title: Early-stage sea lice recruits on Atlantic salmon are freshwater sensitive.
abstract: Sea lice are significant parasites of marine and brackish farmed fishes. Freshwater bathing is a potential control option against numerous sea lice species, although has been viewed as futile against those that are capable of tolerating freshwater for extended periods. By comparing freshwater survival times across host-attached stages of Lepeophtheirus salmonis (Krøyer), a key parasite in Atlantic salmon farming, we show the first attached (copepodid) stage undergoes 96-100% mortality after 1 h in freshwater, whereas later attached stages can tolerate up to 8 days. Thus, regular freshwater bathing methods targeting the more susceptible attached copepodid stage may successfully treat against L. salmonis and potentially other sea lice on fish cultured in marine and brackish waters.
authors.affiliation: Sustainable Aquaculture Laboratory - Temperate and Tropical, School of BioSciences, University of Melbourne, Melbourne, Vic., Australia.
authors.forename: D W
authors.initials: DW
authors.lastname: Wright
authors.affiliation: Institute of Marine Research, Matre, Norway.
authors.forename: F
authors.initials: F
authors.lastname: Oppedal
authors.affiliation: Sustainable Aquaculture Laboratory - Temperate and Tropical, School of BioSciences, University of Melbourne, Melbourne, Vic., Australia.
authors.forename: T
authors.initials: T
authors.lastname: Dempster
mesh_terms: D000818:Animals; D033342:Copepoda / Q000502:physiology*; D004478:Ectoparasitic Infestations / Q000469:parasitology / Q000517:prevention & control / Q000662:veterinary*; D005393:Fish Diseases / Q000469:parasitology / Q000517:prevention & control*; D005618:Fresh Water / Q000032:analysis*; D020317:Salmo salar
keywords: Caligidae; Lepeophtheirus salmonis; Salmo salar; aquaculture; freshwater; parasite control