Marteilia sp. of Scallops


Category 1 (Not Reported in Canada)

Common, generally accepted names of the organism or disease agent

Marteilia sp. of calico scallops.

Scientific name or taxonomic affiliation

Marteilia sp. that closely resembles Marteilia refringens of oysters and mussels.

Geographic distribution

East coast of Florida.

Host species

Argopecten gibbus.

Impact on the host

This parasite has been implicated in mass mortalities approaching 100% of the calico scallop population off Florida (i.e. the fishery that produced 11-40 million pounds of adductor muscle meats annually prior to December 1988 was destroyed within one month over a 2500 square mile area). As of the spring of 1992, the scallops had not returned to harvestable quantities. Marteilia sp. filled the tubules of the digestive gland, reducing nutrient acquisition and causing starvation and wasting with rapid mortalities.

Diagnostic techniques

Histology: Cross sections of the digestive gland were occluded with Ascetospora that resemble Marteilia refringens.

Methods of control

No known methods of prevention or control. Avoid movement of all bivalves out of the endemic area.


Blake, N.J. and M. Moyer. 1992. Mass mortality of calico scallops, Argopecten gibbus, resulting from an ascetosporan infection. p. 280 In Abstract, Society for Invertebrate Pathology XXV Annual Meeting, August 16­21, Heidelberg, Germany.

Moyer, M.A. and N.J. Blake. 1991. Mass mortality in the calico scallop, Argopecten gibbus, caused by Marteilia sp. 8th International Pectinid Workshop, Cherbourg, France. Fisheries Section.

Moyer, M.A., N.J. Blake and W.S. Arnold. 1993. An acetosporan disease causing mass mortality in the Atlantic calico scallop, Argopecten gibbus (Linnaeus, 1758). Journal of Shellfish Research 12: 305-310.

Citation Information

Bower, S.M., McGladdery, S.E., Price, I.M. (1994): Synopsis of Infectious Diseases and Parasites of Commercially Exploited Shellfish: Marteilia sp. of Scallops.

Date last revised: Fall 1994
Comments to Susan Bower

Date modified: