Study on withdrawal period of emamectin benzoate in orally medicated silver carp ( Hypophthalmichthys molitrix )

Abstract

Parasitic diseases have been the major source of concern and cause considerable losses in the freshwater aquaculture of India. Fish parasites proliferate quickly in favourable settings, compromising fish health and frequently resulting in high mortality. Identifying and implementing appropriate control techniques is the need of the hour to combat the diseases. Emamectin benzoate (EMB) is an efficient infeed therapy for ectoparasite control in fish. The aim of the present study was to determine the withdrawal period of EMB in silver carp (Hypophthalmichthys molitrix) commercially important fish species in southeast Asia. The depletion of EMB residues in silver carp muscle treated with a dose of 50 μg kg−1 body weight (BW) day−1 for seven consecutive days was assessed. Muscle tissue was sampled on the 7th day of EMB feeding and 1st‐, 3rd‐, 7th‐, 14th‐, 21st‐, 35th‐ and 41st‐day post‐medication (PM) for QTRAP 4000 LC–MS/MS analysis. The data revealed that the level of EMB in the fish muscle was 13.0 ± 0.1 parts per billion (ppb) on the 0th day of withdrawal. The residue levels were reduced significantly on the 3rd day, with traces of EMB recorded by 21st‐day PM and reached undetectable levels by 31st day PM. Considering the maximum residue limit (MRL) of 100 μg kg−1 for fish muscle, the present study's findings support the usage of EMB in silver carp under the conditions employed in the study. The current study provides crucial information on the use of EMB as an antiparasiticide in silver carp, considering the food safety issues.

Natural infestation of an anchor worm, Lernaea sp. in cage culture of Asian Seabass, Lates calcarifer juveniles and its control using an anti-parasitic drug, emamectin benzoate

“…Because of such restrictions, there was a necessity for new drug with advantages of in-feed administration, high tolerance in sh, effective in wide range of temperatures, capacity to destroy all the life stages of parasites, and protection for an extended period of 10 weeks after treatment with least environmental consequences. Hence, we have identi ed an innovative avermectin, emamectin benzoate (EMB) and studied the biosafety, withdrawal period, environmental safety and e cacy against crustacean parasites in the laboratory condition (Ananda Raja et al 2020; Julinta et al 2020; Kurcheti et al 2022). There was a natural outbreak of lernaeosis in Asian Seabass, Lates calcarifer juvenile in freshwater cage culture, it was treated using EMB and also a wet lab experiment was designed to assess the e cacy of EMB against lernaeosis under controlled condition.…”