<tr><td>Kingdom:<td>Animalia
<tr><td>Phylum:<td>Arthropoda
<tr><td>Subphylum:<td>Crustacea
<tr><td>Class:<td>Malacostraca
<tr><td>Order:<td>Decapoda
<tr><td>Suborder:<td>Pleocyemata
</table>
</table>
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.
Groups of crabs include:
A number of animals with a similar shape are commonly called crabs, including the crab louse (an insect), the Horseshoe crab (in the class Merostomata). The crab louse is the origin of the slang term "crabs" for an infestation of pubic lice.
A crab is any of various machines used to hoist heavy objects.
