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Crab is one of the oldest species on earth. The horseshoe crab dates back over 200 million years and is literally a living fossil. It's easy to tell the difference between a male and female (she-crab) by looking at the underside of the shell (see photos). The female has a broad, triangular-shaped area in the center of the shell, whereas the male has a distinctive, elongated spire in the center.
Crabs are various species of decapods. They are crustaceans with five pairs of legs, the first pair modified to form a pair of pincers, a flattish shell, and a short, broad abdomen folded under its thorax. There are two main groups of crabs: the Brachyura or true crabs, and the Paguroidea, or hermit crabs. Crabs are related to lobsters and shrimps.
Crab
Crab
Crab
Crab
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