Acanthocephalan Parasitism of Crabs


Category 3 (Host Not in Canada)

Common, generally accepted names of the organism or disease agent

Acanthocephalan parasitism of crabs.

Scientific name or taxonomic affiliation

Profilicollis (=Polymorhpus) botulus.

Geographic distribution

Ythan estuary, Scotland.

Host species

Carcinus maenas, also reported from Homarus americanus on the east coast of North America.

Impact on the host

No evidence of pathogenicity to crab hosts in Ythan estuary where 43% of the crabs were infected with 1 to 9 cystocanths with a positive relationship between crab size and the mean number of P. botulus per crab. However, the eider duck (Somateria mollissima) final host of this parasite can accumulate infections of 100-750 P. botulus which have been associated with seasonal "outbreaks" of disease and mortalities in the eider ducks. The cystacanth is long lived and probably remains infective throughout the life of the crab.

Diagnostic techniques

Wet Mounts: Acanthellae and cystocanths with number, arrangement and shape hooks as for adult P. botulus in region immediately under the heart or in the musculature around the mid and hind gut of crabs.

Methods of control

No known methods of prevention or control.


Rayski, C. and E.A. Garden. 1961. Life-cycle of an acanthocephalan parasite of the eider duck. Nature 192: 185-186.

Thompson, A.B. 1985. Transmission dynamics of Profilicollis botulus (Acanthocephala) from crabs (Carcinus maenas) to eider ducks (Somateria mollissima) on the Ythan Estuary, N.E. Scotland. The Journal of Animal Ecology 54: 605-616.

Thompson, A.B. 1985. Analysis of Profilicollis botulus (Acanthocephala: Echinorhynchidae) burdens in the shore crab, Carcinus maenas. The Journal of Animal Ecology 54: 595-604.

Citation Information

Bower, S.M. (1996): Synopsis of Infectious Diseases and Parasites of Commercially Exploited Shellfish: Acanthocephalan Parasitism of Crabs.

Date last revised: September 1996
Comments to Susan Bower

Date modified: