PRELIMINARY INVESTIGATIONS OF DISEASE-CAUSING ORGANISMS IN THE WHITE-CLAWED CRAYFISH AUSTROPOTAMOBIUS PALLIPES COMPLEX FROM STREAMS OF NORTHERN ITALY

A total of 99 live and 3 dead white-clawed crayfish Austropotamobius pallipes complex were collected during the summer and autumn of 2003 from one creek in Emilia Romagna region and four watercourses in Friuli Venezia Giulia region (Northern Italy) for experimental breeding and health status monitoring. Fifty-one animals from the Bidente River were maintained in tanks for breeding, and restocking, while another 30 specimens (27 living and 3 dead) were examined in the laboratory to evaluate their health status. Parasitological surveys were carried out on gills; mycological examinations on the exoskeleton (the walking legs and the abdomen); bacteriological examinations of inoculations from the haemolymph, and histopathological analysis on full transverse and sagittal sections of cephalothorax and abdomen. In the branchial-chambers, the gill filaments and the exoskeleton were observed for ectocommensal peritrich protozoans Epystilis spp. and Cothurnia sieboldii. In crayfish sampled from five streams and rivers, Branchiobdella italica, B. astaci, B. parasita and B. hexodonta were isolated. Heavily damaged gills in the presence of branchiobdelli