Temporal range: Ediacaran or Cambrian - Recent
|Caribbean Reef Squid, Sepioteuthis sepioidea|
Molluscs, or mollusks, are an important phylum of invertebrate animals. Most of them are marine. They have huge numbers in-shore, that is, in shallow waters near the shore. They are the largest marine phylum, with about 93,000 recognised species, 23% of all named marine organisms. They also occur in freshwater and on land.
Molluscs are extremely varied: they have great diversity. That may be why there is no word in English for the phylum as a whole. "In an evolutionary sense, molluscs are plastic material".
Most molluscs have shells, but some groups do not: octopods, slugs, and the gastropods known as sea slugs. There is great variety in the phylum, much more so than their ancient rivals, the brachiopods.
Classes of molluscs:
- Cephalopods: Squid, Octopus
- Gastropods: whelks, limpets, snails, slugs, Nudibranchs
- Bivalves: Most shellfish; clams, oysters, scallops, mussels
- Scaphopoda: the tusk shells
- Polyplacophora: Chitons
- Aplacophora: worm-like molluscs
- Many molluscs are eaten as food: clams, oysters, scallops, mussels, squid (calamari) and land snails (escargot)
- Oysters sometimes make pearls, which are valuable and used to make necklaces. Other shells are collected for their beauty and sometimes used to make jewellery.
References[change | edit source]
|Wikispecies has information on: Mollusca.|
- Morton J.E. 1958. Molluscs. London: Hutchinson University Library, p11.
- Barnes, Robert D. 1982. Invertebrate zoology. Philadelphia PA: Holt-Saunders. ISBN 0-03-056747-5.