Chinese Mitten Crab

The Chinese mitten crab, Eriocheir sinensis, also called the Shanghai hairy crab, is a medium sized burrowing crab in the family Varunidae, described by H. Milne-Edwards in 1853 and named for the dense patches of dark bristles on its claws that resemble fur mittens. Its body is roughly the size of a human palm, with a carapace three to ten centimetres wide and legs about twice that length. It is native to East Asian rivers and coastal waters from Korea in the north to Fujian in the south, and can migrate far inland, with records of specimens travelling up to one thousand four hundred kilometres upstream in the Yangtze River. Introduced to Europe and North America, it is considered a serious invasive species, appearing on the European Union's list of invasive alien species of concern, and has been documented in the Chesapeake Bay, the Hudson River and San Francisco Bay. In Shanghai the crab is prized as an autumnal culinary delicacy, especially specimens from Yangcheng Lake, though counterfeit sales are common; in 2012 more than one hundred thousand tons of fraudulent Yangcheng crab were sold when only about three thousand tons were actually harvested there.