Outbreak of Notozothecium bethae (Monogenea: Dactylogyridae) in Myleus schomburgkii (Actinopterygii: Characiformes) cultured in the Peruvian Amazon

The presence of Notozothecium bethae was investigated in 76 black band myleus (Myleus schomburgkii [Actinopterygii: Charasiformes]) born and kept in captivity in two semi-intensive breeding cages in the northern region of Peru. Among the 76 cultivated specimens of M. schomburgkii examined in the present study, 100 % had monogenean on the gill and the parasites were identified as Notozothecium bethae. During the survey no bacteria was isolated, and no protozoan or other metazoan parasites were found. The prevalence of N. bethae remained constant throughout the present study. Mean intensity of N. bethae in the months of April and May was exceptionally high in both facilities. The massive infection of N. bethae on the gills of M. schomburgkii was associated with mortality. This is the first report of N. bethae in M. schomburgkii born in captivity and cultured in the Amazon region. The mortality due the presence of this parasite emphasise the need for disease control strategies of cultured M. schomburgkii.