Comparative efficacies of commercially available benzimidazoles against Pseudodactylogyrus infestations in eels

Abstract

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 concen- tration 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 as 100 mg l-', was without effect on Pseudodactylogyrus spp.