Crab

Introduction:

Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" οura = tail usually entirely hidden under the yhoraxThey live in all the world's oceans, in fresh water, and on land, are generally covered with a thick exoskeleton and have a single pair of claws. Many other animals with similar names such as hermit crabs king crabs, porcelin crab,horse shoe cdrabs and crab lice are not true crabs.

Evolution:

Crabs are generally covered with a thickexoskeleton  composed primarily of calcium carbonate and armed with a single pair ofchelae (claws). Crabs are found in all of the world's oceans, while many crabs live in fresh water and on land, particularly in tropical regions. Crabs vary in size from the pea crab a few millimetres wide, to the japanes apider crab with a leg span of up to 4 metres (13 ft).

The underside of a male (top) and a female (bottom) individual of pachygrapsus marmoratus, showing the difference in shape of the abdomen.


Use in food:

Crabs are prepared and eaten as a dish in several different ways all over the world. Some species are eaten whole, including the shell, such as soft shell crab with other species just the claws and/or legs are eaten. The latter is particularly common for larger crabs, such as the snow crab. Mostly in east asian cultures, the roe of the female crab is also eaten, which usually appears orange or yellow in colour in fertile crabs.

The biggest importers, and therefore countries where eating crab is immensely popular, are Japan, France, Spain, Hong Kong, the US, Canada and Portugal.