CK12 Life Science

Table 12.1: (continued)

Molluscan Class Number of Species Habitat Features of

Class/Examples

Bivalvia 8,000 Marine (some clams

live in deep ocean

around hot hy-

drothermal vents)

and freshwater.

Most bivalves

are filter feed-

ers (mechanism

whereby suspended

matterandfoodpar-

ticles are strained

from the water,

typically by passing

the water over a

specialized filtering

structure); bivalves

include clams, oys-

ters, scallops, and

mussels.

Scaphopoda 350 Marine Tusk shells

Figure 12.6: A chiton and sea anemones at a tide pool. ( 31 )

As you can see, the majority of mollusk species live in marine environments, and many
of them are found intertidally in the shallow subtidal zone and on the continental shelf.
Freshwater species are represented in the bivalves and gastropods, and some gastropods, like
land snails, and slugs, live on land.