Assessment of genetic diversity and population structure of the common littoral shrimp Palaemon serratus (Pennant, 1777) by microsatellites: Towards a sustainable management

Abstract

The common littoral shrimp Palaemon serratus is an ecologically and economically important decapod crustacean. Understanding the spatial structure of its populations is crucial to implement effective management strategies. In this study, 17 polymorphic microsatellite nuclear markers were examined in 252 individuals to explore the genetic diversity and the population structure underlying the geographical distribution of this crustacean in European waters. Basic genetic descriptors, population genetic analyses based on FST, analysis of the molecular variance (AMOVA), Bayesian clustering and the Mantel test were performed. Genetic differentiation was significant among sampling sites. AMOVAs and Bayesian assignment tests showed genetic differentiation among localities from the Atlantic coast and those belonging to the area of the Strait of Gibraltar and the Mediterranean Sea. The Guadalquivir estuary was significantly different from the remaining localities. A biogeographical break was detected to the west of the Strait of Gibraltar, and evidence of isolation by distance was obtained. Localities on both sides of the English Channel showed genetic differentiation with the rest of the Atlantic sampling sites, indicating a biogeographical break in this area. These results will contribute towards the better understanding of the biology and ecology of this shrimp and management of the valuable fishery. Two priority areas were delimited: the Atlantic and the Gibraltar–Mediterranean. The Guadalquivir estuary, Anglesey and Calais should also be considered as different genetic stocks.

Genetic diversity and population structure of the rockpool shrimp Palaemon elegans based on microsatellites: evidence for a cryptic species and differentiation across the Atlantic–Mediterranean transition

“…In this study, microsatellite markers were used for the analysis of the genetic diversity and population structure of the shrimp P. elegans. Levels of polymorphism were in line with those found in the counterpart common littoral shrimp P. serratus 25,29 . Sampling sites showed similar levels of genetic diversity (Na, A, AR Heterozygote deficit caused by subpopulation structure (Wahlund effect) could not be completely ruled out in localities where an arbitrary admixture of individuals from putative different species was found.…”

“…Notwithstanding, it is known that population connectivity across the Atlantic-Mediterranean transition is reduced in other species by different oceanographic discontinuities, namely the Strait of Gibraltar 24,44 , the Balearic Front and the Ibiza Channel 45,46 . Most recently, in the congeneric common littoral shrimp Palaemon serratus, both mtDNA 47 and nuclear 25 markers have reported strong genetic differentiation among Atlantic and Mediterranean localities with an unusual phylogeographical break located west of the Strait of Gibraltar in the Gulf of Cádiz.…”

“…Specifically in population genetics, microsatellites are extremely valuable tools as they might reveal the existence of genetically distinct populations even in fine-scale studies 20 . In fact, microsatellite loci have been crucial in understanding the population structure of several shrimp species as Penaeus vannamei 21 , Penaeus monodon 22 , Pandalus borealis 23 , Aristeus antennatus 24 or Palaemon serratus 25 . Thanks to the advent of high-throughput sequencing technologies, the development of microsatellite markers in non-model species has become a rapid and cost-effective process 26 .…”

Mitogenome phylogenetics in the genus Palaemon (Crustacea: Decapoda) sheds light on species crypticism in the rockpool shrimp P. elegans

“…Two geographic lineages were identified in P. serratus with an unusual phylogeographical break located west of the Strait of Gibraltar in the Gulf of Cádiz. In the light of those findings, these two lineages were attributed to be different populations of P. serratus, as no consistent morphological differences were found among them [88]. Here we presumed that Atlantic and Mediterranean lineages could be actually two allopatric species rather than populations of the same species.…”

“…Although the estimates involving the Mediterranean sample of P. serratus must be taken carefully, as only three PCG fragments could be recovered, previous population genetics analyses would support the consideration of these two populations as separated species. Strong genetic differentiation between Atlantic and Mediterranean localities was detected along the geographical distribution range of P. serratus using two mitochondrial and one nuclear PCG [87] and 17 microsatellite markers [88]. Two geographic lineages were identified in P. serratus with an unusual phylogeographical break located west of the Strait of Gibraltar in the Gulf of Cádiz.…”