A compendium of idiopathic lesions observed in redclaw freshwater crayfish, Cherax quadricarinatus (von Martens)

Idiopathic lesions observed in redclaw freshwater crayfish, Cherax quadricarinatus (von Martens), from farms in northern Queensland, Australia, over a 4-year period are described. Various idiopathic lesions were observed in the exoskeleton, antennal gland, mandibular organ, haemolymph vessel endothelium and enteric tissues of C. quadricarinatus collected for histopathological surveys, investigations of chronic mortalities or during other activities. The need for an increased use of histopathology in crayfish disease diagnosis is highlighted.