1. Word Games
  2. Word of the Day
  3. New Words & Slang
  4. Video
 

mollusk


mollusk

/

Representative mollusks. Bivalves have a shell with two halves. Filter feeders, they take in food …—© Merriam-Webster Inc.

Any of some 75,000 species of soft-bodied invertebrate animals (phylum Mollusca), many of which are wholly or partly enclosed in a calcium carbonate shell secreted by the mantle, a soft covering formed from the body wall. Between the mantle and the body is the mantle cavity. Mollusks occur in most habitats from the deep sea to high mountains. Living mollusks are usually grouped into eight classes: Gastropoda (see gastropod), Bivalvia or Pelecypoda (see bivalve), Cephalopoda (see cephalopod), Scaphopoda (tusk shells), Aplacophora (Solenogasters), Caudofoveata (sometimes included in the Aplacophora order), Polyplacophora (chitons), and Monoplacophora. Mollusks are economically important as food, and their shells are widely used in jewelry and decorative items.

Variants of MOLLUSK

mollusk or mollusc

This entry comes from Encyclopædia Britannica Concise.
For the full entry on mollusk, visit Britannica.com.

Learn More About MOLLUSK

Seen & Heard

What made you look up mollusk? Please tell us what you were reading, watching or discussing that led you here.

Test Your Vocabulary

Take Our 10-Question Quiz

Name That Thing

Take our visual vocab quiz

Test Your Knowledge »

True or False?

A quick quiz about stuff worth knowing

Take It Now »

Join Us on FB & Twitter

Get the Word of the Day and More

Facebook | Twitter

Get Our Free Apps

Voice Search, Favorites,
Word of the Day, and More

iPhone | iPad | Android | More