Mollusk Study Guide

Structure that removes ammonia

Nephridia

Phylum of mollusks

mollusca

Instead of brains, less active mollusks have

ganglia

Type of ___mate that mollusks are

coelomates

Free swimming larva stage in aquatic mollusks

trochophore

What do trochophores use for propulsion

cilia

What do clams use to burrow?

foot

What type of digestive tract do mollusks have?

1 way, mouth and anus

How do mussels and clams differ in lifestyle?

Mussels attach to rocks, clams burrow into sand

What is a hermaphrodite?

an animal with both male and female reproductive parts

How do scallops move

by flapping their shells

What do aquatic mollusks use for respiration

gills

Head/foot

primary nervous system

Mantle

layer of tissue over body, forms shell

Visceral mass

contains organs

Shell

used for protection

Four parts of a mollusk

Head/foot, mantle, shell, visceral mass

Two ways a mollusks head/foot can be modified

spade-like for digging, flat for crawling

Class gastropoda

snails, slugs, abalone, nudibranchs

How do gastropods feed

Flexible radula

Class bivalvia

Clams, oysters, mussels, scallops

Class cephalopoda

Octopi, squid, cuttlefish, nautiluses

What do cephalopods use for defense

ink, camouflage, size

Why do gastropod shells coil

Torsion

Gastropod defense methods

nocturnal, ink, recycling nematocysts

Function of the operculum

barrier that seals gastropods in their shells when retracted

What do squid have in place of a shell

Pen

Internal “shell” of cuttlefish

cuttlebone

How do nautiluses control buoyancy?

Regulate gas in their shell

What kind of sight organs do bivalves have?

light-sensing eyespots

How does the head/foot of cephalopods differ from that of other mollusks

Head attached to foot that is divided into tentacles

What do cephalopods’ jaws form

beak