Chitinolytic Bacterial Shell Disease of Shrimp and Prawns

Category

Category 4 (Negligible Regulatory Significance in Canada)

Common, generally accepted names of the organism or disease agent

Chitinolytic bacterial disease, Shell disease, Brown spot disease, Black spot disease, Burned spot disease, Rust disease.

Scientific name or taxonomic affiliation

Chitinolytic bacteria (Gram negative rods) including Vibrio spp. (=Benekea spp.), Pseudomonas spp., Aeromonas spp., Spirillum, spp. and Flavobacterium spp.

Geographic distribution

Ubiquitous, especially evident on shrimp held in long term captivity/culture.

Host species

Numerous species of wild and cultured marine and freshwater shrimps, also lobsters, and many species of crabs and crayfish.

Impact on the host

The exoskeleton becomes pitted, eroded, and melanized at the site of infection.

Diagnostic techniques

Gross Observations: Erosion of chitin demarked by dark brown to black pigmentation demonstrates chitinolysis.

Histology: Progressive necrosis, inflammation and subsequent melanization of the body surface and appendages.

Culture: Culture lesion on marine agar. Test isolated bacteria for chitinolytic activity in saline solution with thin chitin strips.

Methods of control

No known treatment. Shell disease can be managed in captive and cultured populations by reducing crowding, wound avoidance, proper husbandry, and system hygiene.

References

Brock, J.A. 1988. Black spot disease of Macrobrachium. In: C.J. Sindermann and D.V. Lightner (eds.). Disease Diagnosis and Control in North American Aquaculture. Developments in Aquaculture and Fisheries Science 17. Elsevier, Amsterdam, p. 151-153.

Brock, J.A. and D.V. Lightner. 1990. Diseases of Crustacea. Diseases caused by microorganisms. In: O. Kinne (ed.). Diseases of Marine Animals. Volume III: Introduction, Cephalopoda, Annelida, Crustacea, Chaetognatha, Echinodermata, Urochordata. Biologische Anstalt Helgoland, Hamburg, p. 304-309.

Lightner, D.V. 1988. Bacterial shell (brown spot) disease of penaeid shrimp. In: C.J. Sindermann and D.V. Lightner (eds.). Disease Diagnosis and Control in North American Aquaculture. Developments in Aquaculture and Fisheries Science 17. Elsevier, Amsterdam, p. 48-51.

Tonguthai, K. 1992. Diseases of the freshwater prawn Macrobrachium rosenbergii in Thailand. In: M. Shariff, R.P. Subasinghe and J.R. Arthur (eds.). Diseases in Asian Aquaculture. I. Fish Health Section, Asian Fisheries Society. Manila, Philippines, p. 89-95.

Citation Information

Bower, S.M., McGladdery, S.E., Price, I.M. (1994): Synopsis of Infectious Diseases and Parasites of Commercially Exploited Shellfish: Chitinolytic Bacterial Shell Disease of Shrimp and Prawns.

Date last revised: Fall 1994
Comments to Susan Bower

Date modified: