An evaluation of the genetic connectivity and temporal stability of the blue and red shrimp Aristeus antennatus: a case study of spawning females’ grounds in the Western Mediterranean Sea

The blue and red shrimp Aristeus antennatus has been intensively exploited by trawling fishery in the Western Mediterranean Sea. Implementation of an adequate management plan needs complete genetic data of the non-spawning and spawning grounds of the species. During the reproductive period, the species forms spawning aggregations in the middle slope, mainly constituted of mature females carrying spermatophores. Seven spawning females’ grounds in the Western Mediterranean Sea from Gulf of Lions (France) to Cabo de Palos (Spain) were sampled during two consecutive years, 2016 and 2017. This study assessed for the first time the levels of genetic diversity within spawning grounds, the genetic divergence among them and estimated the degree of temporal genetic stability using multilocus genotyping. Our results showed a high connectivity of the spawning females’ grounds that remains stable during the two analysed years, explained by passive larval dispersal, together with juveniles and adults’ migration. We advise that a future management plan for A. antennatus fishery should consider the Mediterranean Subarea GSA6 as a single unit, but it should be combined with local monitoring in order to ensure the sustainable exploitation of the populations.