In details

Clam Classes



Octopus: Cephalopod Mollusk

Introduction

Mollusks, soft-body invertebrate animals, can be classified according to their main physical characteristics (physiology). There are ten classes of mollusks, but we will see only the main ones.

Main classes of Molluscs and their characteristics:

Cephalopoda

- They are marine mollusks.

- Body with bilateral symmetry.

- Well developed head.

- Modified feet in tentacles (begin in the cephalic region).

Examples of cephalopods: squid, folk, argonaut and nautilus.

Polyplacophora

- They have shells composed of 8 dorsal plates.

- The habitat of these mollusks is the rocky shore present on the coast.

Examples: Chitons

Gastropoda

- There are species of terrestrial, marine and freshwater gastropods.

- Shell composed of a valve. Some species have no shell.

Examples: slugs and snails.

Bivalvia

- May be found in fresh or salt water (oceans).

- Have outer shell composed of two valves.

- Flattened body on the side.

Examples of bivalves: leg leg (mussel), shells, oysters

Monoplacophora

- They are still little known by marine biologists.

- They live in deep ocean waters.

- They have bilateral symmetry in the rounded shell.

- The movement is done through a circular foot.

Examples: neopoylin (Neopilina galatheae)