Mollusks

 

The Mollusks are one of the most successful phyla with over 100,000 living species and are found worldwide. Search Ocean Biogeographic Information System (OBIS) for databases of mollusk distribution. They have a head-foot complex, a mantle that secretes a calcium carbonate shell and a gill, suspended in the mantle cavity, which is used for respiration and commonly for suspension feeding. There are several kinds of mollusks:
 
  • Gastropoda (snails),
  • Bivalvia (clams, oysters and mussels),
  • Cephalopoda (squid and octopus),
  • Polyplacophora (chitons) and
  • Scaphopoda (tusk shells).
Mollusks have an important role to play in the ecosystem, varying from the herbivorous chitons feeding on microalgae and seaweeds attached to rocks; bivalves filtering phytoplankton and organic matter in sediment; the shipworm Teredo which bores into wood; to the specialist carnivores like octopuses feeding on individual crab species. Many species are important for aquaculture.
Based on Levinton, J S, �Marine Biology. Function, Biodiversity, Ecology� Oxford University Press.

This is a stamp showing Argonauta argo, the Greater Argonaut. The stamp was issued in 1956 (Michel-Nr. 796) by the former Yugoslavian authorities. (Caption courtesy of James B. Wood)

For more information

Census of Marine Life, now concluded, had a number of projects that included mollusks:
 

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