Chinese mitten crab

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iChinese mitten crab

Scientific classification

Kingdom:	Animalia
Phylum:	Arthropoda
Subphylum:	Crustacea
Class:	Malacostraca
Order:	Decapoda
Suborder:	Pleocyemata
Infraorder:	Brachyura
Superfamily:	Grapsoidea
Family:	Grapsidae
Genus:	Eriocheir
Species:	E. sinensis

Binomial name

Eriocheir sinensis
H. Milne Edwards, 1853

The Chinese mitten crab (Eriocheir sinensis), also known as big binding crab (大閘蟹) and Shanghai hairy crab (上海毛蟹), is a medium-sized burrowing crab found in the coastal estuaries of eastern Asia from Korea in the north to the Fujian province of China in the south.

Mitten crabs spend most of their life in fresh water, but they must return to the sea to breed. During their fourth or fifth year in late summer, the crustaceans migrate downstream, and attain sexual maturity in the tidal estuaries. After mating, the females continue seaward, overwintering in the deeper waters. They return to brackish water in the spring to hatch their eggs. After development as larvae, the juvenile crabs gradually move upstream into fresh water, thus completing the life cycle.

This species' distinguishing features are the dense patches of dark hair on its claws. The crab's body is the size of a human palm. The carapace width is 30 to 100 mm and the legs are about twice as long as the carapace is wide.

This species is very invasive and has spread to North America and Europe, raising concerns that it competes with local species, and its burrowing nature damages embankments and clogged drainage systems. It was reported in the London Evening Standard in 1995 that the residents of Greenwich, UK, reported seeing the Chinese mitten crabs coming out of The River Thames and moving towards the high street.

Hairy crab as famous Shanghai cuisine.

In contrast, the crab is a famous delicacy in Shanghai cuisine and is prized for the supposed aphrodisiac qualities of the female crab's ovaries. Concerns have been raised that the population and origin of the crab may be affected because of over fishing of the species in the Yangtze River. Today Yangcheng Lake is the most famous area for the Chinese mitten crabs. The crab meat is believed by the Chinese to have a "cooling" (yin) effect on the body. Chinese spend hundreds of yuan just to taste a small crab from that lake. Most of these are exported to Shanghai and Hong Kong, and high-profit foreign markets. Responding to the spread of the crab to the West, businessmen have started seeing it as the new source of crab for supporting the huge appetite in China market.

Due to crossbreeding with more robust Japanese varieties, there are concerns that native crabs will be outnumbered or even wiped out by competition from crossbred crabs. One proposed scheme involves importing unwanted crabs from Europe, where they are seen as a pest, to replenish local pure-bred stock.

The price of the crab varies from RMB10 to RMB300, depending on its origin, gender, weight and seasons. A crab with 300 grams is sold around RMB250 to RMB300 in the market last season.