螃蟹资料英文

Crabs are decapod crustaceans of the infraorder Brachyura, which typically have a very short projecting "tail" or where the reduced abdomen is entirely hidden under the thorax. They are generally covered with a thick exoskeleton, and armed with a single pair of chelae (claws). 6,793 species are known.Crabs are found in all of the world's oceans. Additionally, there are also many freshwater and terrestrial crabs, particularly in tropical regions. Crabs vary in size from the pea crab, only a few millimetres wide, to the Japanese spider crab, with a leg span of up to 4 m.

Crabs are mostly active animals with complex behaviour patterns. They can communicate by drumming or waving their pincers. Crabs tend to be aggressive towards one another and males often fight to gain access to females. [11] On rocky seashores, where nearly all caves and crevices are occupied, crabs may also fight for the best hiding holes.[12]
Crabs are omnivores, feeding primarily on al