Phylum Chordata --Vertebrate chordates: fishes, amphibians, reptiles, birds, mammals --Invertebrate chordates: tunicates and lancelets
Jan 02, 2016
Phylum Chordata--Vertebrate chordates: fishes, amphibians, reptiles, birds, mammals--Invertebrate chordates: tunicates and lancelets
Characteristics (embryonic development)
Dorsal hollow nerve cordNotochord—firm flexible supporting rod located just below the nerve cordGill slits—paired opening along the pharynxPost anal tail…extends beyond the anus
EndothermicWarm blooded..temp is controlled by internal processes
EctothermicCold blooded..temp is regulated by external environment
Three Subphylums
1. Urochordata--tunicates (sea
squirts)--most adults are
sessile, squirt water when disturbed
2. Cephalochordata
LanceletsCan swim but prefer to stay buried in the sandFilter feeders
3. Vertebrata (humans)
Animals with backbonesDorsal hollow nerve cord becomes the spinal cord and brainNotochord is the backboneGill slits become other breathing organsTails are kept in most vertebrate animals
Six Classes
1. Agnatha--no jaw (jawless fish)--skeleton made of cartilage--snake-like body without
paired fins (not good swimmers)
Examples
Lampreys—attach to other fish using their round mouth and its rasping parts (parasites)Hagfish—scavengers, move slowing through cold water using tentacles to locate dead and dying fish
Hagfish
Have you ever gone fishing? Tell me about your experience.
ORPick your favorite fish and describe it. Why do you like it.
2. Chondrichthyes
Sharks, skates, raysGeneral characteristics
Skeleton mostly made of cartilageHave scales made of dentinExcellent sense of smellLateral line picks up vibrations
Sharks—torpedo shape bodyfertilization is internal and the eggs develop internallyYoung sharks are called pupsMust keep moving to keep water flowing through gillsOily liver helps buoyancy
Skates and Rays—basically benthic (bottom) lie and wait animalsHave a tail which can cause painPectoral fins are expanded and they look like they are gliding in the water
3. OsteichthyesCharacteristics
Bony skeleton—bony fishesSwim bladderScalesPaired finsOperculum flap covering gills2 chambered heartkidneys
Page 608…Read the life cycle section
Using complete sentences, explain the life cycle of a frog
Compare and contrast the animals in the class chondrichthyes to the animals in the class osteichthyes.
4. Amphibians
frogs, salamanders, toads, caeciliansSpend part of their life in the water and part living on land
Tadpole Frog
Frogs
Have a nictitating membrane over their eye…keeps eye moist in air and protects in the waterHear through a tympanic membrane (detect sound through air and water
Digestive System
Path of food Mouth, esophagus, stomach, small intestine, large intestine, cloaca
Undigested food along with products from the excretory system and reproductive system empty into the cloaca
Respiratory
Breathe using lungsDiffuse oxygen through skin (must stay moist)Tadpoles have gills for gas exchange
Circulation
Double loop circulationThree chambered heartDeoxygenated blood flows to the heart, then it is pumped to the lungs where it is oxygenated, then it flows back the heart to be pumped to the rest of the body
Metamorphosis
Frogs are the only amphibian to go through this process
EggTadpole…tail, gills, lives in waterFrog…no tail,lungs,has legs, lives on land
Page 608
A froggie eats bugs. Tell me the pathway that the bugs will travel as they go from the froggie’s mouth to its anus.
Look at the five pictures on page 804
List some adaptations that you see for these reptiles.Must have at least 5
5. Reptiles
EctothermicEgg-laying..soft, leathery shellsScaly dry skin..adaptable to life on landInternal fertilization
Breathe with lungsEndoskeleton3-chambered heart except crocodilians
Kidneys remove wastes and absorb most of the waterShed skin
Eggs are called Amniotic eggs b/c they have a fluid filled amnion sac which surrounds the embryo
6. Aves
FeathersContour feathers—have a stiff central barbDown feathers—short shafts, for insulationOil gland at base of feather..waterproof
Wing flowBones are hollow to reduce density
Fused collarbone and vertebra…furcula
4-chambered heart
Endothermic (warm blooded)High metabolism (eat a lot!)
Digestive system..crop (storage), gizzard (grinding…often contains stones)
Unique respiratory system
Anterior and posterior air sacs in addition to lungsAir flows in air sacs in only one direction (pg 810)
Excretion..no urinary bladder
Special glands around the eyes remove excess salts
7. Mammals
Mammary glands..produce milk to nurse youngFur or hairEndothermicWell developed brainsInternal fertilization…live birth
Breathe with lungsContain air sacsDiaphragm..muscle under lungs which helps breathing
Examples…•Monotremes: mammal that lays eggs (duck-billed platypus
•Marsupials: Kangaroo..give birth to small immature young that further develop inside mom’s pouch (Pg 829)
•Placental: young develops more fully before birthPlacenta..organ attached to mom and fetus
Mammalian Teeth
Page 823
Orders of Placental MammalsPage 830