Aquatic invasive species

CHINESE MITTEN CRAB

(Eriocheir sinensis)

The Chinese mitten crab, native to the Yellow sea between China and Korea, is one of the ten most unwanted species in the world. It was first reported in the Great Lakes in 1965 where it occasionally shows up in Lakes Ontario and Erie. It appeared in the St. Lawrence River in 2004. No freshwater crab species existed in North America before its arrival.

HABITAT

It can be found down to a depth of ten meters, in fresh or brackish waters in estuaries, lakes, rivers and wetlands. It can tolerate a wide range of temperatures and salinities and can easily survive in disturbed and polluted environments. It is a catadromous species that lives in freshwater and reproduces in saltwater.

Chinese mitten crab - MRNF  G. Bourget
MRNF G. Bourget

CHARACTERISTICS

Chinese mitten crab - SERC  G. Ruiz
SERC G. Ruiz
  • Adult size: 3 to 8 cm;
  • Colour: greenish brown;
  • Shell with a notch between the eyes and four spines on either sides;
  • Two claws of the same size with white tips and dense fluffy hair (the adults seem to be wearing mittens);
  • Legs twice as long as the carapace width.

SIMILAR SPECIES

No native species have hairy claws.

ECOLOGICAL AND ECONOMIC IMPACTS

Chinese mitten crab - DFG, Ohio State, USA
DFG, Ohio State, USA
  • Accelerates river bank erosion by burrowing;
  • Population expansion may occur in the St. Lawrence River which has appropriate environmental conditions;
  • May compete with and prey on native species.

WHAT YOU CAN DO

  • Learn how to recognize Chinese mitten crab;
  • DO NOT RELEASE THE CRAB;
  • Capture it and freeze it; destroy it, if possible.
  • Follow the general guidelines.