The effects of diet and stocking density on cannibalism in 'Cherax destructor'

Cannibalism is a normal and widespread phenomenon among crayfish in both natural and aquacultural environments. Up to 50% of juvenile crayfish are cannibalised (Jones, 1995). The cause of cannibalism is unknown but may reflect issues involving population density, growth rate and specific nutrients absent from the diet. As crayfish grow, they undergo ecdysis (moulting), a process that renders them extremely vulnerable to cannibalism. Therefore, the faster the growth rate, the higher the likelihood of cannibalism. We examine the effects of diet and stocking density on the growth and survival of yabbies ('Cherax destructor'). Juvenile yabbies (240 littermates) were fed a commercial silver perch pellet (Diet 1), Diet 1 supplemented with yabby flesh (Diet 2) or yabby flesh (Diet 3) while housed in indoor aquaria at two stocking densities.