Burn spot disease generally refers to spots, pits or holes in the shells of crustaceans. It’s a problem for both freshwater and marine species and a phenomenon found worldwide. Australian freshwater crayfish are susceptible to the disease and it has been known to cause epidemics and can be of serious concern for aquaculture facilities.

It occurs in the wild and many Euastacus and Cherax species are susceptible to infection. There are over 100 different species of freshwater crayfish in Australia. Go to http://www.aabio.com.au/crayfish-list/ for a full list of all Australian species.

A yabby with "Burn Spot" disease
A yabby with “Burn Spot” disease

I was sent some blue claw yabbies (Cherax destructor) the other day by one of our members and fellow crayfish farmer to identify a disease they had. These yabbies have burn spot disease. The disease is characterized by progressive erosion of the exoskeleton (the hard outer shell or cuticle), typically it starts as a just barely visible dark brown, almost black melanized area on the exoskeleton.(You need to be a member to read the rest of this article and see more photos of the disease) 

In my previous life as a large scale commercial yabby farmer I never came across the disease and hopefully you other yabby farmers also never will. The above pictures are just offered as a guide for what to keep an eye out for. As someone that has never had much to do with the disease I know very little, if anyone has greater knowledge to share, please let me know.