Genetic methods reveal high diversity and no evidence of stock structure among cuckoo rays (Leucoraja naevus) in the northern part of Northeast Atlantic

Abstract

The high level of exploitation and slow population growth rates of many elasmobranch species are causing worldwide concern about their status. Genetic methods offer the potential to gather information on the stock structure and conservation status of species with implications in the delineation of appropriate management units. However, despite several calls from the scientific community, they are still largely ignored in fisheries management. Here, we use genetic approaches to assess the population structure of the cuckoo ray (Leucoraja naevus), a species of skate that was recently designated as vulnerable in Irish waters by the International Union for Conservation of Nature. By genotyping individuals (n = 188) originating from a vast geographic area with nine microsatellite markers, we do not find evidence of population structuring but cuckoo rays in Irish waters seem to belong to a single genetically diverse panmictic population despite the restricted movements observed in closely related species. Cuckoo rays should therefore continue to be monitored as a single stock in this area.