Genetic diversity, growth, maturity and migration, in catfish (Anarhichas lupus L.) / Genetic diversity, growth, maturity and migration, of the Atlantic wolffish (Anarhichas lupus L.)
In this study, the genotype, sexual maturity and growth of catfish from the Westfjords and Eastfjords were investigated. The genotype study used 16 genetic markers and the Rhodopsin gene. Despite the fact that catfish is a local fish and there is little drift on its eggs and larvae, no differences in its genotype were found between regions or years with the genetic markers that were studied. The genetic studies showed a reduction in the population size of catfish in Iceland. In the warm seas out of the Westfjords, catfish grow faster and reach sexual maturity younger and smaller than catfish in the colder seas out of the Eastfjords. The results were examined on the basis of catfish biology, the length of time that catfish has been distinguished between areas around Iceland and the value of the study for sustainable fishing.
The stock structure of the Atlantic wolffish was investigated at Icelandic fishing grounds from two areas with different temperature regimes, using 16 microsatellite loci and the Rhodopsin gene. Growth and maturity was also examined. Despite the potential of the Atlantic wolffish to exhibit genetic structure (lack of eggs / larval dispersal and adults are sedentary), the genetic tests applied in this study did not detect significant genetic differentiation among the samples analyzed. However, the results on genetic diversity revealed a significant decrease in population size (bottleneck effect). Atlantic wolffish grows faster and matures at a younger age and smaller size in the warmer sea west of Iceland than in the colder sea east of Iceland. These results are discussed in terms of biological characteristics of Atlantic wolffish, recent isolation of populations and their application to sustainable fisheries management issues.