Abstract
BackgroundThe development of pesticide resistance represents a global challenge to food production. Specifically for the Atlantic salmon aquaculture industry, parasitic sea lice and their developing resistance to delousing chemicals is challenging production. In this study, seventeen full sibling families, established from three strains of Lepeophtheirus salmonis displaying differing backgrounds in emamectin benzoate (EB) tolerance were produced and quantitatively compared under a common-garden experimental design. Lice surviving to the preadult stage were then exposed to EB and finally identified through the application of DNA parentage testing.ResultsWith the exception of two families (19 and 29%), survival from the infectious copepod to preadult stage was very similar among families (40-50%). In contrast, very large differences in survival following EB exposure were observed among the families (7.9-74%). Family survival post EB exposure was consistent with the EB tolerance characteristics of the strains from which they were established and no negative effect on infection success were detected in association with increased EB tolerance. Two of the lice families that displayed reduced sensitivity to EB were established from a commercial farm that had previously used this chemical. This demonstrates that resistant alleles were present on this farm even though the farm had not reported treatment failure.ConclusionsTo our knowledge, this represents the first study where families of any multi-cellular parasite have been established and compared in performance under communal rearing conditions in a common-garden experiment. The system performed in a predictable manner and permitted, for the first time, elucidation of quantitative traits among sea lice families. While this experiment concentrated on, and provided a unique insight into EB sensitivity among lice families, the experimental design represents a novel methodology to experimentally address both resistance development and other evolutionary questions in parasitic copepods.
Highlights
The development of pesticide resistance represents a global challenge to food production
Considering the limited number of compounds certified for treatment against sea lice in aquaculture, and the documented emerging resistance of L. salmonis to most of these chemicals, this is a critical situation for the continued development of this industry
Resistance development against diflubenzuron [84] and target-site mutations conferring resistance towards other chitin inhibitors with similar modes of action [85] have been documented in terrestrial arthropod pests, and it is possible that L. salmonis will develop resistance to diflubenzuron and teflubenzuron
Summary
The development of pesticide resistance represents a global challenge to food production. For the Atlantic salmon aquaculture industry, parasitic sea lice and their developing resistance to delousing chemicals is challenging production. In Norway, the world’s largest producer of Atlantic salmon (Salmo salar L., 1758), annual production has grown from 98 tonnes in 1971 [1], to over 1.2 million tonnes in 2012 [2]. This rapid development has been met with a number with declines of wild salmonid populations in Europe [17,18] and North America [19,20].
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
