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 branchiobdellid cocoons were observed in the crayfish found dead in Orvenco creek.Hyaline and dematiaceous hyphomycetes were frequently observed and Fusarium spp. and Saprolegnia sp. were isolated from cuticular lesions.Mortalities occurred in two tanks, after 2 and 4 weeks respectively, in the adult crayfish coming from Bidente River utilized for breeding, with approximately a 23.5% cumulative mortality rate. In both cases the crayfish were weak, anorexic and lethargic. Bull. Fr. Pêche Piscic. (2006) 380-381 : 1271-1290 -1272 -Four and eight moribund samples respectively, coming from the two breeding tanks in which the mortalities occurred, underwent examination. In the first case the mortalities were attributed to Thelohania-like organisms and in the second case the mortalities were associated with enteric bacteria Citrobacter freundii.Key-words: white-clawed crayfish, Austropotamobius pallipes complex, diseases, Northern Italy. INVESTIGATIONS PRÉLIMINAIRES SUR LES PATHOLOGIES DES ÉCREVISSES À PATTES BLANCHES AUSTROPOTAMOBIUS PALLIPES COMPLEX DANS DES COURS D'EAU DU NORD DE L'ITALIE RÉSUMÉ

Twenty-eight freshwater crayfish were collected from 8 streams and one small lake in the province of South Tyrol (North Italy) from autumn 1999 to spring 2001, in order to investigate the presence of branchiobdellidans. At 6 of the streams the white clawed crayfish (Austropotamobius pallipes italicus) was collected, while the noble crayfish (Astacus astacus), the exotic species: signal crayfish (Pacifastacus leniusculus) and spiny-cheek crayfish (Orconectes limosus) were respectively caught at the other 2 streams and at the lake. Except for O. limosus, branchiobdellidans were observed on all crayfish examined. On noble crayfish, specimens of Branchiobdella italica and Branchiobdella hexodonta were found on the same host. Branchiobdella italica was largely recovered from all white clawed crayfish. The specimens of signal crayfish were found to carry only Xironogiton victoriensis.Key-words : Branchiobdellidae, freshwater crayfish, annelids, North Italy. Bull. Fr. Pêche Piscic. (2002) LES ESPÈCES DE BRANCHIOBDELLIDAE (ANNELIDA) OBSERVÉES SUR LES ÉCREVISSES DANS LE SUD TYROL (ITALIE DU NORD). RÉSUMÉA partir de l'automne 1999 jusqu'au printemps 2001 en Tyrol du Sud, 28 écrevisses ont été prélevées dans 8 ruisseaux et un petit lac dans le but de vérifier la présence des Branchiobdellidae. L'écrevisse à pieds blancs (Austropotamobius pallipes italicus) a été trouvée dans 6 ruisseaux, l'écrevisse à pieds rouges (Astacus astacus) et l'écrevisse de Californie (Pacifastacus leniusculus) dans deux ruisseaux et l'écrevisse américaine (Orconectes limosus) dans le lac. A l'exclusion de l'écrevisse américaine, on a trouvé chez toutes les autres espèces des Branchiobdellidae. Chez l'écrevisse à pieds rouges, Branchiobdella italica et Branchiobdella hexodonta sont présentes. Chez toutes les écrevisses à pieds blancs, on a relevé une grande quantité de B. italica alors que chez les écrevisses de Californie on a retrouvé seulement le Xironogiton victoriensis. Mots-clés :Branchiobdellidae, écrevisse, Annelida, Italie du Nord.

The acute toxicity of three synthetic pyrethroids (Cypermethrin, Deltamethrin and Cyfluthrin) to red swamp crayfish (Procambarus clarkii) and the mortality after long-term exposition of young common carp to Deltamethrin were determined in standardized laboratory tests.The aim of this study was to evaluate the possibility of limiting the expansion of crayfish by the use of these compounds and the implications of their use on fish.Red swamp crayfish experienced high sensitivity to pyrethroids as expressed by the LC50-24h: 0.14 µg/l for Cypermethrin, 0.17 µg/l for Cyfluthrin and 0.22 µg/l for Deltamethrin. No mortality was observed in common carp during the long term (24 days) exposure test at initial concentration of 22.0 µg/l of Deltamethrin. The concentrations of Deltamethrin in muscle of crayfish and common carp were under the limit of quantification of the gas-chromatographic method in all the tests.The results suggest that synthetic pyrethroids may be suitable to control or to eradicate nuisance populations of red swamp crayfish, in small and limited areas.Key-words: red swamp crayfish, Procambarus clarkii, common carp, Cyprinus carpio, pyrethroids, toxicity. Les écrevisses rouges de marais ont manifesté une sensibilité élevée aux pyréthroïdes, comme l'exprime le LC50-24h : 0,14 µg/l pour la cyperméthrine, 0,17 µg/l pour la cyfluthrine et 0,22 µg/l pour la deltaméthrine. On n'a observé aucune mortalité de carpe commune lors de l'essai avec une longue période d'exposition (24 jours) à la concentration initiale de 22,0 µg/l de deltaméthrine. Les concentrations de deltaméthrine dans le muscle des écrevisses et dans les carpes communes se trouvaient toujours en dessous de la limite de quantification de la méthode de chromatographie gazeuse. ÉVALUATION DE LA TOXICITÉ DE PYRÉTHROÏDES SYNTHÉTIQUES SUR LES ÉCREVISSES ROUGES DES MARAIS DE LOUISIANE (PROCAMBARUSLes résultats suggèrent que des pyréthroïdes synthétiques peuvent être adoptés pour contrôler ou supprimer des populations nuisibles d'écrevisses rouges de marais dans des zones limitées et localisées.

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