The Chinese mitten crab has a light brown, square-shaped carapace (shell) can reach width of up to 10 centimeters and features four lateral spines. Males have a V-shaped abdomen, while females have a U-shaped abdomen. The crab's legs are twice as long as the width of its shell, and its hairy, white-tipped claws resemble mittens. It has a distinctive notch located between its eyes.


This crab is omnivorous, feeding on aquatic plants, algae, detritus, fish eggs and marine invertebrates.


Common predators include fish, frogs and birds.

Reproduction and Life Cycle

The catadromous species migrates into saltwater environments in order to reproduce, with males arriving to mating territories first. Females lay between 250,000 and 1 million eggs that adhere to part of her abdomen. Over the winter, females remain under deep water as the eggs develop. Once eggs hatch, larvae (called zoea) spend one to two months in brackish water before migrating upstream to develop into adults.

Did You Know?

  • The Chinese mitten crab is a traditional food source in China, where it supports a large aquaculture industry.
  • Chinese mitten crabs can tolerate a wide range of environmental conditions and, when introduced to a new environment, can spread wide and fast.
  • The effects of mitten crabs on the East Coast are not yet known, because their invasion is a recent one. The first confirmed sighting of a mitten crab in the region occurred in 2005, when a specimen was caught by a commercial waterman in the Maryland portion of the Chesapeake Bay.
  • The Chinese mitten crab is the only crab found in the fresh waters of North America.
  • If you see this invasive species, report it to the Mitten Crab Watch.

Sources and Additional Information