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

Abstract

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.

Genetic Demography of the Blue and Red Shrimp, Aristeus antennatus: A Female-Based Case Study Integrating Multilocus Genotyping and Morphometric Data

“…More than 40% of males in summer groups originated from outside the Palamós ground [20], whereas the percentage of contribution from neighboring grounds to summer small females rose to 35% (present study) (Figure 6). Our results corroborate the connectivity between nearby fishing grounds of A. antennatus in the north-western Mediterranean Sea, which likely occurs through the dispersal of different stages of the life-cycle of A. antennatus, i.e., larvae, juveniles, and adults of both sexes [16,17,20,40].…”

“…On the other hand, Cannas et al [ 13 ] hypothesized that A. antennatus females could disperse more easily than males due to its main presence in intermediate currents that flow faster than deep currents. Recently, Agulló et al [ 17 ] reported the existence of horizontal displacements of A. antennatus females and a high genetic connectivity between spawning females’ grounds within the Mediterranean Subarea GSA6.…”

“…Larval dispersal by marine currents during the A. antennatus pelagic stage has been pointed out as the main responsible for the high level of genetic connectivity found across the Mediterranean Sea [ 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 ]. However, Guijarro et al [ 18 ] reported a possible migration of juveniles and adults, and Agulló et al [ 16 , 17 ] suggested adult migration as a contributor to the high genetic homogeneity found in the western Mediterranean populations.…”

“…Larval dispersal by marine currents during the A. antennatus pelagic stage has been pointed out as the main responsible for the high level of genetic connectivity found across the Mediterranean Sea [ 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 ]. However, Guijarro et al [ 18 ] reported a possible migration of juveniles and adults, and Agulló et al [ 16 , 17 ] suggested adult migration as a contributor to the high genetic homogeneity found in the western Mediterranean populations. Genetic relatedness analyses showed that spermatophores attached to females collected at 400–700 m depth during the reproductive period came only partially from males captured simultaneously with the females, whereas a large proportion of spermatophores belonged to unsampled and less related males, likely from other spawning grounds [ 19 ].…”