The sea louse Caligus elongatus utilizes a range of marine fish species as hosts, and it has been suggested that fish farms are infected with adult @entity70251 from wild fish hosts. We assessed experimentally whether dislodged lice return to their original host species. Adult lice from wild lumpfish and @entity25512 were presented to lumpfish, @entity42549 , @entity7980 , @entity25512 and European plaice. All fish species became infected. Lumpfish and cod were strongly preferred, followed by @entity25512 , trout and plaice. Lice from wild @entity25512 showed a preference for @entity25512 and lumpfish, followed by cod, @entity42549 and plaice. The mtCO1 gene was used to determine the genotypes of the lice. Lice from lumpfish were genotype 1. Lice from @entity25512 were mainly genotype 2. The two genotypes of @entity70251 differed slightly in their host preferences: lice from @entity25512 were less discriminating. The data support the hypothesis that adult @entity70251 may transfer between different host species. Cod is an attractive host for lice from both lumpfish and @entity25512 , which suggests that @entity70251 may become a serious pest of farmed cod.

Host preference of adult Caligus elongatus Nordmann in the laboratory and its implications for XXXX aquaculture.

@entity25512 :: ('8060', 'Species') :: ['saithe'] @entity7980 :: ('8049', 'Species') :: ['Atlantic cod'] @entity70251 :: ('154813', 'Species') :: ['C. elongatus'] @entity42549 :: ('227976', 'Species') :: ['sea trout']
@entity7980 :: (8049,Species) :: ['Atlantic cod']
