Chordate ClassesChordate Classes AgnathaAgnatha – jawless fish – jawless fish (lampreys and hagfish)(lampreys and hagfish) Eel-like, no scalesEel-like, no scales Sucker-like mouthSucker-like mouth Some parasiticSome parasitic Cartilaginous skeletonCartilaginous skeleton

ChondricthyesChondricthyes – – cartilaginous fish cartilaginous fish True jawTrue jaw Gill slits are not Gill slits are not coveredcovered

Spiky scalesSpiky scales Sharks

Rays

Chordate Class: Chordate Class: OsteichthyesOsteichthyes

““Bony Fish” – skeleton Bony Fish” – skeleton made of true bonemade of true bone

Swim bladderSwim bladder Gill cover (operculum)Gill cover (operculum)

Seahorse

Examples: Perch, bass, eels tuna, salmon

Paired fins

Vertebrate Class: Vertebrate Class: AmphibiaAmphibia Begin life in water using gills, and adults Begin life in water using gills, and adults

have lungshave lungs Moist skin – gas exchangeMoist skin – gas exchange External fertilization needs waterExternal fertilization needs water Frogs, salamandersFrogs, salamanders

Adult Frog

Adult Frog

Young Frog

Young Frog Fertilized

EggsFertilized Eggs

TadpolesTadpoles

Vertebrate Class: Vertebrate Class: ReptilaReptila Mostly Mostly

terrestrialterrestrial

Snakes

Lizards

Dry scaly Dry scaly skinskin

11stst amniotic amniotic eggegg

Alligators

Turtles

Vertebrate Class: Vertebrate Class: AvesAves Feathered bodies with Feathered bodies with

scales on their feetscales on their feet EndothermicEndothermic Gas exchange using Gas exchange using lungslungs

Wings (MOST fly)Wings (MOST fly)

Vertebrate Class: Vertebrate Class: MammaliaMammalia

Hair covering the Hair covering the bodybody

Fat under the skinFat under the skin Mammary glandsMammary glands EndothermicEndothermic