Vertebrae Notes

notochord

Stiff rod of cartilage cells that protect the dorsal nerve chord.

pharyngeal pouches

Pouches in the throat, that develops into gills for most.

subphylum cephalochordata

has no vertebrate; lanclet

subphylum urochordata

has no vertebrate; during larval development they are free swimming

subphylum vertebrate

lose their notochord early in embryonic development.

class agnatha

“Jawless” Fish

hagfish

Has a simple simple skull but does not develop a true vertebral column

lamprey

No true fins or lateral appendages

traits of jawless fish

sucker type mouth; 7 pairs gills

what type of mouth does jawless fish have

cyclostome

class chondrichthyes

sharks, rays, and skates

traits of a shark

each gill is housed in a separate chamber,

how many gills do sharks have

4-7 pairs of gills

placoid scales

protrude through the skin

subterminal mouth

mouth is pushed back and tucked under