Depletion of praziquantel in muscle tissue and skin of cultured rockfish ( Sebastes schlegeli) under the commercial culture conditions

Abstract

Depletion of praziquantel in muscle tissue and skin of cultured rockfish ( Sebastes schlegeli) under the commercial net-pen farm conditions was analyzed. The levels of praziquantel were determined after the administration of three doses of either praziquantel 200 or 400 mg/kg of body weight (bw) given at 24-h intervals. Fish were collected daily following last drug administration and analyzed for praziquantel in muscle tissue and skin by reversed-phase high-performance liquid chromatography (RP-HPLC) using diazepam as an internal standard. In the group of fish fed 200 mg of praziquantel/kg bw, praziquantel was detected in muscle tissue until 1 day and in skin until 3 days post treatment. Following treatment with 400 mg of praziquantel/kg bw, praziquantel was found in muscle tissue and skin until 5 and 6 days post treatment, respectively. In both muscle tissue and skin, the praziquantel concentrations were consistently declined with the lapse of time.