Population genetic structure of wrasses used as cleanerfish in Atlantic salmon farming in Norway

The increasing use of wrasses as cleaner fish in the salmon farming industry has created local fishery in many regions in Norway. In several cases, live fish have been transported between regions without knowledge of the population structure of the three species in question (goldsinny, Ctenolabrus rupestris, rock cook, Crenolabrus exoletus, and corkwing, Symphodus melops ). Genetic studies based on variation in proteins were carried out, and polymorphic enzymes of potential use in popoulation studies were identified for all three species. For the most common wrasse the goldsinny, four loci (SDH-1*; PGM- 1*; GPI-1* and GPI-2*) were used to study genetic variation between geographic regions. Five samples collected in the southern part of Norway were compared and significant variation in allele frequencies were detected for SDH-1* and PGM-1*. The variation seemed to be associated with specific fjord - coastal area distribution