detection of prey

used for navigation...in sharks

the two tail lobes are different sizes to provide lift

the two tail lobes are the same size made for speed

sharks

high brain size

they have a weird head

naked skin

no spiracle

flattened grinding teeth

claspers

Osteichthyes have a true ossified internal skeleton where the Chondrichthyes have cartilage

They have a swim bladder or lung that help them with boyancy while the C's do not they depend on their liver mostly for boyancy

O's have an operculum that cover their gill slits where the C's do not

The O's have bony scales including; ganoid, cycloid,ctenoid and cosmoid...C's have placoid scales.

1) Intermolt condition

2) old procuticle seperates from the epidermis, which secretes epicuticle

3) new exocuticle is secreted molting fluid dissolves old endocuticle and solution products are reabsorbed

4) the old epicuticle and exocuticle are discarded

5) new cuticle is stretched unfolded and endocuticle is secreted.

male- v shaped

female-u shaped

grouped by the presence of lophophores

include bryzoans(moss) phoronids and brachiopods(lamp shells)

Radial symmetry

germlayers-epidermis endodermis(gastrodermis)

form true tissue

bilateral symmetry

have a head and a butt

gasropods,nudibrachs,bivalves,cephalopods,

monoplacophora,scaphopods, and polyplacophora 

gills

ragella

muscular foot

prosobranchia

opisthobranchia

pulmonata

Crustacea

pycnogonida

bryzoans

phoronids

brachiopods

pentamerous

have a water vascular system

have an endoskeleton