Crustacea

Class Crustacea

[ Crustacea ]

Photo by : Nikita

Any of various predominantly aquatic arthropods of the class Crustacea, including lobsters, crabs, shrimps, and barnacles, characteristically having a segmented body, a chitinous exoskeleton, and paired, jointed limbs.

[American Heritage Dictionary]

A crustacean is an arthropod with 5 pairs of appendages on 6 segments: 2 pairs of antennae, a pair of jaws, or mandibles, 1 on each side of the mouth, and 2 pairs of manipulatory mouthparts. The number of segments in the body varies, depending on the group. In some forms the body may simply be a trunk. In more advanced types it may be devided into a thorax and abdomen. The thorax has maximum of 8 segments, and the abdomen, 6. ... Reproduction is almost entirely sexual, fertilization is usually internal, and the eggs are attached to the body of the female.

[ National Audubon Society Field Guide of North American Seashore Creatures. ]