Virus-Like Infection of Scallops


Category 4 (Negligible Significance in Canada) Rational: no pathology associated with infection.

Common, generally accepted names of the organism or disease agent

Virus-like particles.

Scientific name or taxonomic affiliation

Baculovirus-like particles in one epithelial cell of the digestive gland of a clinically healthy scallop.

Geographic distribution

Abashiri waters of Hokkaido, Japan.

Host species

Patinopecten yessoensis.

Impact on the host

Virus-like particles were observed in one epithelial cell of the digestive gland of a clinically healthy scallop during a study on the relationship of histological structures in digestive diverticula to nutrient accumulation.

Diagnostic techniques

Electron Microscopy: Several layers of roughly parallel, rod-shaped virions in fence-like arrays. Each virion had a nucleocapsid with a unit membrane envelope and was reminiscent of baculoviruses in morphology. The average length and diameter of the virions were 520 and 130 nm, respectively. The average thickness of the envelope was 12 nm and the average distance between the envelope and the nucleocapsid was 10 nm. No occlusion bodies were observed. The only other abnormality in the infected cell was a great number of small (520 to 1050 nm in diameter), double-membrane vacuoles that appeared to be a network of proliferated, tubular smooth endoplasmic reticulum among the virions.

Methods of control

No known methods of prevention or control.


Chang, Y.J., M.-D. Huh, M.-J. Oh and Y. Sugawara. 2002. Baculovirus-like particles in epithelial cell of digestive diverticula of the scallop, Patinopecten yessoensis. Journal of Shellfish Research 21: 109-112.

Citation Information

Bower, S.M. (2004): Synopsis of Infectious Diseases and Parasites of Commercially Exploited Shellfish: Virus-Like Infection of Scallops.

Date last revised: May 2004
Comments to Susan Bower

Date modified: