Comparative efficacies of commercially available benzimidazoles against Pseudodactylogyrus infestations in eels

The antiparasitic efficacies of 9 benzimidazoles in commercially avalable formulations were tested (water bath treatments) on small pigmented eels Anguilla anguilla, expenmentally infected by 30 to 140 specimens of Pseudodactylogyrus spp.(Monogenea).Exposure time was 24 h and eels were examined 4 to 5 d post treatment.Mebendazole (Vermox; 1 mg 1-') eradicated all parasites, whereas luxabendazole (pure substance) and albendazole (Valbazen) were 100 % effective only at a concentration of 10 mg I-'.Flubendazole (Flubenol), fenbendazole (Panacur) and oxibendazole (Lodltac) (10 mg l-') caused a reduction of the infection level to a larger extent than did triclabendazole (Fasinex) and parbendazole (Helmatac).Thiabendazole (Equizole), even at a concentration as high a s 100 mg l-', was without effect on Pseudodactylogyrus spp.