Baculovirus of Blue Crayfish

Category

Category 3 (Host Not in Canada)

Common, generally accepted names of the organism or disease agent

Baculovirus of blue crayfish, Hepatopancreatic baculovirus of cherax, Cherax baculovirus (CBV).

Scientific name or taxonomic affiliation

Nonoccluded Baculoviridae possibly of subgroup C.

Geographic distribution

Australia and in second generation crayfish from Australia that were reared in tanks in California, USA.

Host species

Cherax quadricarinatus.

Impact on the host

In Australia, although 52% of the crayfish examined were infected, there was no clinical disease observed. In a closed tank system in California, growth was poorer than expected but mortality was not greater than what was normal for animals reared in the system being used.

Diagnostic techniques

Histology: Infection appears to be confined to the epithelial cells of the hepatopancrease. Infected hepatopancreatic epithelial cell have irregularly shaped hypertrophied nuclei (up to 2.5 times normal size) that contain amorphous, eosinophilic inclusion material. Occasionally nucleolar remnants are apparent and some inclusions appear to have shrunk away from the nuclear membrane leaving a clear zone with fine basophilic strands radiating from the edge of the inclusion to the chromatin margin. The infection is often focal with several hypertrophied nuclei present in some tubules while adjacent tubules are normal.

Electron Microscopy: Nuclei of infected cells contain numerous rod-shaped non-occluded nucleocapsids (34-47 nm × 154-216 nm) and/or mature enveloped virons (102-172 nm × 220-292 nm). Like other crustacean baculoviruses, the envelope around the helical nucleocapsid has a cap handle appearance. However, this feature seems to be more highly accentuated for the baculovirus in blue crayfish.

Methods of control

No known methods of prevention or control.

References

Anderson, I.G. and H.C. Prior. 1992. Baculovirus infections in the mud crab, Scylla serrata and a freshwater crayfish, Cherax quadricarinatus, from Australia. Journal of Invertebrate Pathology 60: 265-273.

Groff, J.M., T. McDowell, C.S. Friedman and R.P. Hedrick. 1993. Detection of a nonoccluded baculovirus in the freshwater crayfish Cherax quadricarinatus in North America. Journal of Aquatic Animal Health 5: 275-279.

Citation Information

Bower, S.M., McGladdery, S.E., Price, I.M. (1994): Synopsis of Infectious Diseases and Parasites of Commercially Exploited Shellfish: Baculovirus of Blue Crayfish.

Date last revised: Fall 1994
Comments to Susan Bower

Date modified: