The Chinese mitten crab, aka Shanghai hairy crab, is a mid-sized burrowing species of crab that is named for their furry claws that look like mittens. They originally hail from rivers, estuaries, and other coastal habitats of east Asia; from Korea in the north to Fujian in the south. They have also, unfortunately, been introduced to Europe and North America. These crabs are considered an invasive species in their introduced countries, as they are known for causing significant damage by burrowing into riverbanks, competing with native species, and clogging water intake systems. In their native lands they are declining due to overexploitation. They are listed as invasive by the IUCN Invasive Species Specialist Group (ISSG). This article is dedicated to my friend Tony.
First the Stats…
Scientific name: Eriocheir sinensis
Weight: Up to .6 lb.
Length: Up to 4 inches, with up to an 8 inch leg span
Lifespan: Up to 5 years
Now on to the Facts!
1.) They are classified as 1 of the 100 worst invasive species globally.
2.) Another invasive instance is that they out-compete native crab species for habitat and food.
3.) These crabs are listed as injurious wildlife in the United States.
4.) The import of these crustaceans is strictly forbidden by the entirety of the European Union.
5.) Worms, mussels, snails, dead organic material, fish, and other small crustaceans are all on the menu.
But wait, there’s more on the Chinese mitten crab!
6.) An increase in microplastics pollution has had a dramatic impact on their populations as it affects their metabolism, growth, and oxidative stress response in the liver.
7.) They are catadromous, as they migrate from freshwater to saltwater to breed.
Did you know…?
It was reported in 1995 that people in Greenwich saw these crabs coming out of the River Thames, and in 2014 1 was found in the Clyde, in Scotland. They have also been known to take up residence in swimming pools.
8.) In some locales, these crabs have been found hundreds of miles from the sea!
9.) Various strategies like capturing them as they pile up at dams have proven somewhat effective. The problem occurs when the crabs climb the walls of the dams and over into the rivers behind said dams.
10.) They have exhibited an incredible ability to survive in highly modified aquatic habitats, this includes polluted waters. As is the case with some fish, they can easily handle and take in heavy metals, like cadmium and mercury.
But wait, there’s still more on the Chinese mitten crab!
11.) In circa 2010, a Chinese businessman introduced vending machines to sell these crabs in the subways. The crabs are stored at 41°F, which induces a torpor-like state.
12.) Females can produce up to 1,000,000 eggs in a single season.
13.) Eggs hatch in up to 20 days, but can be longer in colder climates.
14.) Sturgeons, bass, channel catfish, eels, herons, egrets, raccoons, river otters, American minks, and humans all prey on these crabs.
Now a Short Chinese Mitten Crab Video!
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Some source material acquired from: Wikipedia & IUCN
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