Trematode Metacercariae in Lobsters


Category 4 (Negligible Regulatory Significance in Canada)

Common, generally accepted names of the organism or disease agent

Trematode larvae in lobsters.

Scientific name or taxonomic affiliation

Stichocotyle nephropis.

Geographic distribution

a) Eastern Canada and south off Cape Cod.
b) Scotland

Host species

a) Homarus americanus.
b) Nephropis norvegicus.
Note: Metacercariae of other species of trematodes have been reported from many species of crabs.

Impact on the host

The biology of this trematode is poorly known but adults occur in the bile duct and intestine of skates and rays. Prevalence is low in eastern Canada (less than 2%) but up to 35% of N. norvegicus were found infected in the Firth of Forth, Scotland.

Diagnostic techniques

Squash Preparations: Larval trematodes occur in the intestine.

Methods of control

No known methods of prevention or control.


Brattey, J. and A. Campbell. 1986. A survey of parasites of the American lobster, Homarus americanus (Crustacea: Decapoda), from the Canadian Maritimes. Canadian Journal of Zoology 64: 1998-2003.

Herrick, F.H. 1911. Natural history of the American lobster. Bulletin of the Bureau of Fisheries 29 (1909): 149-408.

Uzmann, J.R. 1970. Use of parasites in identifying lobster stocks. The Journal of Parasitology 56: 349. (abstract).

Citation Information

Bower, S.M. (1996): Synopsis of Infectious Diseases and Parasites of Commercially Exploited Shellfish: Trematode Metacercariae in Lobsters.

Date last revised: September 1996
Comments to Susan Bower

Date modified: