| DESCRIPTION |
Shrimps belong to the order Decapoda, a crustacean order which also includes the lobsters, true crabs, and hermit crabs. All decapods possess a full carapace or “head shield”, and, eponomously, five pairs of walking legs. Their first three pairs of thoracic appendages are modified into “maxillipeds”, or feeding legs.
Shrimps are distinguished from the other decapods by having the front-most section of the abdomen about the same size as the rest of the sections, and by having five pairs of abdominal appendages, or pleopods, adapted for swimming.
There are more than 3,000 living species of shrimp worldwide. Many are tiny, or inhabit niches unsuited to mass harvest. Those harvested on a commercial basis share two characteristics: they are relatively large, ranging roughly from 2-10 cm. carapace length, and they school, shoal, migrate toward baited traps, or otherwise aggregate so that they are amenable to capture. Worldwide, about 40 species of shrimp meet these criteria and are harvested commercially. About ten species have been raised in captivity; for some species, such as the Pacific white shrimp Penaeus vannamei, selective breeding is developing truly “domesticated” breeds of shrimp.
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