Gregarine Parasitism of Lobsters
Category 4 (Negligible Regulatory Significance in Canada)
Common, generally accepted names of the organism or disease agent
Gregarine parasitism of lobsters.
Scientific name or taxonomic affiliation
- Porospora (=Gregarina) gigantea.
- Porospora nephropis.
- East coast of Canada, and the Atlantic and Mediterranean coasts of France.
- Northern part of France.
- Homarus americanus.
- Nephrops norvegicus.
Impact on the host
No gross pathological changes were associated with infection although several hundred gregarines were observed in some lobsters. There may be a seasonal trend in the prevalence of infection which usually exceeds 50% in lobsters with a carapace length more than 50 mm.
Gross Observations: White cysts (0.25-0.5 mm diameter) along the inside walls of the posterior intestine and rectum.
Squash Preparations: Charasteristic spherical gamonocysts (about 300 µm in diameter) attached to the cuticular lining of the rectum, and thread-like trophic stages (up to 16 mm long) found in the lumen of the intestine.
Methods of control
No known methods of prevention or control.
Boghen, A.D. 1978. A parasitological survey of the American lobster Homarus americanus from the Northumberland Strait, southern Gulf of St. Lawrence. Canadian Journal of Zoology 56: 2460-2462.
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.
Sprague, V. 1970. Some protozoan parasites and hyperparasites in marine decapod crustacea. American Fisheries Society Special Publication 5: 416-430.
Théodoridès, J. and M. Laird. 1970. Quelques Eugrégarines parasites d' invertébrés marins de St. Andrews (Nouveau-Brunswick). Canadian Journal of Zoology 48: 1013-1016.
Bower, S.M. (1996): Synopsis of Infectious Diseases and Parasites of Commercially Exploited Shellfish: Gregarine Parasitism of Lobsters.
Date last revised: September 1996
Comments to Susan Bower
- Date modified: