Common Name Chinese Mitten Crab

Scientific Name Eriocheir sinensis (Milne-Edwards, 1854)

Status Not yet in Cape Breton Description

• light brown, hairy claws with white tips which looks like the crab is wearing “mittens”
• light brown to olive green in color
• smooth round carapace with length up to 100mm
• 4 triangular teeth or spines on each side of carapace
• notch between eyes
• legs approximately twice the length of the carapace width
• for a good image of the "mittens", visit the Chinese Mitten Crabs website

Habitat The Chinese mitten crab is catadromous, with young spending 2-5 years upstream in freshwater tributaries and then migrating downstream to reproduce in salt water (usually estuaries). This unique quality of occurring in both fresh and salt waters makes it the only crab found in the fresh waters of North America. The mitten crab has also been found to tolerate a wide range of temperatures and environmental conditions, such as polluted waters. It can also travel over dry land.

Invasion History The Chinese mitten crab is native from southern China to the Korean Peninsula. In 1912, the first record of the mitten crab was recorded in Europe and during the 1920s and 1930s it invaded, and spread rapidly throughout all of the major rivers in Europe. In the United States, the Chinese mitten crab was first recorded in the Detroit River at Windsor, Ontario in 1965. Since then, the only known established population of mitten crabs is in the San Francisco Bay area and there have been reports, but no establishments in the Mississippi River, the Great Lakes, the St. Lawrence River, and the Columbia River, with the most recent reports being in the Chesapeake Bay (2005-2007) and the Delaware Bay (2007). Regional Sightings The Chinese mitten crab has not yet been reported in Nova Scotia, however, regional biologists are on the alert! Potential Impacts The Chinese mitten crab can have a number of effects on freshwater and estuarine ecosystems. It has an opportunistic diet including algae, detritus, and a variety of macroinvertebrates. After a successful invasion event, it has the potential to both eat and out-compete native species. In addition, juvenile mitten crabs form dense colonies and create burrows in streams, which can affect the stability of the stream banks. For additional human impacts (e.g. economic and health impacts), please visit the Global Invasive Species Database. Additional websites related to Chinese mitten crabs

• Detailed information about Chinese mitten crab - from the Global Invasive Species Database
• Good photos of the Chinese mitten crab and its "mittens"- from the Natural History Museum, London, UK
• How to Identify a Mitten Crab - from the Pacific States Marine Fisheries Commission
• Mitten Crabs: Oriental Invaders of the River Thames- an interesting document about research on the mitten crab in London, UK
• Fishermen fear a mitten crab invasion- an article about mitten crabs in the Hudson River from the Times-Herald Record Online
• ALERT! Eleventh Chinese Mitten Crab found in the mid-Atlantic - Salem Sound Coastwatch
• Mitten Crab Network Newsletter (February 2008) - Fifth Mitten Crab in Chesapeake Bay and Third Chinese Mitten Crab in Hudson River
• Pictures and news archives for the mitten crab - from the Marine Invasions Research Lab (Smithsonian Environmental Research Center)
• Aquatic Alien 'Thugs' to Meet - BBC Science News (good video footage of Chinese Mitten Crab and Signal Crayfish from UK experts)

If you think you have found a Chinese mitten crab in our local waters, please contact us at info@ProjectUFO.ca.