Intro to Chordates p

Superclass Agnatha Integument: slimy skin Temperature control: ectotherm Limb Structure: no paired limbs Gas Exchange: gills Fertilization: external

Class Chondrichthyes Integument: scales Temperature control: ectotherm Limb Structure: 2 pairs of fins Gas Exchange: gills Fertilization: internal

Class Osteichthyes Integument: slimy skin and scales Temperature control: ectotherm Limb Structure: 2 pairs of fins Gas Exchange: gills Fertilization: external

Class Amphibia Integument: thin, moist skin Temperature control: ectotherm Limb Structure: 2 pairs of legs Gas Exchange: gills, lungs, skin Fertilization: external

Class Reptilia Integument: dry, scaly Temperature control: ectotherm Limb Structure: 2 pairs of legs Gas Exchange: lungs Fertilization: internal

Class Aves Integument: feathers Temperature control: endotherm Limb Structure: wings, one pair legs Gas Exchange: lungs Fertilization: internal

Class Mammalia Integument: hair Temperature control: endotherm Limb Structure: 2 pairs of legs Gas Exchange: lungs Fertilization: internal

Hallmarks of Phylum Chordata Notochord Single, tubular, dorsal nerve cord Pharyngeal slits Postanal tail Endostyle * Characteristic present at some point during development!!!

Superclass Agnatha p “circular mouths” In place of jaws is an oral sucker Most primitive of all fish External fertilization No stomach Heart: 2 chambers (1 ventricle; 1 artia) No fins Eel body form Poor eye development (hagfish only) Pore-like gill openings

Class Myxini Includes hagfish Feed on dead or dying fish Scavengers Completely blind, well developed sense of smell and touch Generate large amounts of slime for defense

Class Petromyzones Includes lampreys Most are parasitic, feed on blood and fluids of fish Destructive to fisheries (ex. Great Lakes) Millions of dollars lost each year