Mebendazole dietary supplementation controls Monogenoidea (Platyhelminthes: Dactylogyridae) and does not alter the physiology of the freshwater fish Colossoma macropomum (Cuvier, 1818)

This study evaluated the efficacy of mebendazole treatment in supplemented diet against the monogeneans Anacanthorus spathulatus, Notozotecium janauachensis and Mymarothecium boegeri gill parasites of an important native farmed characid fish Colossoma macropomum as well as its effect on the fish physiology. Fish were fed supplemented diet with 0, 0.5, 1.0 and 2.0 g mebendazole (MBZ)·kg-1 dry ration for 14 days. Parasitological analysis and blood collection were performed at 7 and 14 days after feeding. Anacanthorus spathulatus was more resistant to than N. janauachensis, and M. boegeri was more sensitive to treatment. On the other hand, good results in terms of disease control were found when analyzing the parasitological index (prevalence, mean intensity and mean abundance) and the fish physiological response. Fish fed 1.0 g MBZ·kg-1 dry ration for 14 days showed 89.2% of efficacy. Mebendazole treatment did not affect the glucose, hemoglobin, red blood cells count, sodium and potassium concentrations. Furthermore, has proved to be effective in controlling monogenea parasites in C. macropomum. Statement of relevance: Colossoma macropomum commonly known as tambaqui or cachama is one of the most native farmed characid fish in South America. North of Brazil has the main tambaqui production, however obstacles interfere in the fish health like ectoparasites. Besides the best management practices, alternative treatments must be pointed out to keep the homeostasis of the host under parasite infestation. This study focused the treatment of monogenean helminth parasites in the gills of C. macropomum and its effects on the hematological parameters and plasma ions. © 2016 Elsevier B.V