Sodium chloride against Dawestrema cycloancistrium in juvenile Arapaima gigas

The aim of the present study was to assess use sodium chloride (NaCl) against monogenoid trematodes infestations in pirarucu (Arapaima gigas). Two assays were conducted with juveniles, first comprising an vitro exposure 8, 9, 10, and 11 g·L−1 NaCl second, vivo test at same concentrations. best results observed for 1-h exposures NaCl, resulting 60% 100% parasite mortality, respectively. In 8 10 36 22% efficient, respectively, following 2 h exposure, no mortality. Some dose-dependent changes exposed fish, such as decreased hemoglobin MCHC values highest concentration compared other concentrations control group. Most frequent gill tissue alterations capillary dilatation mucus secretions group (10 g·L−1). Decreased mean (p < 0.05) water pH increased electrical conductivity noted conclusion, our findings suggest that exhibits low toxicity toward without physiological anthelmintic activity directly influenced by time concentration. Moreover, monogenoids gills fish identified Dawestrema cycloancistrium.