Japanese Skeleton Shrimp
Caprella mutica

The Japanese Skeleton Shrimp is an amphipod crustacean (such as beach fleas) from eastern Asia.

Report a discovery in an unlisted area

If you think you’ve seen or caught a Japanese Skeleton Shrimp:

  • Do not release it into the water.
  • Catch it and keep it frozen. If you can’t do that, destroy it.
  • Note the location (with GPS coordinates if possible) as well as the observation date.
  • Contact Fisheries and Oceans Canada.

Identifying features

Similar species (native)

There are several native caprellid species that resemble the Japanese Skeleton Shrimp. However, these species grow mainly on natural substrates and are not hairy.

Japanese Skeleton Shrimp distribution in Gulf region

Japanese Skeleton Shrimp distribution in Gulf region
Click image to enlarge

Where it has been found

It was first reported in eastern Canada in the 1990's in the Bay of Fundy, and was then reported in Prince Edward Island in 1998, in Quebec in Chaleur Bay in 2003 and recently on the coasts of British Columbia. It is also present on the Gulf shore of Nova Scotia as well as the northeastern shore of New Brunswick.


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

Like many invasive species Japanese Skeleton Shrimp reproduces rapidly, has a varied diet and tolerates a wide range of temperatures and salinities.

Ecological and economic impacts

Ecological threats

Despite the introduction of Japanese Skeleton Shrimp in several countries.

Few direct or indirect impacts have been observed fallowing the Japanese Skeleton Shrimp introduction in several countries. As this species abundance is higher during the summer, it would be more likely to observe its impact during this season.

Socioeconomic threats

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

Origins and mode of arrival

Native from eastern Asia

The transport of organisms for aquaculture and by ballast waters are identified as the most plausible vectors of introduction in North America.

Click image to enlarge.

Distribution Location and Bay

Bar Haven: Placentia Bay

Bay East: Fortune Bay

Big Southwest Cove: Placentia Bay

Burin: Placentia Bay

Darbys Harbour: Placentia Bay

Fox Harbour: Placentia Bay

Foxtrap: Conception Bay

Jean de Gaunt: Placentia Bay

Little Bay: Placentia Bay

Paradise Sound: Placentia Bay

Petite Forte: Placentia Bay

Port aux Basques: Southwest Coast

Presque Harbour: Presque Harbour:

Salmonier Cove: Salmonier Cove:

Government action

Scientific research

Fisheries and Oceans Canada is studying the Japanese Skeleton Shrimp population to improve its understanding of how it reacts and adapts to Canadian conditions and to follow the species distribution in St. Lawrence River.

For further information


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