Translations:AY Honors/Marine Invertebrates/Answer Key/73/en

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  Crassostrea gigas
  (Pacific Oyster)
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  Saccostrea glomerata
  (Sydney Rock Oyster)
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  Pinctada margaritifera
  (Pearl Oyster)

The common name oyster is used for a number of different groups of bivalve mollusks, most of which live in marine habitats or brackish water. The shell consists of two usually highly calcified valves which surround a soft body. Gills filter plankton from the water, and strong adductor muscles are used to hold the shell closed.Some of the groups known as oysters, also known as mullusks (true oysters), are highly prized as food, both raw and cooked (though the Bible categorizes them as unclean, and therefore unfit as human food). Some other groups also called oysters, such as pearl oysters, are not widely eaten, at least not since recent times. True (edible) oysters are incapable of making gem-quality pearls, although the opposite idea is a commonly-encountered misapprehension, often seen in illustrations or photographs where an edible oyster shell is mistakenly paired with a gem-quality pearl.