Description of a hepatopancreatic rickettsia-like organism in the redclaw crayfish Cherax quadricarinatus

Basophilic, Gram-negative, microcolonies of rickettsia-like organisms were observed in the hepatopancreatic tubule epithelium of 1 moribund Cherax qua dricarinatus from a farm in north Queensland. The tissue tropism of the org anism is distinct from the systemic rickettsia-like organism previously des cribed from C, quadricarinatus. This paper briefly describes the histopatho logy, cytopathology and basic morphology of the hepatopancreatic rickettsia -like organism.