CHINESE MITTEN CRAB ALERT
U.S. Atlantic Coast Bays & Rivers
New 2008 Reports: New Jersey & New York
Please Report Any Sightings of This Crab
Mitten Crabs in the Eastern U.S. Live Chinese Mitten Crabs (Eriocheir sinensis) have been found in Chesapeake Bay (2005-2007), Delaware Bay (2007), Hudson River (2007-2008), and most recently in New Jersey (2008). To date, there have been 19 crabs documented and confirmed in the eastern United States, including four states, all in the past four years.
In New Jersey, mitten crabs were found in Toms River (June 1, 2008) and Raritan Bay (June 17, 2008). The Toms River crab is the first confirmed record in the state of New Jersey. The male crab, measuring 50mm, was found crawling on a crab holding pen (peeler pot). The second crab caught in New Jersey was collected by a commercial waterman in the Raritan Bay near Keyport, NJ on June 17, 2008; it has been identified through pictures as an adult mitten crab, sex still unconfirmed. This crab apparently was not the waterman’s first catch, as the species was reportedly observed in the same area at least weekly for the three weeks prior to this catch.
Also in 2008, four other mitten crabs were captured in the Hudson River, New York, including one female (20mm on June 3) and three males (16-26mm from June 9 to July 18). All crabs were caught in freshwater near Tivoli, NY, approximately 100 miles inland along the Hudson River by a research scientist, who was studying eel movement on local tributaries. A total of seven mitten crabs have been confirmed for Hudson River to date.
The Chinese Mitten Crab is native to East Asia, and could have negative ecological and economic impacts. Mitten Crabs are already established invaders in Europe and on the West Coast of the United States. We don’t yet know whether the crab has established reproductive populations in the eastern U.S. The crab is listed as Injurious Wildlife under the Federal Lacey Act, which makes it illegal in the United States to import, export, or conduct interstate commerce of Mitten Crabs without a permit.
Life History. The Chinese Mitten Crab occurs in both freshwater and saltwater. Young crabs spend two-five years in freshwater tributaries and can extend many miles upstream of bays and estuaries. Mature male and female crabs migrate downstream to mate and spawn in saltwater estuaries. Chinese Mitten Crabs burrow into banks and levees along estuaries and are able to leave the water to walk around obstacles while migrating.
Please Report Any New Sightings. To determine the status, abundance, and distribution of this species along the eastern U.S., we have established a Mitten Crab Network. The Network began as a partnership among several state, federal, and research organizations, with an initial focus on Chesapeake and Delaware Bays. We have now expanded the Network to include resource
managers, commercial fishermen, research organizations, and citizens along the eastern U.S. Please help by reporting any mitten crabs directly to the Network or to your state resource manager.
If you catch a mitten crab
- Commonly found in fresh waters of North America, but can occur in saltwater bays and estuaries
- Claws equal in size with white tips and appear furry (with thick mats of hair-like covering on claws)
- If you find a crab, with a carapace length over one inch and no hair on the claws, it is NOT likely to be a Mitten Crab. NOTE: Juveniles under one inch may not have hair on the claws.
- Carapace up to 4 inches wide; light brown to olive green in color
- No swimming legs. This crab has eight sharp-tipped walking legs
- Do not throw it back alive!
- Freeze the animal, keep it on ice, or preserve it in rubbing alcohol as a last resort
- Note the precise location and date where the animal was found
- Please take a close-up photo of the animal. Photos can be emailed to SERCMittenCrab AT si.edu for preliminary identification. Include your contact information with the photo
- If you cannot take a photo, contact the Mitten Crab Hotline (443-482-2222)
REMEMBER THE LAW! Never transport a live Mitten Crab across state boundaries
For additional information please visit http://www.serc.si.edu/labs/marine_invasions/ for updated Mitten Crab reports, downloadable pamphlets on the Chinese Mitten Crab Survey Program, and how to distinguish a Mitten Crab from other crabs