It includes such familiar organisms as snails, octopuses, squid, clams, scallops, oysters, and chitons. Mollusca also includes some lesser known groups like the monoplacophorans, a group once thought to be extinct for millions of years until one was found in 1952 in the deep ocean off the coast of Costa Rica.

What allows mollusks to inhabit the extreme environment around deep-sea volcanic vents? Within the bivalves around these vents are symbiotic bacteria that extract chemical energy from compounds in the water. From that energy, the bacteria produce food molecules that the mollusks can use.

The body plan of most mollusks has four parts: foot, mantle, shell, and visceral mass. Mollusks can be herbivores, carnivores, filter feeders, detritivores, or parasites. Snails and slugs feed using a flexible, tongue- shaped structure known as a radula.

Animal Mollusca / Kingdom

Along with the insects and vertebrates, mollusks are one of the most diverse groups in the animal kingdom, with nearly 100,000 (possibly as many as 150,000) described species. This is a list of notable mollusks, ordered alphabetically by class. Also included are extinct mollusks.

Mollusca is the second-largest phylum of invertebrate animals, after Arthropoda; members are known as molluscs or mollusks (/ˈmɒləsks/). Around 76,000 extant species of molluscs are recognized. The number of fossil species is estimated between 60,000 and 100,000 additional species.

their eggs and sperm into the water at the same time, and fertilization is external. A few bivalves and many gastropods that live on land are hermaphrodites, in which fertilization takes place internally. All members of the phylum Mollusca share similar developmental patterns, even though their adult forms vary widely.