Evaluations of Lethal and Sub-lethal Toxicity of Febantel in the Juvenile Japanese Amberjack <i>Seriola quinqueradiata</i>

Recent studies have shown efficacy of febantel (FBT) against Microsporidium seriolae in Seriola fish. ​This study evaluated the toxicity FBT quinqueradiata. ​Fish were gavage fed with feed containing various doses (50 to 1,000 mg/kg/day (d)) for 14 or 28 consecutive days and monitored growth survival. ​Major mortality started at 7 fish given 200 mg/kg/d FBT, while onset 50 100 groups was delayed until 15 days. ​Doses higher affected growth. ​Histological analyses revealed changes distribution density Nissl bodies brain, a reduction vacuolies hepatocytes. ​These histological rarely observed after 9-day drug washout period, suggesting that such reversible. ​There no drug-related received 20 results suggest that, although can lethal S. quinqueradiata when administrated over more than days, is considered safe normal antiparasitic dose, including effective dose M. treatment (10 5 days).