Search

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 Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature. This work was supported by a grant from Spanish Ministerio de Economia y Competitividad (CTM2014-54648-C2-2-R) to MIR. LP and MA benefited from predoctoral fellowship from the Universitat de Girona (BR2014 and IFUdG2018, respectively)

In this study, we quantified the three key biological processes, growth, recruitment, and dispersal pattern, which are necessary for a better understanding of the population dynamics of the blue and red shrimp

The population biology of the deep-sea shrimp Aristeus antennatus, as with other exploited demersal species, is usually studied using data from fishery statistics. Such statistical analyses have shown female-biased sex ratios during the spawning season in this species. Because the abundance of males increases at greater depths that are not exploited by fisheries (virgin grounds), knowledge on their recruitment is limited. Here, the growth and recruitment of A. antennatus males at fishing grounds was evaluated. This was achieved by integrating information on previously identified breeding behaviours and by tracing the young-of-year cohort through genotyping at 10 microsatellite loci. Using a codend and a codend cover with distinct meshed windows, four groups of males were collected in winter and in a subsequent spawning summer season. Summer collections were mostly composed of pre-adult males, reaching sizes that are to be expected from the growth of winter juveniles, however, many specimens also originated from nearby grounds. This result indicates the horizontal dispersal of male juveniles via intermediate and deep oceanographic currents. Such dispersal complements passive larval dispersal in surface waters, and contributes to the weak genetic divergence among regional fishing grounds. These features could be shared by other deep-sea crustacean and fish species, and should be considered for the sustainable exploitation of demersal fisheries.

Temporal variability of the genetic structure and connectivity patterns of the blue and red shrimp Aristeus antennatus in the seven most important fishing grounds of the Western Mediterranean Sea, were assessed using twelve microsatellite loci during 2 consecutive years (2016 and 2017), in a total of 1403 adult individuals. A high level of geographical connectivity among groups was observed in the two studied years. In fact, no significant geographical differentiation was found in 2016 (FST = 0.0018, p > 0.05), whereas it was indicated in 2017 (FST = 0.0025, p FCT = 0.0006, p A. antennatus.