First records of Eriocheir sinensis H. Milne Edwards, 1853 (Crustacea: Brachyura: Varunidae) for Chesapeake Bay and the mid-Atlantic coast of North America

We report here the first Chinese mitten crabs, Eriocheir sinensis H. Milne Edwards, 1853, found in the Chesapeake Bay, USA. Two male specimens were caught, retained, and identified from the mouth of the Patapsco River, near Baltimore, Maryland. The first crab to be reported was captured on 9 June 2006. Surprisingly, the second reported crab was captured at least one year earlier, probably in May 2005. Another two specimens of E. sinensis were reported up to 90km south of this location in April-June 2006, but the identity of these latter crabs could not be confirmed, because the specimens were not kept. Environmental conditions in Chesapeake Bay appear suitable for colonization by E. sinensis, and it is presently not known whether mitten crabs are reproducing or established in the region.