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