Parasites and Maturation Rate as Indicators of Population Structure in the Beaked Redfish Sebastes mentella (Sebastidae)

Abstract

The direction of phylogenesis of beaked redfish Sebastes mentella is considered based on a comparative analysis of the parasite fauna and maturation rate of individuals in the pelagic and near-bottom groups in the North Atlantic and the Norwegian-Barents sea populations. The individuals of the beaked redfish inhabiting the pelagic and bathyal zones of the Norwegian Sea’s northern part are characterized by a significantly higher similarity of the parasite fauna and lesser differences in the length and maturation age than that living in the pelagic and bathyal zones of the North Atlantic seas. This may indicate that the pelagic group of beaked redfish in the Norwegian Sea is at an earlier stage of formation than the pelagic group in the Irminger and Labrador seas, and the Norwegian-Barents sea population is phylogenetically younger than the North Atlantic one. The occurrence of mass migration of beaked redfish individuals from the pelagic zone of the Irminger Sea to the Norwegian Sea indicates a probable source of origin of its Norwegian-Barents sea population.