Intro to Chordates

p. 270-274

Superclass AgnathaIntegument: slimy skin

Temperature control: ectotherm

Limb Structure: no paired limbs

Gas Exchange: gills

Fertilization: external

Class ChondrichthyesIntegument: scales

Temperature control: ectotherm

Limb Structure: 2 pairs of fins

Gas Exchange: gills

Fertilization: internal

Class OsteichthyesIntegument: slimy skin and scales

Temperature control: ectotherm

Limb Structure: 2 pairs of fins

Gas Exchange: gills

Fertilization: external

Class AmphibiaIntegument: thin, moist skin

Temperature control: ectotherm

Limb Structure: 2 pairs of legs

Gas Exchange: gills, lungs, skin

Fertilization: external

Class ReptiliaIntegument: dry, scaly

Temperature control: ectotherm

Limb Structure: 2 pairs of legs

Gas Exchange: lungs

Fertilization: internal

Class AvesIntegument: feathers

Temperature control: endotherm

Limb Structure: wings, one pair legs

Gas Exchange: lungs

Fertilization: internal

Class MammaliaIntegument: 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 Agnathap. 287-291

“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 MyxiniIncludes hagfish

Feed on dead or dying fishScavengersCompletely blind, well developed sense of smell

and touchGenerate large amounts of slime for defense

Class PetromyzonesIncludes lampreys

Most are parasitic, feed on blood and fluids of fishDestructive to fisheries (ex. Great Lakes)

Millions of dollars lost each year