Height & Weight

The height is 4in and the average weight is 3-8 pounds.

The height of big frog is ... They can reach up to 3" ( 7.6 cm) Male Red Eyed Tree Frogs- the largest size for a male is 2 ¼" (5.7 cm).

Brazilian Gold frog is the smallest frog length ranges from 19 to 38 mm (that is only 0.75 to 1.5 inches).

The smallest frog in North America is the Little Grass Frog (Pseudacris / Limnaoedus ocularis), which ranges in length from 7/16 to 5/8 inches.

Morphology

The skin is smooth and slippery due to the presence of mucus. The skin is always maintained in a moist condition. The colour of dorsal side of body

is generally olive green with dark irregular spots. On the ventral side the skin is uniformly pale yellow. The frog never drinks water but absorb it

through the skin.

Body of a frog is divisible into head and trunk. A neck and tail are absent. Above the mouth, a pair of nostrils is present. Eyes are bulged and

covered by a nictitating membrane that protects them while in water. On either side of eyes a membranous tympanum (ear) receives sound

signals. The forelimbs and hind limbs help in swimming, walking, leaping and burrowing. The hind limbs end in five digits and they are larger and

muscular than fore limbs that end in four digits. Feet have webbed digits that help in swimming. Frogs exhibit sexual dimorphism. Male frogs can

be distinguished by the presence of sound producing vocal sacs and also a copulatory pad on the first digit of the fore limbs which are absent in

female frogs.

External features

The frog is poikilothermic i.e. its body temperature varies with that of its surroundings. It has a loose-fitting moist skin. Its eyes protrude in such a way that they are above water when the rest of the body is immersed. The eyes have movable lids but, in addition, the whole eyeball can be

withdrawn farther into the head by muscles. This can be seen to happen sometimes when the frog is swallowing. Its nostrils are situated so that air can be breathed while the frog is swimming at the surface; they can also be closed. Behind the eyes are circular ear-drums. Sounds in the air or water set these thin membranes vibrating, the vibration being transmitted by a small bone to a sensory region which sends nervous impulses to the brain.

Frog Body Parts and Functions

Many of a frog's body parts have specialized jobs that help frogs survive both on land and in the water, like skin, legs, feet, eyes and tongue.

Frog Tongues

A body part exclusive to the frog is a tacky tongue connected to the front of the mouth so that it can flick out, curl around prey like a dragonfly, and swallow

it very quickly.

Frog Teeth

While not commonly known, frogs do have teeth called maxillary teeth, along the top of the jaw. Some frogs also have teeth on the roof of the mouth called

vomerine teeth.

Frog Legs

Frogs have long back legs, designed like springs to help them jump very long distances, up to 33 feet according to Leaping Frogs. The front legs of a frog are

much shorter.

Frog Feet

Frogs are excellent swimmers and jumpers because of their multifunctional feet. Frog feet are webbed between the toes for swimming; some have tiny little

suction cups on their toes to help them climb; and a few frogs have claws for protection.

Frog Skin

The slippery skin that covers the frog's body is made of two permeable layers allowing the frog to breathe under water by permitting oxygen to pass through

the skin.

Frog Eyes

Like humans, frog eyes can come in a variety of colors. According to All About Frogs, the iris of the frog's eye, the black center part of the eye, can also come

in different shapes.

Functions of the body parts

External nares or nostrils - Anterior openings for the entry or exit of air.

Esophagus - Tube that connects the mouth and the stomach in a frog.

Tympanic Membrane - The eardrum - receives sound waves

Glottis - The opening from the mouth into the respiratory system

Tongue - Muscular structure attached to the front of the mouth which is extended to catch insects (its food).

Maxillary Teeth - Sharp teeth in the maxilla of a frogs mouth that function in holding captured prey.

Vomerine Teeth - Small projections in the top of a frog’s mouth that function in holding and captured prey.

Eustachian tube openings - Openings in the mouth that lead to tubes that connect to the middle ear to equalize air pressure

Functions of the External Anatomy of the Frog

Nictitating Membrane - A transparent part of a frog’s lower eyelid that moves over the eye to clean it and protect it.

Cloacal Opening - Opening of cloaca through which undigested food, urine, eggs, and sperm are passed.

Differences between a Male & Female Frog

Physical Features

In many frog species, the external physical features are identical between male and female frogs, but this is not always the case. In many cases, the

female is larger than the male because she must carry a large amount of eggs. Males mount the females during breeding, and they are usually smaller

so as not to crush the female partner. Females are often darker as well. In many species, males develop tiny pads on their front legs during mating

season. Females tend to have thinner arms than males and are usually more plump.

Genitalia

All male and female frogs have different genitalia and internal sexual organs that allow them to breed. The sex organs on a frog are internal, however,

so it is often difficult to tell the difference between males and females just by looking at them. Males have two internal testicles and a spermatic canal

in which they produce sperm to fertilize the eggs. Female frogs have ovaries, oviducts and uteri. Both males and females have a cloaca, an orifice

through which digestive waste and reproductive products, such as eggs and sperm, exit the body. The cloaca is usually more visible in females.

Behavior

Males and females behave similarly, but in most species only the males sing. They do this during mating season to attract the females. If you hear the

frog singing or notice it has a vocal sack, it is most likely a male. In some cases, both males and females sing, but their song is different. Also, only male

frogs try to mount other frogs, even if the frog they are mounting is not female. Male frogs will often mount other things such as logs, rocks and even

people's shoes, mistaking them for female frogs. If you see a frog behaving this way, it is definitely male.

Mating

The most obvious difference between male and female frogs is the role they play in mating. During mating, the female is submissive while the male

jumps on top of her as she lays her eggs. The male fertilizes the eggs as they are released. Neither males nor females watch over the eggs or take care

of the young, who will soon hatch into tadpoles and fend for themselves.

Differences among Species

There are some species of frogs that have unique characteristics that differentiate males and females. Male bullfrogs and green frogs, for example,

have larger eardrums than their female counterparts. In many tropical frog species, the male frogs have brighter colors than the females. Some frogs,

such as African reed frogs, even change sex when the opposite sex is not present.

How to Distinguish Between Male and Female Frogs

Male and female frogs and toads lack the familiar external markings that male and female mammals possess. There are a few ways to tell male and

female frogs and toads apart from one another

Measure the frog or toad. Female frogs and toads are usually larger than their male counterparts because they carry many eggs, which are larger and

require more body volume than sperm. Distinguishing between male and female frogs may be difficult using measurements if you are looking at a

single frog and do not have another one to compare it to.

Examine the thumbs. During breeding season, the thumbs of male frogs and toads are swollen and often have roughened black patches to enhance

the ability they have to grip the females. These landmarks can only be used during the breeding season, because after breeding season the males'

thumbs will begin to have a normal appearance.

Listen to the noises it makes. Only male frogs call for mates, so if a frog is singing it is a male. Both males and females have the ability to make

vocalizations in times of distress so simply making a sound is not a good indicator of gender.

Look at the vocal sac, which is the pouch just underneath the chin. During the breeding season, the vocal sacs of males can appear darkened. They

begin to appear normal again after breeding, so this landmark can only be used during the breeding season.

See who is on top. During breeding, male frogs grasp females from behind and climb on top of their backs. If you find two frogs mating, the one on top

is a male.

How to Tell a Frog's Gender by Its Color

Many frog species exhibit color differences between the male and female that help pet owners or observers tell them apart. Although many times

frogs exhibit gender differences elsewhere on their bodies, such as on the digits on their hands, this method offers the most obvious way to tell the

two sexes apart. Learning to tell these variances apart will help you identify male and female frog pets in captivity or in the wild. Note that additional

sexing methods, such as checking the digits and assessing overall size, may be necessary to classify a frog as a male or female

Compare two frogs side by side, if possible.

Check which frog is lighter in color. Female frogs exhibit a duller, lighter coloring than males. Males generally exhibit dark skin.

Confirm the color identification by comparing size. Female frogs grow larger than male frogs, in most cases.

Mating

In mid-March 2005 frogs began mating in the small garden pond, as they have done for the last few years. This pair, pictured below, were quietly celebrating

the arrival of spring in the way that frogs do . . .

when they were joined by another pair, and a lone male. The lone male proceeded to try to mate also, and became rather disruptive, trying to displace the

males by a variety of pushing and shoving tactics, as shown in the photos on the right. This activity was accompanied by a lot of what sounded like bad-

tempered croaking. I was gardening at the time, and every now and then the peace and quiet was disturbed by frog squabbles.

Frog faces tend to look a bit glum and resigned generally, in an endearing kind of way. The faces in these photos appeared even more fed-up with it all, as

three males tried to mate with two females.

The situation seemed to resolve itself after a few days, with several clumps of frogspawn as a result.

The lone frog moved from one pair to the other. Here he's making his presence felt but not actually butting in.

Frog faces tend to look a bit glum and resigned generally, in an endearing kind of way. The faces in these photos appeared even more fed-up with it all, as

three males tried to mate with two females.

The situation seemed to resolve itself after a few days, with several clumps of frogspawn as a result.

Reproduction

Frog reproduction is pretty straightforward. The adult comes into breeding condition around about Springtime, and they migrate to ponds where they

pair up in a position known as amplexus The females lays her spawn, the male releases his sperm at the same time to fertilise the eggs and, after the

adults have left the water, the eggs hatch into tadpoles. They eventually grow legs, lose their tails and come out of the water to make their home in

the surrounding countryside.This is an extremely simplified account of frog reproduction, as it is in fact an incredible aspect of biology.

At each stage in the cycle, there can be variations, and up to half of the species, will depart from the conventional reproductive activity and do

something completely different.

The frog reproduction cycle can involve external or internal fertilisation; the eggs might be laid in the water, or they might not, and some species give

birth to live young.

Before spawning can take place, the adult frogs need to be in a state of being able to reproduce. This is determined by whether they feed well, and

thus are able to produce the male and female sex cells. In female frogs, this is eggs, or ova, and in males, it is sperm.

The pituitary gland is the gland that stimulates the production of these sex cells. The pituitary gland itself is stimulated by external factors such as

rainfall, daylength and temperature.

The frog reproduction cycle that happens at around the same time each year is known as cyclic breeding. This means that their ovaries or testes

follow a pattern each year. In areas where conditions are favourable and suitable for breeding, the breeding season is quite long compared to others.

For example, tropical frogs begin to breed at the beginning of the rainy seasons and will continue being able to breed until the start of the dry season.

This can be for as long as nine or even ten months of a year. The males at this time will call every night, and the females that are ready to lay their

eggs will visit the male frogs.

Frog reproduction - the mating call.

Did you know that frogs were the first animals to evolve a true voice? In frogs, the sound is produced by the movement of air over the vocal cords.

Just before it calls, the frog fills its lungs with air and closes its mouth and nostrils. As the air moves forwards it inflates the vocal pouch. By moving the

air forwards and backwards from the body to the pouch, lots of different sounds can be produced - croaks, chuckles, warbles and whistles, depending

on the species.

Usually, the small frogs have high-pitched calls and large frogs have low-pitched calls. It is important to note that each species of frog has a unique

'sound' to which only the frogs of the same species will react. This is important where there are a few different species living close to each other, as it

avoids the females mating with the wrong species and therefore wasting their eggs. This is known as a pre-mating isolating mechanism.

Where there are species that do not share their habitat with other species, some times the male frog does not call.

In general terms, a frog needs to own its own territory in order to attract a mate. Male frogs do tend to go to huge efforts to make sure their territory

is defined and well defended. They use their call to let other males know that that particularly territory is already owned.

In experiments, it has been found that a female will be attracted to the call which is loudest, and which goes on the longest. When the females arrive

at the pond and enter the water, the male frogs will mill around and grasp at a ripe female. However, they will grasp at anything that is roughly the

right size such as a piece of wood. Once the male lands on a ripe female he will often find that other males try to become involved, in which case the

successful male will tend to kick away the others with a hind foot. The female will spawn and leave the pond, and the male will return to the other

males in the hope of finding another mate. This goes on for a period of three or four nights, and gradually as the supply of females dries up, the males

will desperse.

Frog reproduction: Amplexus

Once the male has found a mate, he takes up a position in which he can fertilise the eggs. This usually happens outside the female body, just after the

eggs have been laid and before the jelly that will surround them has swelled. To make sure that the male frog's sperm comes into contact with as

many of the eggs as possible, he needs to position his cloaca as close as he can. This position is known as amplexus.

In order for the male frog to be able to keep a firm grip on the female frog so that he doesn't fall off during this mating, most frogs have nuptial pads.

These pads have a rough surface and are often quite heavily pigmented. They form on the outer edge of the thumb of a sexually active frog or toad.

These nuptial pads help prevent the frog from losing his grip during the mating act.

Development

The jelly round the eggs in the familiar frog-spawn has several advantages. It sticks them together and prevents their being swept away or eaten. It protects them from mechanical injury, from drying up and, probably, from attacks by fungi and bacteria.

The egg itself is a small sphere of semi-liquid cytoplasm in a tough, black egg membrane. There is a nucleus, and the lower cytoplasm contains yolky granules that are the only food supply for the first weeks of development. Sufficient oxygen must be able to diffuse through the jelly and the egg to allow the vital processes to go on.

Shortly after fertilization, the time depending partly on the temperature, the nucleus of the egg divides into two smaller nuclei which separate. The cytoplasm then divides to include each nucleus in a separate unit of cytoplasm so that there now appear two smaller cells, each with a nucleus.

A similar division takes place again in each cell but at right angles to the first division, making four smaller, roughly equal cells.

A third division takes place in the four cells, this time at right angles to the other two, round the "equator", forming eight cells of which the lower four are slightly larger than the upper four.

The cells continue to divide again and again until the "egg" becomes a hollow ball of tiny cells. The cells are very numerous and too small to be seen even with a hand lens. There is little increase in size during this division or cleavage but a great increase in the number of cells and nuclei. The egg has become an embryo, but to a casual observer it is still a spherical black ball and there is little evidence of the vigorous activity that has been going on.

All this happens in the first day or two. Later the sphere begins to elongate and develop a distinct head and tail. Meanwhile the cells are being organized internally to form the structures and organs of the tadpole. The energy and raw materials for this process come from the yolk.

After about ten days the jelly immediately round the tadpole liquefies and the tadpole can be seen moving about inside. The liquefaction also makes it easier for the tadpole to wriggle out of the jelly and into the water. At this stage its mouth has not yet opened and it is still digesting and using the remains of the yolk in its intestine. It clings to waterweed or to the surface of its jelly by its mucous glands which produce a sticky secretion. The tadpole is quite black, and the rudimentary external gills are visible, but it breathes through its skin at this stage.

Although the tadpoles are merely attached to, and not feeding on the waterweed, a good deal of spasmodic wriggling takes place in the clusters of tadpoles.

In two or three days the mouth has opened and the tadpoles can scrape the coatings of microscopic plants and other deposits from the surface of pondweeds using a pair of horny jaws and frilly lips. The three pairs of external, branched gills have developed and the blood can be seen circulating in them under the low power of a microscope. These gill filaments are thin-walled and present a fairly large surface area to the water. Oxygen dissolved in the water passes through the filament walls and into the blood close to the surface.

After about three weeks the mucous glands ‘disappear’ and a distinct division into body and tail occurs, together with a rapid increase in size. Internal gills are formed, opening to the outside by a single hole, the spiracle, on the left side. The fold of skin enclosing the space outside the gills is called the operculum.

By now the external gills have shrivelled and been reabsorbed into the body. In breathing, water is taken in through the mouth, passed over the internal gills, through the gill slits into the gill chamber formed by the operculum and, finally, out through the spiracle. As the water passes over the gill filaments, dissolved oxygen diffuses into the blood.

The tail elongates and develops a broad transparent web along its dorsal and ventral surfaces. Vigorous wriggling movements of the body and tail propel the tadpole through the water in a similar way to a fish but with less speed and precision.

A long, coiled intestine has developed and can be seen through the skin of the abdomen. The long intestine is adapted to the digestion of an exclusively vegetable diet. Eyes and nostrils are easily seen at this time. In this stage the tadpole grows considerably in size with little pronounced change in form for two or three weeks.

At two months from hatching, the tadpole comes to the surface frequently to gulp air into its lungs, which have begun to form. The hind-limb buds near the junction of the body and tail begin to grow and develop into perfect legs. The front legs also grow but do not yet appear because they are covered by the operculum; nevertheless they can be seen bulging beneath the skin in this region. The hind limbs are not yet used for locomotion but hang limply by the side of the body while the fish-like wriggling movements take place. The diet changes from vegetation, and the tadpoles nibble preferentially at dead animals or raw meat, at least in the aquarium, and associated with this is the shortening of the intestine and, later, the narrowing of the abdominal region.

Metamorphosis

At about three months, the front legs break through the operculum, the left leg appearing first by pushing through the spiracle while the right has to rupture the operculum. The tail shortens, being internally digested and absorbed, so providing a source of nutriment for the tadpole which has stopped feeding. The skin is shed, taking with it the larval lips and horny jaws, leaving a much wider mouth. Finally, the young frog climbs out of the pond on to the land, still with a tail stump, but using its legs for jumping and swimming. These changes take place within about four weeks. The young frogs remain in the damp vegetation and long grass in the vicinity of the pond, catching and eating small insects. In four years the frog will be old enough to breed.

The times given for development are only approximate since the temperature of the pond-water can alter the rate of metamorphosis from days to weeks and vice versa. It is more reliable to refer to the phase of development, e.g. hind-leg stage or external-gill stage, rather than age in days.

Skeletal system

Lissamphibia

Frog Skeleton - Dorsal View

Frog Skeleton - Ventral View

Frog vertebral column & pelvis, dorsal view (top) & ventral view (bottom).

Frog pectoral girldes- on the left is a ventral view of pectoral girdle showing sternal elements, clavicles &

coracoids. & on the left is a dorsal view of the suprascapulae.

Frog - semi-articulated front limbs

Frog - semi-articulated hind limbs

Parts of Skeletal System

They have 159 bones

Metatarsus

Part of the hind limb formed of five long parallel bones; it connects the tarsus with the first phalanges of the digits.

Tarsus

Part of the hind limb formed of several short bones; it is located between the tibiofibula and the metatarsus.

Sternum

Long flat bone located in the mid- ventral portion of the body; the clavicle and the coracoid, in particular, are attached to it.

Phalanges

Bones articulating to form the skeleton of the digits.

Clavicle

Long bone located between the sternum and the scapula.

Phalanges

Bones articulating to form the skeleton of the digits.

Metacarpus

Part of the forelimb formed of four long bones; it connects the radio-ulna to the first phalanges of the digits.

Radio-ulna

Located between the humerus and the metacarpus, the radius and the ulna fuse to form one long bone.

Humerus

Long bone of the forelimb articulating with the scapula and the radio-ulna.

Tibiofibula

Located between the femur and the tarsus, the tibia and the fibula fuse to form one long bone.

Femur

Long bone of the hind limb articulating with the ilium and the tibiofibula.

Ischium

Bone situated behind the ilium.

Urostyle

Long bone of the posterior portion of the central bony axis; it is formed by several fused vertebrae.

Ilium

Large flat bone articulating backward with the sacral vertebra; the juncture of the ilium and the ischium is where the hind limb is attached.

Sacral vertebra

Short vertebra located in the posterior portion of the central bony axis and articulating with the ilium.

Vertebrae

Short bony parts of the dorsal area of the body forming the central bony axis.

Scapula

Large flat back bone.

Coracoid

Ventral bone articulating with the sternum; the juncture of the scapula, clavicle and coracoid is the point where the hind limb is attached.

Atlas

First cervical vertebra supporting the head and supported by the axis.

Frontoparietal

Large flat bone of the upper anterior portion of the cranial box.

Mandible

Smooth curved movable bone comprising the lower jaw.

Maxilla

Toothed bone comprising the upper jaw.

Respiratory System

The respiratory system consists of the nostrils(nares), the glottis, and the bronchi which open into two lungs, hollow sacs with thin walls. The walls of the lungs are filled with capillaries, which are microscopic blood vessels through which materials pass into and out of the blood.

Circulatory System

The circulatory system consists of the heart, blood vessels, and blood. The heart has two receiving chambers, or atria, and one sending chamber, or ventricle. Blood is carried to the heart in vessels called veins. Veins from different parts of the body enter the right and left atria. Blood from both atria goes into the ventricle and then is pumped into the arteries, which are blood vessels that carry blood away from the heart. The heart is contained in a protective sac called the pericardium.

Nervous System

It is represented by a brain, a spinal cord, cranial nerves, spinal nerves and the autonomic (sympathetic and parasympathetic) nerves. Brain and spinal cord together form the central nervous system. Brain consists of a pair of olfactory lobes, a pair of cerebral hemispheres, a pineal body, a pair of optic lobes a cerebellum and a medulla oblongata. The spinal cord extends from medulla oblongata up to the tip of the trunk. Ten pairs of cranial nerves arise from the brain and innervate the different parts of the body. Ten pairs of spinal nerves arise from the spinal cord and supply to different parts of the body. The autonomic nerves are formed by two strands of nerves one on either side and parallel to the spinal cord.

Nervous System

The nervous system is organized into following

1. Central Nervous System (brain and spinal cord),

2. Peripheral Nervous System (cranial and spinal nerves)

3. Autonomic Nervous System (sympathetic and parasympathetic).

There are ten pairs of cranial nerves arising from the brain. Brain is enclosed in a bony structure called brain box (cranium). The brain is divided into fore-brain, mid-brain and hind-brain. Forebrain includes olfactory lobes, paired cerebral hemispheres and unpaired diencephalon. The midbrain is characterised by a pair of optic lobes. Hind-brain consists of cerebellum and medulla oblongata. The medulla oblongata passes out through the foramen magnum and continues into spinal cord, which is enclosed in the vertebral column.

