Commercial trials using emamectin benzoateto control sea lice Lepeophtheirus salmonis infestations in Atlantic salmon Salmo salar

Diseases of Aquatic Organisms

R. H. Richards¹  J. Stone¹  K. J. Varma¹  I. H. Sutherland¹  C. Sommerville¹ 

关键词: Sea lice;    Lepeophtheirus salmonis;    Caligus elongatus;    Salmo salar;    Emamectin benzoate;   

DOI  :  10.3354/dao041141

学科分类：生物科学（综合）

来源: Inter-Research

【 摘 要 】

ABSTRACT: Two trials were conducted at commercial salmon farms to evaluate the efficacy of emamectin benzoate (Slice^®, 0.2% aquaculture pre-mix, Schering-Plough Animal Health) as a treatment for sea lice Lepeophtheirus salmonis (Krøyer)and Caligus elongatus Nordmann infestations in Atlantic salmon Salmo salar L. Trials were carried out in 15 m² commercial sea pens, at temperatures of 5.5 to 7.5°C and 10.8 to 13.8°C. Each pen was stocked with 14000 to 17500 fishwith mean weights of 0.44 to 0.74 and 1.33 to 1.83 kg. Fish were naturally infested with sea lice at the start of each trial. At Day -1, samples of 10 or 15 fish were taken from each pen to determine pre-treatment numbers of lice. Emamectin benzoate wasadministered in feed, to 4 replicate pens, at a dose of 50 µg kg^-1 biomass d^-1 for 7 consecutive days (Days 0 to 6). Sea lice were counted again, between Days 7 and 77, and comparisons made with untreated control fish. Despiteadverse weather conditions, wide variations in fish weights and exposure to new infestations, treatment was effective against chalimus and motile stages of L. salmonis. In the autumn trial, efficacy at Day 27 was 89%, and lice numbers remainedlower on treated fish than on control fish 64 d from the start of treatment. In the winter trial, reductions in lice numbers at low temperatures were slower but good efficacy was achieved by Day 35. Although control fish had to be treated with hydrogenperoxide at Day 21, fish treated only with emamectin benzoate on Days 0 to 6 still had 89% fewer lice than control fish at Day 35. There were very few C. elongatus present, but at the end of both trials numbers were lower on treated fish. Noadverse effects were associated with treatment of fish with emamectin benzoate.

【 授权许可】

Unknown