Efficacy of emamectin benzoate in the control of Argulus coregoni (Crustacea: Branchiura) on rainbow trout Oncorhynchus mykiss

Diseases of Aquatic Organisms

T. Hakalahti¹  Y. Lankinen¹  E. T. Valtonen¹ 

关键词: Emamectin benzoate;    Slice;    Argulus coregoni;    Ectoparasite;    Control;   

DOI  :  10.3354/dao060197

学科分类：生物科学（综合）

来源: Inter-Research

【 摘 要 】

ABSTRACT: Efficacy of in-feed treatment with emamectin benzoate (Slice) for the control of ectoparasitic Argulus coregoni on rainbow trout Oncorhynchus mykiss was tested under laboratory and field conditions. In both experiments fish werefed with fish feed to deliver a therapeutic dose of 0 (control) or 50 µg emamectin benzoate kg^–1 d^–1 (treatment) for a period of 7 d. After 3 d of challenge with A. coregoni in the laboratory, the infestationlevel in treated fish was lower than that observed in the controls (p < 0.001). Efficacy of 100% against newly hatched A. coregoni metanauplii and adults and 80% against juveniles was observed. In the field, trial medication was undertaken at 2sections on a flow-through canal with 1 wk between treatments. Mean infestations of 100 to 200 A. coregoni per fish with 100% prevalence was recorded prior to medication. Following the treatment, the mean infestation of A. coregoni on fishdeclined to 31 lice per fish at Section A and 2.5 lice per fish at Section B. Then, after 28 d of treatment, the number of lice per fish was <1 at Section A; in contrast the mean number of A. coregoni per fish at the control section was >20.The prevalence of A. coregoni remained <50% over a period of 72 d of treatment, but started to increase again thereafter. This suggests that emamectin benzoate concentration in fish remained at a level high enough to kill A. coregoni overa period of 9 wk. Emamectin benzoate was very effective in the control of A. coregoni infesting trout.

【 授权许可】

Unknown