1. Education
You can opt-out at any time. Please refer to our privacy policy for contact information.



Blue-line Chiton Blue-line Chiton
Jeff Rotman/Photolibrary/Getty Images

A mollusk is an animal classified in the Phylum Mollusca.

This extremely diverse animal phylum is thought to contain well over 100,000 species, which include animals in the taxonomic classes Polyplacophora (chitons), Gastropoda (animals with one shell, including snails, limpets, and sea slugs/nudibranchs), Bivalvia (animals with two shells - clams, mussels and oysters) and Cephalopoda (octopuses and squids).

  1. About.com
  2. Education
  3. Marine Life
  4. Marine Life 101
  5. Glossary - Marine Life and Marine Biology Terms
  6. What Is a Mollusk?

©2014 About.com. All rights reserved.