Sea lice (Lepeophtheirus salmonis) and anchor worms (Lernaea cyprinacea) found on sea trout (Salmo trutta) in the River Minho catchment, an important area for conservation in NW Spain

Abstract

The International Stretch of the River Minho (ISRM), in NW Spain, is an important area for marine and freshwater conservation. It constitutes the southern limit of distribution of migratory sea trout (Salmo trutta) and Atlantic salmon (Salmo salar), where their populations are considered as vulnerable and endangered, respectively. A sample of sea trout from the River Minho catchment (NW Spain) was examined for ectoparasites. Sea lice (Lepeoptheirus salmonis) were found on 10/113 fish (9%). Infection levels ranged from 0–8 lice/fish. Anchor worms (Lernaea cyprinacea) were also found, on three fish (3%). Lice identifications were confirmed by taxonomic and molecular analysis. This is the first time the presence of L. salmonis has been confirmed in NW Iberia. The confirmed presence of these parasites will inform conservation agencies, wild fisheries and sustainable aquaculture initiatives in this important area.