Microsporidiosis of Crayfish

Also Known As: Thelohaniasis of crayfish, Microspordian disease, Porcelin disease, Cotton disease, Milky disease, White tail and Protozoan disease.


General/Background information: This disease is a result of microscopic parasites (microsporidians) infecting freshwater crayfish (though Microsporidia also occur in marine crustaceans). Primarily found in Eurasia, New Zealand and Australia, though there are increasing numbers of reports in the United States.


Signs of the disease: This disease is very difficult to detect in its early stages. It usually becomes noticeable when the coloration in the crayfish's tissues changes. This is most visibly seen in the joints and abdomen, where the tissue becomes white and opaque (much like cooked chicken or fish), instead of the normal, almost translucent coloration. As the disease progresses the infected crayfish become lethargic and anorexic. This disease is ultimately fatal once it has been contracted.




Prophylactic treatment: Don't mix genus or species of crayfish together in the same tank(s). Keep your tank(s) in excellent condition (poor water quality, low oxygen levels, improper and unstable temperatures, improper feeding, etc create stressed animals which become more susceptible to infection).


Treatment: There are no treatments available.


Cure: None currently.


Sources:
www.pac.dfo-mpo.gc.ca/sci/shelldis/pages/thelocy_e.htm
www.fish.wa.gov.au/docs/pub/FHThelohania/index.php?0408

Picture Sources:
Department of Fisheries, Western Australia