Sense Organs

Frog has different types of sense organs, namely organs of touch (sensory papillae), taste (taste buds), smell (nasal epithelium), vision (eyes) and hearing (tympanum with internal ears). Out of these, eyes and internal ears are well-organised structures and the rest are cellular aggregations around nerve endings. Eyes in a frog are a pair of spherical structures situated in the orbit in skull. These are simple eyes (possessing only one unit). External ear is absent in frogs and only tympanum can be seen externally. The ear is an organ of hearing as well as balancing (equilibrium).

Digestive System

Fat Bodies

Spaghetti shaped structures that have a bright orange or yellow color, if you have a particularly fat frog, these fat bodies may need to be removed to see the other structures. Usually they are located just on the inside of the abdominal wall.

Messentary (Peritoneum)

A spider web like membrane that covers many of the organs, you may have to carefully pick it off to get a clear view.

Liver

The largest structure of the the body cavity. This brown colored organ is composed of three parts, or lobes. The right lobe, the left anterior lobe, and the left posterior lobe.The liver is not primarily an organ of digestion, it does secrete a digestive juice called bile. Bile is needed for the proper digestion of fats.

Gall bladder

Lift the lobes of the liver, there will be a small green sac under the liver. This is the gall bladder, which stores bile.

Stomach

Curving from underneath the liver is the stomach. The stomach is the first major site of chemical digestion. Frogs swallow their meals whole. Follow the stomach to where it turns into the small intestine. The pyloric sphincter valve regulates the exit of digested food from the stomach to the small intestine.

Small Intestine

Leading from the stomach. The first straight portion of the small intestine is called the duodenum, the curled portion is the ileum. The ileum is held together by a membrane called the mesentery. Note the blood vessels running through the mesentery, they will carry absorbed nutrients away from the intestine. Absorption of digested nutrients occurs in the small intestine.

Large Intestine

As you follow the small intestine down, it will widen into the large intestine. The large intestine is also known as the cloaca in the frog. The cloaca is the last stop before wastes, sperm, or urine exit the frog's body. (The word "cloaca" means sewer)

Esophagus

Return to the stomach and follow it upward, where it gets smaller is the beginning of the esophagus. The esophagus is the tube that leads from the frogs mouth to the stomach. Open the frogs mouth and find the esophagus, poke your probe into it and see where it leads.

Mechanism of Digestion in Digestive System of Frog

The digestive system of a frog starts with the mouth. Mouth helps in consumption of food. This process is known as ingestion. Frog feeds on flies or insects. As the teeth’s present in frog is very week they are not useful to catch the agile prey. Frogs catch their food (such as insects and flies) with the help of its stick tongue and mixes it with the saliva. The teeth’s present in the upper jaw are called the maxillary teeth, it helps in grinding the ingested food before it is swallowed.

The saliva produced and secreted by the salivary glands helps in conversion of starch to sugar and adds liquid to the ingested food.The food mixed with saliva then moves from mouth into the pharynx, and then into the oesophagus. It pushes the food further into the sac like structure stomach. This movement is food into the stomach is known as deglutition or swallowing.

Food particles in the stomach mix thoroughly with enzymes and other fluids due to contraction of smooth muscles present in the stomach. Peristaltic movement propels the food particles into the digestive tract and the pyloric sphincter valve is involved in preventing the movement of food backward from the stomach.

The food which is partially digested in stomach then proceeds in to the small intestine, where most part of the digestion occurs. It is divisible into duodenum and ileum. Pancreatic juice is secreted from the pancreas and bile through the gallbladder from the liver to the small intestine, which helps in completion of digestion.

Absorption of the digested nutrients in digestive system of a frog occurs in small intestine. Absorption unabsorbed nutrients and reabsorption of water takes place in the large intestine. Liquid wastes are in frog is passed to the urinary bladder, while solids are routed to the cloaca. Both liquid and solid wastes in frog are expelled out through cloaca which is a slit that opens out finally in digestive system of a frog.

Absorption

Digested food is absorbed by the numerous finger-like folds in the inner wall of intestine called villi and microvilli. The undigested solid waste moves into the rectum and passes out through cloaca.

Excretory System

It is represented by a pair of kidneys, a pair of ureters and a urinary bladder. Kidney contain numerous units called nephrons which filter blood, remove urea and convert it into urine. It is collected in the urinary bladder through ureters (kidney ducts), temporarily stored and then periodically eliminated.

The excretory system becomes closely associated with the reproductive system, particularly in the males. The two systems together represent the urinogenital system.

Blood Vascular System

The vascular system of frog is well-developed closed type. Frogs have a lymphatic system also. The blood vascular system involves heart, blood vessels and blood. The lymphatic system consists of lymph, lymph channels and lymph nodes.

Heart: Heart is a muscular structure situated in the upper part of the body cavity. It has three chambers, two atria and one ventricle and is covered by a membrane called pericardium. A triangular structure called sinus venosus joins the right atrium. It receives blood through the major veins called vena cava. The ventricle opens into a saclike conus arteriosus on the ventral side of the heart\

Arteries & Veins: The blood from the heart is carried to all parts of the body by the arteries (arterial system). The veins collect blood from different parts of body to the heart and form the venous system. Special venous connection between liver and intestine as well as the kidney and lower parts of the body are present in frogs. The former is called hepatic portal system and the latter is called renal portal system.

Blood: The blood is composed of plasma and cells. The blood cells are RBC (red blood cells) or erythrocytes, WBC (white blood cells) or leucocytes and platelets. RBC’s are nucleated and contain red coloured pigment namely haemoglobin. The lymph is different from blood. It lacks few proteins and RBCs. The blood carries nutrients, gases and water to the respective sites during the circulation. The circulation of blood is achieved by the pumping action of the muscular heart.

Coordination By Hormones

The chemical coordination of various organs of the body is achieved by hormones which are secreted by the endocrine glands. The prominent endocrine glands found in frog are pituitary, thyroid, parathyroid, thymus, pineal body, pancreatic islets, adrenals and gonads.

Control & Coordination

The system for control and coordination is highly evolved in the frog. It includes both neural system and endocrine glands.

Reproductive System

Frogs have well organised male and female reproductive systems.

Male Reproductive Organs: Male reproductive organs consist of a pair of yellowish ovoid testes, which are found adhered to the upper part of kidneys by a double fold of peritoneum called mesorchium. Vasa efferentia are 10-12 in number that arise from testes. They enter the kidneys on their side and open into Bidder’s canal. Finally it communicates with the urinogenital duct that comes out of the kidneys and opens into the cloaca. The cloaca is a small, median chamber that is used to pass faecal matter, urine and sperms to the exterior.

Female Reproductive Organs: The female reproductive organs include a pair of ovaries. The ovaries are situated near kidneys and there is no functional connection with kidneys. A pair of oviduct arising from the ovaries opens into the cloaca separately. A mature female can lay 2500 to 3000 ova at a time.

Fertilization: Fertilisation is external and takes place in water. Development involves a larval stage called tadpole. Tadpole undergoes metamorphosis to form the adult.

Significance for Humans: Frogs are beneficial for mankind because they eat insects and protect the crop. Frogs maintain ecological balance because these serve as an important link of food chain and food web in the ecosystem. In some countries the muscular legs of frog are used as food by man.

Muscular system

Muscle function during jumping in frogs

We determined the influence of temperature on muscle function during jumping to better understand how the frog muscular system is designed to generate a high level of mechanical power. Maximal jumping performance and the in vivo operating conditions of the semimembranosus muscle (SM), a hip extensor, were measured and related to the mechanical properties of the isolated SM in the accompanying paper [Muscle function during jumping in frogs. II.

Mechanical properties of muscle: implication for system design. Am. J. Physiol. 271 (Cell Physiol. 40): C571-C578, 1996]. Reducing temperature from 25 to 15 degrees C caused a 1.75-fold decline in peak mechanical power generation and a proportional decline in aerial jump distance. The hip and knee joint excursions were nearly the same at both temperatures.

Accordingly, sarcomeres shortened over the same range (2.4 to 1.9 microns) at both temperatures, corresponding to myofilament overlap at least 90% of maximal. At the low temperature, however, movements were made more slowly. Angular velocities were 1.2- to 1.4-fold lower, and ground contact time was increased by 1.33-fold at 15 degrees C. Average shortening velocity of the SM was only 1.2-fold lower at 15 degrees C than at 25 degrees C. The low Q10 of velocity is in agreement with that predicted for muscles shortening against an inertial load.

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How do frogs move?

It hops and stretch their long legs they hop and say kokak kokak the biochemistry the frogs movement is concealed within the legs and the hyprothermine bladder. With this structure, the frogs movement is incredible, for it propells the frog forward to incrediable heights. this astonishing fact is the secret to the frogs movement.

Why do frog jumps?

Snakes slither, fish swim, horses gallop, and frogs jump! – Although some frogs crawl or swim and a few don’t jump at all, the majority of frogs use their nice, strong back legs to jump around.

One reason that jumping is helpful to frogs is that it helps them to get away quickly from any animal who thinks the frog would make a good lunch; some frogs can jump as much as 20 times the length of their own body in just one hop! They also often jump in a zigzag pattern, which makes escaping even easier -- all of the zigzagging leaves the other animal pretty confused.

Many frogs also choose jumping because they’re built so well for it! With long, strong back legs for bouncing up off the ground, and a short body to give them a softer landing, frogs are natural hoppers.

Why do frogs croak?

Ribbit, ribbit! If you’ve ever spent some time near a frog-filled pond, then you already know that familiar sound is the call of a frog.

The answer is that most frogs who croak are male frogs, and they do it as a mating call to attract female frogs! In a frog’s world, that ribbiting sound is very appealing! Croaking is also sometimes used to declare territory and tell other frogs to stay away.

Some kinds of frogs have a special bubble-looking body part that helps them make their croaking sound. Scientists have found that different types of frogs make different types of croaking sounds. It all depends on the size of the frog and its species.

What does frog eats?

Baby frogs eat mostly algae, mosquitoes, flies, and other flying bugs. It will eat the same things that a grown frog would eat will also eat. They would eat slower smaller fish if they were bigger.

Frogs eat insects such as flies, grasshoppers, crickets, etc. Larger frogs will even eat small animals such as fish, mice and bats. Frogs prefer their food to be alive when they catch it and will not eat anything that is dead.

There are many animals that eat frogs including humans. Some people eat from legs from a bullfrog. I like them myself. Other animals are snakes, birds, dogs, and some fish.

The frogs eat worms, insects, and food like lettuce. The snails and slugs are there favorite thing the frogs like eating as a dessert.

How does frog breathe?

Frogs are amazing creatures because they breathe through their skin and they also breathe through their lungs. When they are under water they breathe through their skin and on land they use their lungs.

Frogs and toads breathe through their skin when they are underwater or buried under dirt during hibernation, but they have lungs to breathe with when they are just hopping around on the ground.

Frogs have thin skin which oxygen can easily pass through allowing them to breathe underwater. They also have lungs so they can breathe on land.

How far frog can jump?

That depends on the frog and what is chasing it. Most frogs can jump about 15 times their body length. Frogs jump to avoid danger and it would depend on the size and strength of the species

What is the breathing organ of frogs?

Frog can be classified having gills and lungs tadpoles have gills while frogs[or adult]have lungs.

How does frog breathe underwater?

They don't. Frogs can hold their breath for a very long time but they still have to come to the surface to breath air. They don't, they hold their breath like we do, and they can just do it a long time.

What is the movement of the hind legs when the frog swims?

The hind legs are straight and together and the frog pushes it's hind legs apart and sort of bends it as well to swim through the water.

Frog feet?

Feet For Climbing

Tree frogs, like this White-lipped Treefrog (Litoria infrafrenata), have sucker-like adhesive disks, or Sticky pads, which aid in climbing, on the tips of the fingers and toes.

Feet for Swimming

Aquatic Frogs like the African Dwarf Frog, and the African Clawed Frog, have webbing between their toes that aid in swimming. You can test how much this helps by the following little experiment

First, try spreading your fingers and running them through a tub of water.

Now, get a plastic sandwich bag and place it over your hand.

Spread your fingers and NOW try running it through the water. This adds a lot of swimming power!

Feet for Digging

Frogs that burrow into the sand to keep moist in the heat have stubby clawlike fingers that are adapted to digging.

Feet for Flying

Some frogs in the Rhacophorus species, such as R. reinwardtii and R. nigropalmus, have parachute-like webbing on their hands and feet which act as an air-brake when they glide from tree to tree or leaf to leaf. These frogs are known as "Flying Frogs."

Habitat

Frogs are amphibians, which means they typically live on land but breed underwater. So, what is the habitat of a frog? Frogs habitats are generally near a water body; this article will describe to you the natural frogs habitats, the commercial frog aquarium habitat, and will guide you on how to make your garden into a favorable frog habitat.

There are over 5,000 species of frogs. One of the groups of frogs are the poison dart frogs, which are toxic and have interesting and vibrant color patterns on their bodies. There is another species called green tree frogs, which are translucent green in color and if you see their belly down on a piece of glass, you can watch the internal organs and the heart of the frog! The huge range of this species can be found all over the world, and there are different frog habitats but frogs are generally seen near semi-aquatic lands.

Frog Habitat Requirements

So what all are the frogs needs, which need to be present in a habitat to make it a favorable place for the frogs to live in? Here, is information on frog

food and habitats.

Besides water, frogs require a habitat which provides them food and shelter.

Like other amphibians, frog's life cycle consists of four stages which are the egg, tadpole, metamorphosis and the adult stage. The tadpoles need small

plants to eat, and big plants provide good shelter to hide.

These amphibians spend a lot of time in the water, they hide from danger or predators inside the water. Frogs also hunt for food, and lay their eggs in

water.

The ideal conditions for a frog habitat should have the right temperature for the eggs to hatch. An ideal frog habitat should also not have fast-moving

water, and lots of rocks and stems should be present where the frogs can lay their eggs.

Natural Frog Habitat

Frogs are seen almost everywhere, they exist in rain-forests, forests and caves; they can also be seen in deserts and on mountaintops.

The best places for frogs are places which are mucky and have lot of bugs. An interesting fact about frogs is that they have an extensible tongue which

has a sticky surface, and they can flick it quickly to catch a bug when it is resting on a leaf or flying.

Frogs are mostly seen in swamps, marshes, ditches, streams and puddles, as these places have plenty of muck and insects.

Frogs lay eggs which hatch into tadpoles, the tadpoles are dark squiggly looking creatures who have tails for swimming and gills for breathing, as they

spend their time living in water.

After the stage of metamorphosis, the tadpole transforms into the four-legged frog. Frogs spend most of their time on the land, but are mostly around

some or the other water body. Frogs breathe and drink from their skin, and thus their skin is always wet.

Frogs form an important part of the ecological system as they feed on bugs, and are food of many predators like birds. However, due to the chemical

pollution and the destruction of wetlands for construction purposes, there is a huge decline in the amount of frogs habitat.

Creating a Frog Habitat

Children can buy the commercial aquarium, which are designed especially for frogs. These frog habitats or aquariums have interesting inbuilt

materials. All one needs to do is catch a frog and release it in this aquarium, and one can have frogs as pets.

Adults can create an environment for the frogs, or transform a section of their garden into a frog habitat. With the above mentioned needs of the

frogs, one will need to take care of other things too, to create and maintain a frog pond. Dig a pond and make sure the location is part-shaded and

part-sunny, but not under a tree. The pond in the center should have 50 cm depth and the edges should be shallow and have a flat base. Cover the

base with gravel, and place rocks, logs and plants in and around the pond, and release some frogs in this pond. This way you will have your very own,

frog habitat in your garden and watch the life cycle of the frogs.

This was all about the natural frog habitat facts and building a frog habitat. You can buy a commercial frog aquarium for the kids or build all by

yourself a frog habitat, and by creating the frog habitat you will be, in a way, helping the environment

Locomotion

The frog's powerful hind legs are adapted for both swimming and leaping. The strong extensor muscles of the thigh contract, extending the limb and thrusting the foot against the ground or against the water. The thrust is transmitted through the body of the frog by the pelvic girdle and the spine so that the whole animal is pushed forward. In the water the webbed hind feet provide a greater surface area for pushing backwards on the water. The smaller fore-limbs help to steer when the frog is swimming and absorb the shock of landing after a jump on land. On moving from water to land or over rough ground the frog will crawl rather than leap.

Breathing

The frog's skin is smooth and moist, fairly thin, and well supplied with blood vessels which branch into a fine network of thin-walled capillaries. Oxygen from the air or water, dissolves in the film of moisture over the skin, diffuses through the skin, through the walls of the blood capillaries and into the blood. Here it combines with the red pigment, haemoglobin, and is carried away in the circulation, back to the heart and then round the rest of the body. Excess carbon dioxide is eliminated from the blood in a similar way, diffusing out of the blood vessels, through the skin and into the atmosphere. The skin is effective for breathing on land or in water and is in use continuously.

When the frog is inactive the skin absorbs enough oxygen to meet its needs. During and after activity it may breathe air into its lungs by gulping movements of the floor of its mouth. The lungs can be used only when the frog is on land or swimming at the surface. The nostrils have valves which prevent the entry of water and control the flow of air into the lungs. Unlike the mammals, amphibia and reptiles do not make regular and rhythmic breathing movements but gulp air into their lungs spasmodically as the need arises. Air is forced into the lungs by raising the floor of the mouth. The lungs lie in the body cavity and, unlike those of mammals, are not separated from the other organs by a diaphragm. The lungs can be inflated to

many times their relaxed size, so apparently inflating the entire frog. The moist lining of the large mouth is also a respiratory surface. Like the skin, it is in constant use, except when submerged, but the movements of the mouth-floor can be used to exchange the air in it.

Feeding

Adult frogs are carnivorous, feeding on worms, beetles, flies and other insects. Worms and beetles may simply be picked up by the mouth but flying insects can be caught on the wing. On occasions the frog will leap towards the insect and trap it in its wide, gaping mouth; on other occasions its tongue is used. The tongue is attached to the front of the mouth and can be rapidly extended by muscles. It is shot out in a half circle, and the insect is trapped by the sticky saliva covering the surface. Insects can be picked off the ground or vegetation in a similar way. The prey is swallowed whole but there are rows of tiny, closely set teeth in the upper jaw and in the roof of the mouth which prevent the prey escaping. In swallowing, the eyes are often pulled farther into the head and press down on the prey.

Hibernation

Winter is a serious problem in the world of frogs and turtles. So is a very hot dry summer, Like snakes, these cold-blooded animals have little or no

ability to keep warmer or cooler than their surroundings; their body temperatures rise and fall with those of the places where they are. Few, if any,

can endure long exposure to more than a degree or two below 32 F, nor survive more than an hour at, say, 100 F. We are often asked, "What do they

do in winter? How do they keep alive?

They hide and hibernate. Those that live in water hide away beneath the ice of lakes, ponds and streams; those that live on land burrow under leaf

litter and soil below the frost line. They become very sluggish and torpid. They do not eat and all life processes drop to a very low ebb. They "sleep".

In times of summer drought and intense heat, when ponds dry up, some kinds of frogs and turtles dig in the soil or creep under logs and rocks for

protection from the burning sun and to conserve their body moisture. Then they, too, become torpid. This is called estivation. During the extreme

drought of 1934, while deepening a pond which had gone dry, one of our senior naturalists found a large snapping turtle beneath three feet of soft

earth but alive.

All frogs and turtles breathe with lungs, at least from spring until late autumn, just like people. We can see them inhale and exhale when basking in

the sun -- faster on warm days, slower when it is cool. You may wonder what they do for oxygen when imprisoned beneath the ice, often for months

at a time. The answer is that their bodily fire, called metabolism, burns lower and lower as winter sets in, until it is literally reduced to a mere spark of

life. Their hearts beat at long intervals and they crawl or swim, if at all, in slow motion. Very little oxygen is needed but that little is a matter of life or

death. They get it from oxygen dissolved in the water: not like fish, through gills, but, in the case of turtles, through the linings of their mouths and

throats; or perhaps, as in the case of frogs, through their skins.

Diet/Food

Most frogs eat mainly plants when they are tadpoles and switch to a diet of mainly insects once they turn into froglets. Some tadpoles also eat little

bits of dead animal matter that float down to the bottom of the water, and the tadpoles of a few species will even eat an insect or other invertebrate

(in-VER-teh-breht), which is an animal without a backbone.

Not all adult frogs will only eat insects. Many of the larger species will gulp down anything they can catch and swallow. Bullfrogs, which are common

throughout much of North America, are one type of frog that will almost eat anything that comes within reach, including ducklings and other

bullfrogs.

Conservation

Sub-fossil records indicate there were at least seven species of native frogs in New Zealand before the arrival of people approximately1000 years ago.

Habitat change and the introduction of non-native mammals have caused the three largest frog species to become extinct. The remaining four New

Zealand frog species all have severely reduced distributions and populations sizes.

Archey’s frog - Critically Endangered

Sub-fossil records and the two remaining disjoint populations (Coromandel Peninsula and Whareorino)

suggest the mainland range of this species was once more widespread. A sharp population decline was

detected in the late 1990’s and this species is now in critical danger of extinction.

Hamilton’s frog - Critically Endangered

One of the world’s rarest frogs with an estimated population of less than 350 individuals. These frogs survived

only in a small rocky area on mammal-free Stephens Island in the Cook Strait. Sub-fossil indicate Hamilton’s

frog was once widely distributed throughout the lower North Island and upper South Island.

Maud Island frog - Endangered

Also restricted to a single island in the Marlborough Sounds following the arrival of humans in New Zealand. An estimated 40 000 frogs survive in a

remnant of regenerating forest on rodent-free Maud Island.

Hochstetter’s frog - Vulnerable

Ten populations of this species are known in the upper half of the North Island. The fragmented distribution

of these populations suggests the distribution of this species has become reduced following the arrival of

humans.

Conservation Threats

The four remaining species of native frogs in New Zealand face a number of threats:

Non-native mammals

Anecdotal evidence suggests predation and/or competition with non-native mammals may be partially responsible for historical declines of the four

extant native frog species. The distribution of frogs on the mainland became restricted following the arrival of non-native mammals and two frog

species now survive only on mammal-free island refuges.

While there is a lack of direct evidence to evaluate the exact nature of the effect of non-native mammals on native frogs, ship rats (Rattus rattus) have

been documented predating upon Hochstetter’s and Archey’s frogs in North Island forests. Non-native mammals such as pigs and goats can cause

severe disturbance and degradation of habitat which may also affect native frogs.

Habitat change

Historical declines may also be partially attributed to the destruction of forest habitats that followed the arrival of Polynesian and European settlers.

Today, Hochstetter’s frog continues to be threatened by localised destruction of stream habitat that occurs as a result of mining, forestry and farming

practices.

Disease

A chytrid fungus (Batrachochytrium dendrobatidis) has been implicated in the worldwide decline of numerous

amphibian species. Frogs infected with this fungus suffer chytridiomycosis, a disease affects amphibian skin

and is often fatal. Chytrid zoospores can survive in damp conditions and may be transported between frog

populations in muddy clothing and footwear.

This disease was first detected in New Zealand in 1999 in an exotic frog population in Canterbury. It has since

been identified in all populations of Archey’s frog in the upper North Island. As a result of infection, one

population of Archey’s frog on the Coromandel Peninsula has declined in numbers by over 80% resulting in a

‘Critically Endangered’ listing from the IUCN.

Conservation Action

Translocations

Translocation is a tool used to improve the conservation status of a species. It is the deliberate movement of animals to an area in which they have

become locally extinct. All translocations require careful planning to ensure the factors that caused the original population to become locally extinct

have been removed or controlled. Translocations also require long term planning and monitoring to assess the outcome and to determine the factors

that have influenced success or failure.

Translocations may occur for a number of reasons. While restricted to single locations, Hamilton’s frog and

Maud Island frogs were vulnerable to extinction from a stochastic event (fire, disease or invasion by a non-

native mammal species). Translocation has been used to mitigate such threats, beginning in 1985 with the

intra-island translocation of 100 Maud Island frogs to suitable habitat 500 m away from their original

location. In 1997, 300 Maud Island frogs were translocated to a mammal-free island in the Marlborough

Sounds. Following the success of this translocation a further 101 frogs were moved to a second island in

2005. Monitoring of all three populations continues today.

Hamilton’s frog was especially vulnerable to extinction with such a small population in a confined area of Stephens Island. The Department of

Conservation initially translocated 12 frogs to specially constructed habitat also on Stephens Island. Recently 70 Hamilton’s frog were also

translocated to one of the Chetwode Islands in the Cook Strait.

Translocation can also be used to re-introduce a species to an area in which it has become locally extinct to fulfill objectives of restoration projects.

In 2006, 60 Maud Island frogs were translocated to Karori Wildlife Sanctuary. Karori Wildlife Sanctuary is a 252 ha restoration project 2 km from

Welllington City and is surrounded by an 8.6 km fence that excludes all introduced species of mammals except mice. This translocation is significant

because it is the first translocation of a native frog back to the mainland and provides a number of unique research opportunities to gain knowledge

on how mice may affect native frog populations.

Disease management

The Department of Conservation and frog researchers are working hard to reduce the threat of infection by preventing the spread of chytrid fungus.

All people visiting areas with frog populations adhere to strict hygiene protocols including not taking packs, bags or gaiters into frog areas, and

treating clothing, footwear and research equipment with a biocide known to kill the fungus.

Control of Predators

The Department of Conservation runs an active predator control programme (more information on this topic will be coming shortly). Check out the

Commericail frog farming

Raising and selling frogs on a commercial basis has not proven to be successful economically in Virginia or elsewhere in the United States to our

knowledge. Although farming for frog legs sounds promising, operating a profitable frog farm seems to be more of a myth than a reality. Those few

individuals who claim to be successful frog farmers generally are distributors engaged in the selling of adult frogs, tadpoles, or frog eggs, frequently

harvested from the wild.

Many "frog farms" turn out to be natural marshy areas, swamps or shallow ponds with abundant food and habitat suitable to the needs of wild frogs.

At some frog farms, culture methods simply consist of increasing the shoreline area, erecting a fence to exclude predators and retain the frogs, and

stocking wild frog eggs or tadpoles. The frogs usually are left to raise themselves.

Intensive indoor frog culture techniques have been developed for the production of laboratory frogs used in medical and biological research. At

present, however, it is doubtful that these indoor culture techniques can be applied economically to the culture of large frogs for human

consumption.

Edible Frogs

A number of species of frogs, including the green frog (Rana clamitans), the leopard frog (Rana pipiens), and the pickerel frog (Rana palustris), are

harvested from the wild and sold as a luxury food - frog legs - in expensive restaurants. However, the bullfrog (Rana catesbeiana) has the greatest

potential for culture.

The common bullfrog, often referred to as the "Giant Frog" or "Jumbo Frog," is the largest native North American species, often reaching 8 inches in

body length. Because of its large size, the bullfrog is the most preferred and commonly attempted species for farming.

Breeding and the Life Cycle

Bullfrogs lay their eggs in shallow standing water during the Spring (April and May) in temperate climates. The large, floating, jelly-like egg mass

produced by a single female may cover an area about 3-5 feet square and include from 10,000 - 25,000 individual eggs. The eggs hatch in 1 - 3 weeks,

depending on the water temperature, into larval frogs that commonly are called tadpoles. Bullfrog tadpoles chiefly are vegetarians, spending most of

their time grazing on microscopic plants and bottom algae.

Slow Growth

Frogs and other amphibians are coldblooded animals that grow slowly, not a particularly desirable trait for farming. The rate of growth of the bullfrog

tadpole varies with the climate, length of the growing season, and available food supply. Even in temperate climates, it may take a year or more to

transform the tadpole into a young bullfrog. Another year or more is required to produce a mature, marketable-size bullfrog. Therefore, in the mid-

latitude states like Virginia, development from egg to a mature bullfrog of harvestable size may take over 3 years, even under ideal conditions.

Artificial Feeding

Feeding is the critical process in culturing frogs successfully. Poorly fed frogs are susceptible to disease and frequently resort to cannibalism (eating

younger bullfrogs and tadpoles), thereby reducing the harvestable population. Frogs and tadpoles reared outdoors will obtain some natural foods, but

for intensive commercial culture of frogs in high densities, supplemental food must be supplied.

Bullfrog tadpoles are mainly vegetarians and will consume most soft plant matter and some animal feed. Acceptable tadpole foods include such items

as boiled potatoes, meat scraps, or chicken viscera. Recycling butchered frog scraps is a convenient way to reduce food costs, but may transmit

disease.

Once the tadpole has metamorphosed into the adult frog (i.e., the legs are fully developed and the tail is absorbed), feeding becomes especially

difficult. Adult frogs feed exclusively on moving animals, primarily small insects. They generally refuse to eat dead or at least non-moving food.

Japanese researchers reportedly have been able to induce frogs to eat dead silkworm pupae by using small motorized trays that mechanically roll the

silkworms back and forth to simulate live animal motions.

Live animals, such as minnows, crayfish, and insects, also are placed in these trays to condition the frogs to feeding from these mobile platforms.

Although this technique may work, most American frog farmers rely on stocking or attracting live food animals. Smaller species of frogs, tadpoles,

crayfish, and minnows can be stocked as food items for bullfrogs although the expense of live feed is high.

The use of strong flood lights to illuminate the shoreline at night will attract flying insects and provide additional food for frogs. However, this

technique is not sufficient to supply enough food to sustain the high frog densities needed for a commercial operation. At present, live food, adequate

in quantity and quality, remains the greatest problem for would-be frog producers.

Pond Design

A mature bullfrog may require as much as 21 feet of shoreline as its exclusive feeding territory. Territorial behavior firmly limits the number of frogs

that can coexist in a small area. Available shoreline area (the ratio of land to water edge) is a critical factor. The total size of the pond is not as

important as shoreline, because frogs use shallow shorelands to rest and feed. Large expanses of deep, open water are seldom used by frogs.

Regularly shaped round or square ponds have less shoreline in proportion to area than small irregular-shaped ponds. Therefore, increasing the length

and irregularity of the shoreline by constructing long narrow ponds with numerous islands, shallow bays, or coves will increase the carrying capacity of

frogs in a given area. Some growers increase the amount of shoreline, by constructing ponds as a series of narrow ditches.

Ponds should be deep enough to protect the adult frogs and tadpoles from extremely hot or cold temperatures. Accordingly, the depth of the pond

must vary with the climate. In the southern U.S., water from 1-2 feet deep is adequate, but in the North, much deeper water (6-12 feet) may be

required to assure the over-winter survival of frogs hibernating in the bottom muds. Most of the pond should be shallow (2 -12 inches deep), because

frogs normally rest and feed in shallow waters.

Predatory fish, snakes, snapping turtles, cats, foxes, and water birds that feed on adult frogs and tadpoles should be fenced out. Enclose the pond

with a mesh fence about 3 feet high. A vertical fence, topped with wings, one inclined outward and the other inward, will exclude predators and keep

frogs in. Birds are especially difficult to exclude, but, in small ponds, a wire net stretched above the shallow shoreline area may offer some protection.

Some loss due to predatory animals should be expected.

Water Quality and Quantity

An abundant supply of high quality water must be readily available to the frogs throughout the growing season. For good growth, water temperature

should remain relatively constant at 20° to 26° C. The pH of the water should be slightly acidic. Dissolved oxygen always should be present because

tadpoles, as fish, breathe by gills and are dependent on the available oxygen. Pesticides and other dangerous chemicals often are toxic to frogs, and

even non-lethal concentrations could restrict the sale of frog legs for human consumption. Pesticides can be distributed widely by winds and water

currents. However, with care and intelligent site selection, most pollution problems can be avoided.

Geographic Limits

In aquaculture (farming aquatic animals), successful results seldom are transferable from one geographic region of the country to another. Climate

often limits aquacultural enterprises. The growing season for frogs is longer in tropical than temperate climates, therefore the potential for frog

farming may be better in South America or Louisiana than in Virginia or other temperate climate states. Clearly, outdoor frog farming in the Northern

states would not be advisable.

Other important variables to consider are the lower labor costs, greater water availability, and the high demand in Southern states where frogs,

crayfish, catfish, and other aquatic animals are traditional foods.

Harvesting

Techniques for collecting and harvesting pond-cultured bullfrogs are the same as those used in capturing wild frogs. These methods include nets,

hand capture, spearing, and fishing with a hook and line. Hooks baited with live insects, earthworms, or artificial lures (a piece of red cloth or yarn) are

dangled in front of the frog. Spearing and band capture techniques are done most effectively at night, using a bright spotlight to momentarily daze

and immobilize the frog. Obviously, new methods to efficiently harvest large numbers of frogs need to be developed.

Diseases

The most common disease of frogs, red-leg disease, is due to a bacterial infection (Aeromonas), often resulting from overcrowded conditions. The

best preventative methods are adequate nutrition and space. Infected individuals should be isolated immediately, and treated with antibiotics. In

severe cases, it may be necessary to drain the ponds and allow them to dry out for several weeks.

Economic Factors

Good management and operational skills are critical to an aquaculture enterprise. The success of aquatic farming depends largely on the cost to grow

and market for the product. Before attempting to raise frogs or any other aquatic crop, the prospective culturist should conduct a survey of the local

or regional markets to determine the current supply, present and expected demand, price elasticity, extent of competition, and other socioeconomic

factors.

Large numbers of wild frogs imported into the United States or captured locally and sold at low prices will reduce the potential profitability of frog

farming. Market price fluctuations of frog legs are volatile. Prospective frog farmers realistically should assess their own financial status because most

aquaculture enterprises require a high initial investment, have a number of associated "hidden" costs, and produce low realized return on short term

investments. Expectations of large or easy profits are extremely unrealistic.

As in agriculture, aquatic farming a risky business. A number of unpredictable and uncontrollable catastrophes include prolonged droughts, severe

floods, toxic chemicals, intense predation, infectious diseases, and contagious parasites literally can destroy an entire year's crop overnight.

Prospective frog farmers should be well aware of these and other associated risks and be prepared to sustain some periodic losses.

Future Potential

At present, there is no well-established frog farming industry in the United States. Current practices and past efforts at commercial frog farming have

been unsuccessful largely because of physical, chemical, biological, and economic constraints. Opinions concerning the feasibility of frog farming in

Virginia range from the optimistic to those that maintain it is not possible economically.

Considering the current state of the art, frog farming as a commercial venture appears to have severely limited potential. However, as intensive

hunting and increased drainage of natural wetlands continue to reduce the wild frog populations, the demand for frogs may reach a critical point,

permitting skilled culturists to profitably farm frogs.

Declining Wild Amphibian Populations

Wild populations of frogs, toads, salamanders and other amphibians are declining throughout the world. Scientists suspect greater atmospheric ozone

and the increased incidence of ultraviolet radiation, acid rain, and other forms of environmental pollution, but the exact causes for the rapid

disappearance of frogs and other amphibians are unknown. Researchers fear extinction of many species of amphibians worldwide. This decline will

reduce the supply of wild frogs for food and for farming operations. It also may impose new regulations and restrictions on frog farming enterprises.

In Virginia and most other states, it is lawful to capture and possess no more than a few wild native or naturalized amphibians for private use and not

for sale. A permit for capturing, holding, propagating, and selling of wildlife, including amphibians, is required in most states.

Economic aspects of frog farming

Social benefits

The outcome will be the best design and application of wildlife ponds to maximise individual participation, community involvement and biodiversity

benefit, particularly for frogs, and a better informed community armed with confidence and the knowledge to act.

Guidelines on best environmental design and use of wildlife ponds for frogs.

Community involvement through landowner participation in installing wildlife ponds and through reporting frog populations on their farms.

Local learning opportunities through public talks, school groups, seminars, written publications and field days based on the knowledge generated by

the project.

Regionally relevant knowledge that will help to maintain and enhance frog populations.

A better informed community able to implement sound environmentally sustainable on-farm practices.

Economic benefits

The installation of wildlife ponds in farm woodlands in the Wimmera and Mallee is a cost effective and water efficient method of enhancing

biodiversity values on farms. This project will determine the best approach to conserve frog populations that are efficient in terms of farming

resources, cost and water usage.

The establishment of a wildlife pond in a woodland will lead to improved sustainable farming through the ecosystem services that these

environmental asset provides. Environmental, or natural assets, include soil, plants and animals, water and air. These assets provide inputs into

production through the conservation of soil health and moisture, moderation of paddock climate, salinity control, pest control and firewood. They

also provide a focus on the values that people discern from nature, including recreational, spiritual, and aesthetic value.

Environmental benefits

Farm dams, the ‘wetlands’ on farms, are (or were) the stronghold of frog populations in woodlands and are the sites of greatest biodiversity value. In

the region serviced by the Northern Mallee Pipeline, farm dams dried out after decommissioning of the channel network and now lie idle. Prolonged

drought and a lack of water in storage resulted in no water being released down the Wimmera channel system in 2006, and consequently no filling of

farm dams. Water conservation and wise use is thus becoming a critically important factor in the region both for farming and local community needs.

The Diversity in a Piped System project (DIPS) has demonstrated that the installation of a wildlife water point in a farm woodland can increase the

biodiversity value of the woodland, and that the absence of open water in the Wimmera and Mallee has serious consequences for frog populations.

Frogs eat a wide range of insects, and because they susceptible to pollution, are good indicators of landscape health. Frogs are not only a useful form

of pest control but monitoring frogs can also help assess the environmental impacts of land management practices.

Frogs are important in medical research that benefits humans

Frogs produce a wide array of skin secretions, many of which have significant potential to improve human health through their use as

pharmaceuticals. Approximately 10% of Nobel Prizes in Physiology and Medicine have resulted from investigations that used frogs. When a frog

species disappears, so does any promise it holds for improving human health.

Doctor Frog to the Rescue

Scientists are finding new ways to treat sick people by studying frogs.

This is yet another good reason to be concerned about the fate of our world’s frogs since every day so many frogs are

threatened by environmental problems.

For example, scientists found a way to make a new drug painkiller from the toxins in a frog's skin. The frog (Epibpedobates

tricolor) is found in Ecuador. Poison in its skin protects it from predators. They couldn't use the poison itself for humans because

it's too powerful (isn't that amazing?), but researchers took the frog poison (its structure) as a model for this new drug.

Habitat loss

One of the most pressing threats to frogs today is the chytrid fungus, a deadly skin fungus that has moved across the globe causing amphibian

declines in Australia, South America, North America, Central America, New Zealand, Europe, and Africa killing frogs by the millions. The chytrid fungus

is responsible for over 100 frog and other amphibian species extinctions since the 1970’s. Chytrid fungus has been detected on at least 285 species of

amphibians (including frogs) from 36 countries.

Climate change is also having an impact on frogs that live on mountain tops. They are being hit hard since they are dependant on moist leaf litter

found in cloud forests as a suitable place to lay their eggs. As temperatures increase further up mountain sides, clouds are being pushed further away

and leaves are drying out leaving less suitable habitat for frogs to lay their eggs. As frogs migrate further up the mountain they are faced with the

inevitable problem that once they reach the top, unlike birds, they can go no further.

Frogs are also facing many threats from many different environmental factors: pollution, infectious diseases, habitat loss, invasive species, climate

change, and over-harvesting for the pet and food trades are all contributing to the rapid rise of frog extinctions since 1980.

Reasons for Hope

Chytrid fungus has been recognized as one of the largest threats to amphibian populations around the world. In 2009 a group of organizations came

together to respond to the crisis. Defenders of Wildlife (Washington DC), Africam Safari Park (Mexico), Cheyenne Mountain Zoo (Colorado), the

Smithsonian National Zoological Park (Washington DC), the Smithsonian Tropical Research Institute (Panama), Zoo New England (Massachusetts) and

Houston Zoo (Texas) have launched the Panama Amphibian Rescue and Conservation Project.There are yet undiscovered species of frogs in the world.

A new species of flying frog was discovered in the Himalayan Mountains in 2008.

Pollution & pesticides

Pesticides (insecticides, fungicides, herbicides, etc...) are toxic chemicals that generally undergo little to no testing on amphibians prior to their being

approved for use. Unfortunately, the law of gravity has it that many of these pesticides end up in waterways, where amphibians live and breed.

Amphibians have permeable skin that is highly absorbent, making them extremely susceptible to pollutants and pesticides

An abundance of scientific literature has demonstrated the negative effects of an array of commonly used pesticides on amphibians: delayed

metamorphosis, immunosuppresion, hermaphroditism, sex reversal, and outright mortality. There are over 18,000 registered pesticides in the USA.

According to the Center for Biological Diversity, 200 million pounds of pesticides are applied each year in California alone, and two billion pounds

throughout the USA annually.

Many pesticides are applied by spraying, and a portion of the chemicals inevitably get caught in the wind and lifted up to the clouds, where they can

be carried for hundreds of kilometers from their source -- often getting deposited on mountaintops in once pristine national parks and preserves

Populations of the critically endangered mountain yellow-legged frogRana muscosa that live downwind of highly agricultural areas in California's

Central Valley have disappeared at a significantly higher rate than other populations, and the species is on the verge of extinction.

Roundup

Roundup (also sold as Touchdown Total) is lethal to gray treefrog and leopard frog tadpoles, and most likely a host of other as yet untested frog

species. Roundup is one of the most commonly applied herbicides in the USA; it's produced by Monsanto, the same folks who gave us Agent Orange.

Over half of the DNA found in frogs is also found in humans, so if these pesticides kill frogs, imagine what they do to us! Is Roundup even good for

crops? A team of USDA researchersreported that glyphosate (the active ingredient in Roundup) may actually be causing fungal root disease in

"Roundup-ready" corn and soybeans. Glyphosate is used worldwide, as can be seen on this billboard photographed in downtown Kumasi, Ghana.

Health Canada, the Federal department responsible for helping Canadians maintain and improve their health, was ordered in November 2011 to

examine the effect of Roundup on amphibians.

Chlorothalonil

Chlorothalonil is the most commonly used synthetic fungicide in the USA, commonly applied to peanuts, tomatoes and potatoes. It is also extremely

common in Costa Rica and tropical nations, where it is used on bananas and other crops. At concentrations commonly found in areas where the

fungicide is applied, Chlorothalonil causes 100% mortality to tadpoles of Cuban Treefrogs (Osteopilus septentrionalis), Squirrel Treefrogs (Hyla

squirella) and Green Treefrogs (Hyla cinerea) within 24 hours of exposure.

Predators

Frogs have many predators. Animal predators include birds, fish and reptiles.

Most rainforest frogs have pads of sticky hairs on their fingers and toes, as well as, loose sticky skin on their bellies, that make them great climbers to escape their predators. Many of these frogs live in high trees for safety.

Other frogs are very good at camouflaging themselves so that they blend in with their environment, making it harder for their enemies to find them. A frog can change the color of its skin depending on its surroundings.

Humans have become a major danger for amphibians of all types. Water pollution is causing many deformities in frogs as well as poisoning them, and loss of habitat through the building of roads and houses. In some countries, frog’s legs are considered a delicacy, which means that people love to eat them.

Infectious disease

Chytridiomycosis

In terms of its effect on biodiversity, chytridiomycosis is quite possibly the worst disease in recorded history. First identified in 1998, this potentially lethal

skin disease is caused by the chytrid fungus Batrachochytrium dendrobatidis, which has been detected on at least 287 species of amphibians from 36

countries. Chytridiomycosis has caused amphibian population declines in Australia, South America, North America, Central America, New Zealand, Europe,

and Africa, and is likely responsible for over 100 species extinctions since the 1970's.

Lacey Act

The US Fish & Wildlife Service recently solicited comments on its proposal to list amphibians as injurious wildlife UNLESS certified free of chytrid fungus. The

proposal, if successful, will significantly reduce the spread of chytrid fungus via a reduction in the intercontinental trade of amphibians for use as pets and

food.

How the chytrid fungus spreads

Humans ship millions of amphibians around the world each year. When an infected frog arrives in a new location, its disease can spread to native

populationsif it escapes captivity, it is intentionally set free, or water from its holding tank is released into the environment. Native amphibian populations

generally have no evolved defenses against the new pathogen, and an epidemic that results in population decline or extinction can occur.

The largely unregulated pet and food trades are the two most common sources of disease introduction into naïve amphibian populations. For instance, the

skin disease chytridiomycosis has been detected in Mexican axolotls Ambystoma mexicanum in Australian pet shops, and in American bullfrogs Lithobates

catesbeiana being farmed for international trade in Uruguay. Infected frogs are also unintentionally exported internationally via the zoo trade and laboratory

animal trade. Recommended reading: "Minimising exposure of amphibians to pathogens during field studies" by Philott et al (2011).

Effect of chytridiomycosis on infected frogs

Dead and dying frogs generally have disorders of the epidermis, and often exhibit behavioral changes such as lethargy and loss of righting reflex. Chytrid

zoosporangia live in the heavily keratinized stratum corneum and stratum granulosum of the frogs’ pelvic patch, digits, and ventral body, and in the

keratinized mouthparts of tadpoles. Associated epidermal changes included irregular cell loss, hyperkeratosis, and excessive sloughing of the skin. Infected

frogs begin to die roughly 21 days post-infection, and though larvae are susceptible to infection, deaths are generally restricted to metamorphosed

individuals (this is because larvae do not have much keratin). Though chytridiomycosis is unlikely to cause larval mortality, it can significantly decrease body

mass at metamorphosis and increase the duration of the larval period, both of which are likely to negatively affect the amphibian's survivorship in the long

run. Two leading hypotheses have been put forward to explain how Batrachochytrium dendrobatidis directly kills its host: 1) toxic, proteolytic enzymes are

released by the fungus, and 2) loss of electrolytes negatively affects osmoregulation and/or oxygen uptake, two primary functions of amphibian skin.

Post-metamorphic death syndrome

Chytridiomycosis-related declines are typified by “post-metamorphic death syndrome”, in which large numbers of metamorphosed individuals are found

dead or dying (or not found at all), while tadpoles and embryos still survive at the site in normal numbers. This is to be expected: B. dendrobatidis is

keratinophilic, and thus is absent in embryos (which lack keratin) and is generally restricted to the mouthparts of larvae, which until the latter stages of their

development are the only keratinized areas of their body. Upon metamorphosis, the keratinized layer begins to cover the entire body, and infection can

become lethal, potentially resulting in population decline and local extinction.

Is there a cure for chytridiomycosis?

While methods exist for curing laboratory animals infected with Batrachochytrium dendrobatidis, it is not currently possible to eradicate the fungus from

wild amphibian populations. Nor is it possible to protect a natural wilderness area prior to the arrival of the chytrid fungus. It is thus of vast importance that

the spread of the fungus due to human activities be halted. This will require international cooperation, as countries will need to implement stringent

quarantine procedures and diagnostic testing, and severely restrict the transportation of amphibians. We recommend that you do not purchase amphibians

unless you are certain they were (1) captive-bred in disease-free conditions and (2) raised locally. If you cannot confirm both of these things, you may be

inadvertently contributing to the spread of diseases to native, susceptible populations. Currently, there are very few pet dealers that provide thorough

disease testing of their amphibians, as the price is generally prohibitive.

How can you diagnose chytridiomycosis?

A correct diagnosis generally requires laboratory testing by an experienced pathologist because many infected frogs show no clinical symptoms of infection,

and conversely many sick frogs have illnesses other than chytridiomycosis. There are no symptoms that necessarily implicate chytridiomycosis is the culprit.

The most reliable methods for diagnosis are quantitative polymerase chain reaction and histology.

Over-harvesting for frog legs

The global market for frog legs and for pet frogs and salamanders is extensive. Between 1998 and 2002, nearly 15 million wild-caught amphibians were legally

imported into the United States. Considering that there is also a large illegal trade in amphibians (the numbers of which are never reported), that the United

States accounts for only about 15% of the world's amphibian trade, and that many amphibians are also used domestically in their country of harvest, it is

likely that well over 100 million amphibians are removed from the wild each year. This level of harvest is without a doubt unsustainable, and is a large

contributor to population declines in many regions.

Amazing facts about frogs

How many amphibian species are there?

There are 6,317 amphibian species, of which 5,576 are anurans (frogs and toads), 566 are caudates (newts and salamanders), and 175 are gymnophiones

(caecilians).

What's a caecilian?

Caecilians are amphibians that lack limbs. They look a bit like earthworms or snakes and can grow up to 1.5 m (5 ft) in length. As they generally live

underground, they are the most under-studied group of amphibians.

Do all amphibian species have tadpoles?

No. Some caecilians give birth to live young and some salamanders have larvae that essentially resemble the adult stage, but with external gills. There are

many terrestrial frog species that emerge as froglets directly from the egg, bypassing the tadpole stage altogether. This adaptation allows them to live far

from water bodies (on mountain tops for instance), and provides the parents with an increased ability to guard their eggs, which are laid on land. It also

removes a serious risk that aquatic larvae must face: predation by fish or dragonfly larvae. Many terrestrial salamanders employ this strategy as well.

How long have amphibians been around?

Amphibians are the oldest land vertebrates. Ichthyostega was an amphibian species that lived in Greenland 362 million years ago.

Gastric brooders

The Northern & Southern Gastric Brooding frogs Rheobatrachus vitellinus and R. siluslived in eastern Australia. These amazing frogs could actually shut down

their gastric juices while rearing their young inside their stomachs! They therefore held great promise for advances in human medicine, as research on these

frogs may have resulted in a cure for ulcers.Unfortunately, the gastric-brooding frogs vanished within a few years of being discovered by scientists--the health

of humans and frogs is clearly intertwined. On the right you can see a tiny R. silus froglet emerging from its mother's mouth. (Photo by D. Sarille; top photo

of R. vitellinus is by M. Davies)

Smallest frog

The smallest frogs are the Paedophryne dekot and Paedophryne verrucosa from Papua New Guinea, sizing in at only only 9 mm in length. Next up is the

critically endangered Cuban frog Eleutherodactylus iberia.

These frogs measure only 10 mm (0.4 in) when fully grown. They are threatened by pesticides, and by large-scale mining operations thatdestroy their

habitat (Photo of E. iberia by M. Lammertink)

Largest frog

The world's largest frog is the Goliath Frog Conraua goliath, which lives in western Africa. They can grow to be over 30 cm (1 ft) long, and weigh over 3 kg (6.6

lbs). This species is endangered, due to conversion of rainforests into farmland, and due to their being used as a local food source.

What does amphibian mean?

The word amphibian is derived from Greek and means 'two lives', referring to the fact that most amphibians spend their larval stage as aquatic, herbivorous

tadpole, and their adult stage as terrestrial carnivore. However, some amphibians spend virtually their entire lives in the water (i.e. African clawed

frogs Xenopus laevis, and mudpuppies Necturus). Others, like the Puerto Rican coqui Eleutherodactylus coqui or Dunn's salamanderPlethodon dunni from

Oregon, spend their entire lives on land: they lay their eggs in moist leaf-litter, bypass the tadpole stage and may never enter a water body. (Photo is of

Whistling Treefrog Litoria verreauxii)

How do amphibians breathe

Tadpoles have gills like fish, and most adult frogs have lungs like yours. However, amphibians have permeable skin that allows them to absorb both water and

oxygen directly from the environment, right through their skin. Plethodontid salamanders have no lungs: they breathe solely through their skin and through

the tissues lining their mouths. The world's first known lungless frog, Barbourula kalimantanensis, was recently found in the jungles of Borneo. The largest

lungless amphibian is an 80 cm (2.5 ft) caecilianAtretochoana eiselti from Brazil.

Thought only birds built nests?

The Australian stony creek frogs Litoria wilcoxii and Litoria jungguyoccasionally build a sand nest for their eggs. In the photo at right, eggs are in the center of

the nest, which is immediately beside a stream. Thus the eggs are kept in a moist environment, safe from fish for the time being. The next large rain will wash

them into the stream and they will emerge as tadpoles.

Toxins

Most toxic amphibians (like cane toads or poison dart frogs) accumulate their toxins from the insects they eat. But Australia's critically endangered

Corroboree frogsPseudophryne corroboree and P. pengilleyimanufacture their own toxins. They may be the only vertebrates capable of such a feat.

What's up with the 6-legged frogs?

Frog deformities have caused alarm since the early 1990's, when high numbers of frogs in the Midwest were found with missing limbs, extra limbs or other

developmental abnormalities. Many of these deformations are caused by a trematode parasite Ribeiroia ondatrae that burrows into tadpoles' hind limbs.

Why did the malformation rate increase so dramatically in the last two decades? This is unknown, but it may be due to increased levels of eutrophication (an

un-natural state caused by excessive amounts of fertilizer entering a water body), which allowed snails that are used by the trematode as an intermediary

host to increase in numbers, thus providing optimal breeding conditions for the trematode. Furthermore, pesticides have been shown to weaken frogs'

immune systems and make them more vulnerable to trematode infections. The photo on the right is a 6-legged Spotted Grass FrogLimnodynastes

tasmaniensis. Kind of cool, but in a not-so-cool kind of way.

Old tadpoles

Some frogs breed in ephemeral pools that form after heavy rains. To ensure that their tadpoles do not die when their puddle dries, the tadpoles are often

adapted to metamorphose quickly, perhaps within a week or two. Other frogs, however, like the Tailed frogAscaphus truei from the Pacific Northwest or

Australia's Barred Frog Mixophyes live in permanent ponds or streams and can remain in the tadpole stage for 2 or 3 years.

Frozen frogs

Wood frogs Rana sylvatica are the only North American frog that lives above the Arctic Circle. Frogs are ectotherms (cold-blooded) meaning they cannot

internally control their body temperatures. Wood frogs are adapted to cold winters being able to survive a deep freeze: Their breathing, blood flow, and

heartbeat stop, and ice crystals form beneath their skin. While ice crystals in human skin would result in serious problems (frostbite), wood frogs are safe

because high glycogen levels in their cells act like anti-freeze, restricting the frozen areas to the extra-cellular fluid, where no tissue damage will occur. Cool

frogs!

Burrowing frogs

Frogs inhabit some of the driest regions on Earth. As frogs need to remain moist to survive, some frogs burrow underground to avoid the hot dry weather up

above. They have specialized shovel-like pads on their arms or legs that let them to go up to 1.5 m (5 ft) down. If no rains come, that's fine. These frogs slow

down their metabolism and enter a state called aestivation, which is similar to hibernation. And they shed layers of skin that surround them like a protective

cocoon to retain moisture. Some frogs remain underground for 10 months. When the rains come, these frogs appear en masse on the surface for the biggest

party of the year. (Photo: Ornate Burrowing frog Limnodynastes ornatus in New South Wales)

Pre- Production level

Story

Model sheet

Storyboard

Modeling

Blend shapes ( used for Animation)

Unwrapping

Production level

Texturing

Rigging

Skinning

Tracking & Match move

Animation

Post production level

Lighting

Rendering

Editing & Compositing

Sound effects

Story

Our story revolves around a Frog in which all its basic movements like crawl, jump and croak are shown.

The basic story is that a frog tries to catch a fly but fails. It again tries to eat the fly but since it is on busy road, it is shown

that the frog gets crushed under a car. In the very next shot, it is shown that the frog escaped the car and instead of the frog an apple

is crushed.

Model sheet

Storyboard

Species Name

RANA CLAMITANS MELANOTA

Common Name

Green, Brown & Bronze Frog

Diagnostic Features

Size: 8cm

Color: Green to Brown or Bronze

Natural History

Habitat

This frog shelters in logs and crevices, lives in swamps and near streams.

Behaviour

Diurnal and nocturnal.

Breeding

Breeding occurs from March to August, primarily May to June.

About 3000 eggs are laid in a raft like surface film.

Summer breeder in usually permanent, often swampy sites.

Range: Green & Bronze Frog

In North America, Vancouver Island, New Jersey, British Columbia and Washington.

Modeling

Before starting any model collect information about anatomy & related images.

For organic modeling

Select any image, using that image as a reference draw front & side view, scale ratio should be maintained in notepad file.

Import those images into Maya software.

Before starting the actual modeling, first we have to do block modeling.

Block modeling is used to know the perfect proportions of the model, any corrections regarding proportions in the model

Edit in the block model itself.

Process of modeling

The most beautiful & difficult part in any organic modeling is eye.

Place the eyeball, start modeling eye part using any polygon primitive (ex: plane).

Nose & mouth part modeling will be continued after eye part is completed.

Head modeling will be completed after model ear & inner mouth part.

Now, attach the head parts into a single object.

After completing head part, start body modeling

Attach head with body.

Using cylinder primitive, start fore limb & hind limb modeling.

Fore limb hand & Hind limb foot.

Attach hand with palm & leg with foot.

Before attaching body with the limbs, vertices should be same.For merging both objects into a single object.

Model is in perspective view.

Wireframe mode of model in view port (Top, Perspective, front & Side views)

Before exporting model into .obj file format for unwrapping.

Blendshapes

Breathing, Nostrils, Croak, Stomach & Eye blink.

Following check list should be maintained.

Proportions & looping of the model.

Scale ratio should be equal in whole project.

Clean up

Normal’s.

Merging of vertices should be perfect & remove extra faces from the model, if it’s there.

Place the model at origin (0, 0) on the grid.

Delete by type history, freeze transformation & center pivot.

Do not combine the different objects into a single object, group it with proper naming.

Outliner should be cleaned (no transform nodes should be there).

Then export the model into .obj file format for unwrapping purpose.

Unwrapping

Using Head us UV layout software, unwrapping is done.

For texturing the frog model, I used two UV's sets.

Snapshot of the unwrap, which is obtained in the Headus UV layout software.

Eye texturing is separately done in the Maya software using adobe Photoshop.

Texturing

After unwrapping the model in Headus UV layout software, the frog model is exported in .obj file format to transfer the UV's to the original frog model in

Maya software.

Transfer the UV's of the frog model, again exported the final unwrapped model in .obj file format for texturing in Mud box software.

These are the Stamps & Stencils used for sculpting & texturing the model.

Sculpting

Step by step sculpting is done, using different layers in the mudbox.

Final output of sculpting.

Sculpting in four views (Front, Side, Bottom & Top)

Texturing

In Mud box, itself coloring is done.

If u texture the model in 3d software, 0.05% of seam can be seen.

If model is textured using any 2d platform like Photoshop, then seam will be seen clearly. Need to merge the edges of the seam properly in order to avoid the

seam visibility.

Texturing (Color) in four views (Front, Side, Bottom & Top)

After sculpting & texturing the model.

Following maps should be extracted from the Mud box software.

Color map (Color node), Normal map (Bump node), Vector Displacement map (Displacement node) & Ambient Occlusion map (Blend with color map) -

Multiply (Blend mode).

Color map Color map is connected to color node in Maya software.

Legs,Eyes, Inner mouth & Tongue - color map Body, Hand &Foot - color map

Normal map

This map is created based upon the normal direction of the face in the model.

Only illusion is created, it will not change the geometry of a model.k

Normal map is connected to bump node in Maya software (Tangent space normal).

Legs, Eyes, Inner mouth & Tongue - Normal map Body, Hand &Foot - Normal map

Vector Displacement map

Instead of displacement map, vector displacement map is used in displacement node.

Vector displacement map have both RGB + Black & White information.

Legs, Eyes, Inner mouth & Tongue – Vector Displacement map Body, Hand &Foot – Vector Displacement map

Ambient occlusion map

To extract this map, lights are required.

Create lights in the view port in different angles in order to fall light on the model.

Blend ambient occlusion with the color map using blend mode multiply.

Legs, Eyes, Inner mouth & Tongue – Ambient occlusion map Body, Hand &Foot – Ambient occlusion map

References used for modeling & texturing are

Rigging & Skinning

Rigging Process

We Used basic Quadruped rigging to rig the frog

In this Quadruped rigging we used

a) fk/ik switch

b) stretch and squash to tongue and body and

c) Advanced spine twist for good deformation.

After completing the bone structure rig, we gave custom attributes to hands and legs for folding, spread and bending.

Also assigned advanced twist to hand with pole vector and linked them nice Nurbs curves as controls.

For Breathing , Crock and Other Deformations we used BLENDSHAPES with a GUI editor placed on the top of the frog model.

GUI editor placed on the top of the model includes Eye blink, Crock, Breath etc,.

Skinning Process

We used basic bind skin process to get the frog moved according to the rig and system would not get hanged due to over load

After the whole Skinning process completed we also used small correctives to make the deformation of the skin even better

Animation Process

According to the script and storyboard we have total 9 shots to animate.

We have 2 characters a) Frog and

b) Fly.

Animation of frog includes Crawling, jumping and Stretching its tongue to catch a fly.

Animation of fly includes fly cycle with loop and settling on floor.

Planning

First we have done some 2d planning for rough estimation of timing and spacing.

Then we drew flow charts for frame calculation.

After basic 2d work is completed we started animating the frog in 3d software.

In maya 3d software we did all the animation of fly and the frog.

fly animation includes looping of the fly wings and goes with very fast action.

Blend shape animation is very enjoyable and nice to see.

By doing the animation for tracked footage we learned a lot of placing the contacts and maintain the frog animation suitable.

The interaction of fly and frog is very challenging and we sort it out by using the 2d calculations of the frame.

Tracking & Match move

Process of Match move

Import footage in PF track software.

Composition in PF track should be same as that of footage video size ( 1920*1080).

Focal length -50mm(can be noted while shooting the footage).

color correction of the footage should be done.Because, we can adjust the contrast points in the footage.

Then, press Auto track option in PF track.

After tracking you will get track points on the footage.

Estimate the focal length( if u knw focal length-directly you can give it).

Then solve option is used to create grid on the footage.

Select best point in the footage.

Make it as a centre of origin.

Export it to Maya ASCII format.

open Maya scene & build mesh for the footage & finally apply checker map to the footage.

Following shots are Match move as above process.

Shot 1 & shot3

Shot 4 & shot 5

Shot 7 & shot 8

Shading, Lighting & Compositing

Shading Networks

Shading network of Body

I have taken several maps to get depth for the character from the Texturing Department.

Color map, Normal map, Ambient occlusion map & Vector displacement map.

Connections

To get the texture information of the character I connected color map to color node of the blinn shader.

To get the RGB information normal map was connected to bump.

To get the black and white and RGB information vector displacement map was used.

Shading network of Legs

Connections

To get the texture information of the character I connected color map to color node of the blinn shader.

To get the RGB information normal map was connected to bump.

To get the black and white and RGB information vector displacement map was used.

Shading network of Eyes

Connections

To get the color information on eye I used the color map on color node.

Shading network of body with Ambient occlusion

Connections

Due to two UV sets the occlusion shader was taken separately for body & legs.

To get the bumps and dents information of the frog’s body I used the same maps in Ambient Occlusion also.

To get maximum depth i gave sample rate around 256.

Shading network of legs with Ambient occlusion

Connections

Due to two UV sets the occlusion shader was taken separately for legs.

To get the bumps and dents information on frog’s legs I used the same maps in Ambient Occlusion also.

To get maximum depth I gave sample rate around 256.

Lighting

I have taken HDRI images for lighting. I have taken several images in three exposures. But the images didn’t stitch properly.

But using the images I have analysed the lighting in the environment and I composed the clip.

First I have started lighting by taking the source light along with shadows.

And then along with source light I have taken the fill lights.

At last I have added the bounce lights along with fill and source lights

Render passes

This is Ambient Occlusion pass rendered in Mental ray with character’s Primary Visibility On & Diffuse pass rendered in Mental Ray.

This is the merge of Ambient Occlusion along with Diffuse with the blend mode of Multiply.

After the blending I have done color correction according to the environment.

Fusion flow

This is the Merge of Occlusion, diffuse

And Specular with a blend mode of Screen.

Fusion flow

Fusion Flow for the entire composition

Final Composition from one of the Frame.

This is the final composition done for the image.

PRODUCTION PIPELINE

Problems faced during PRE PRODUCTION level

Script

Since this is our first live action and CG mixed project, we decided to do a basic and simple concept.

Our Faculty helped us a lot in deciding a simple and great script.

Shooting (live footage)

Some of the shots were shot manually as the tripod was not flexible.

HDRI images shooting become very inconvenient due to rapid climatic changes.

Modelling

Originally our dissertation character was a salt water Crocodile. Due to some reasons the character got changed to Frog. This was the reason for

the late submission of our model.

PRODUCTION

Texturing

System did not support the Mudbox software. Files got corrupt.

Had to Texture the files again.

Ambient occlusion maps did not render because of low configuration systems.

Rigging

We had rotational values in some of the joints. So, while animating the hands and legs, they got deformed.

Making the contact poses with hands and legs was a bit of concern. Had to rig the hands and legs again

Skinning

It is a general mesh binding procress, not like muscle deformation etc,. So we tried our level best to skin the frog up to our knowledge.

Tracking

The modelling of the rock was a bit difficult.

Match move

Focal length and the grid alignment was very difficult in some shots.

Animation

The stone modelled in the scene was very sharp and not proper. So it was very difficult to put the contact poses.

Due to the deformation of the legs, we were not able to stretch the legs to a maximum extent.

POSTPRODUCTION

Lighting

The HDRI images which were taken during the shoot, did not stitch properly. Instead of the image based lighting (IBL), manual lighting was used.

Rendering

Geometry cache did not export properly. Even if they were imported into the scene, the placement of the character was not coming properly. The

rendered scenes had to be rendered again.

Some of the images in shadow pass were not rendering. So we had to manually render each frame.

Editing and Compositing

The grains were being animated in the fusion software. We had to look for another alternative.

Softwares used

Autodesk Maya (Modeling, Lighting & Rendering)

Headus UV layout pro (Unwrapping)

Autodesk Mud Box (Texturing)

PF Track (Tracking & Match move)

Fusion (Compositing)

Silhouette (Roto)

Adobe After effects (Title animations)

Adobe Photoshop

Microsoft office

Thank you