Aquatic invasive species

JAPANESE SKELETON SHRIMP

(Caprella mutica)

Caprella mutica is an amphipod crustacean (such as beach fleas) from eastern Asia. It was first reported in eastern Canada in the 1990's in the Bay of Fundy, and in the Gulf of St. Lawrence (Prince Edward Island) in 2000.

HABITAT

Common on man-made structures such as ropes, buoys, artificial reefs, breakwaters and mussel aquaculture socks. Often very abundant.

Like many invasive species Caprella mutica reproduces rapidly, has a varied diet and tolerates a wide range of temperatures and salinities.

Japanese skeleton shrimp – DFO T. Gosselin
DFO T. Gosselin

CHARACTERISTICS

Japanese skeleton shrimp - SAMS  T. Nickell
SAMS T. Nickell
  • Maximum size: males 3.5 cm and females 1.5 cm;
  • Colour: variable from pale orange to red;
  • Long cylindrical body, males with a long two-segmented neck;
  • Females carry eggs in a ventral (belly) pouch, which is covered with dark red spots;
  • Males very hairy on neck and claws.

SIMILAR SPECIES

There are several native caprellid species that resemble Caprella mutica. However, these species grow mainly on natural substrates and are not hairy.

ECOLOGICAL AND ECONOMIC IMPACTS

  • Infests man-made structures such as buoys and mussel aquaculture socks, sometimes reaching numbers of 100,000 individuals per square meter;
  • May compete with mussels for food and space.

WHAT YOU CAN DO