Taxonomy• Phylum Chordata
– Subphylum Cephalochordata- amphioxus or lancelet– Subphylum Urochordata- tunicates or sea squirts– Subphylum Vertebrata
• Class Agnatha- jawless and cartilaginous, hagfish and lamprey• Class Chondrichthyes- cartilaginous, sharks and rays• Class Osteichthyes- bony fish• Class Amphibia- cecilians, salamanders, frogs, toads• Class Reptilia- snakes, lizards, turtles, tortoises, alligators, crocodiles,
tuataras• Class Aves- birds• Class Mammalia- dogs, cats, lions, horses, cows, bears, giraffes,
elephants, monkeys, kangaroos, humans, platypus, mice, beavers, seals, sea lions, walruses, whales, dolphins, porpoises, manatees, dugongs, anteaters, armadillos, sloths, bats, shrews, moles, hedgehogs…
Fish
Cold Blooded (Ectotherm)
Warm Blooded (Endotherm)
Class Agnatha
Class Agnatha• No scales• Eel-like shape• Unpaired fins• Cartilaginous skeleton• Jawless• Sucking mouth
Paddlefish Parasitehttp://www.youtube.com/watch?v=AzZao6SVMyc
Lamprey• Up to 24in. (60cm)• Anterior and posterior dorsal fin• Tail fin or caudal fin• Two eyes• Gill slits• Circular, funnel shaped mouth lined with rings of teeth• Attaches by suction, bores a hole, sucks blood and body fluids
Lamprey Life Cycle• Female digs a shallow depression in stream
bed and deposits eggs (25,000 to 100,000)• Males fertilize the eggs- external fertilization• In about 2 weeks the eggs hatch• Tiny wormlike larva burrow into muddy
bottom• Feeds on organic debris and develop for 3-7
years
Ecological Impacthttp://www.youtube.com/watch?v=9JQ6oHjpeqU
Hagfish• Bottom dweller• Mainly eats dead animals• Small teeth for tearing and muscular sucking mouth• Eye spots• Slime glands secrete slime as a defense mechanism
Hagfish Defensehttp://www.youtube.com/watch?v=bqk0mnMgwUQ
Class Chondrichthyes• Cartilaginous skeleton• Cartilage surrounded by tough protein to increase
the strength of the skeleton• Jaws• Paired fins
Sharks• Same basic fins as the fish in Osteichthyes, however,
the dorsal part of the caudal fin is always larger than the ventral part
• Skin appears smooth but actually rough
Shark Mouth• Mouth has razor-sharp triangular teeth that point
inward• Teeth not anchored into bone, but into the skin• If one is lost, another moves forward to replace it
(20,000 in lifetime)• Carnivorous
Digestion• Like Osteichthyes, the stomach is for storage and
digestion occurs in the intestine• All are carnivorous
Respiration• Most sharks have 5 gill slits per side. Few species
have 6 or 7
• Sharks lack a swim bladder• A large liver filled with oils less dense than
water helps them float• Lift provided by the forward motion
Reproduction• Internal fertilization• Claspers- specially
shaped portion of the male’s pelvic fin that helps transfer sperm to females for fertilization
• Most oviparous, some viviparous (very rare outside class mammalia), and ovoviviparous
Rays and Skates• Flat and thin rather than torpedo-shaped like the sharks• Pectoral fins form flat “wings”• Swimming motion is like a bird• Ventral mouth used to eat mollusks, small crustaceans, and to suck
up invertebrates• Stingray- type of ray with sharp, venom filled spine along its tail• Most rays and skates are less than 3.3ft. (1 m)• Manta ray “devilfish” sometimes more than 20ft. (6m)
River Monsters - Alien Fishhttp://www.youtube.com/watch?v=FMIN0XVKfPE
Giant Mantahttp://www.youtube.com/watch?v=yfgJx-ShRGI
Pelican and rayshttp://www.youtube.com/watch?v=cqNxco4xcpI