Avaliação temporal da variabilidade genética da lagosta europeia (Palinurus elephas), no Mediterrâneo Ocidental da Espanha

Abstract

The European spiny lobster (Palinurus elephas) is a widely-distributed crustacean species with high commercial value and which presents a larval form phyllosoma with a long planktonic duration. Given that local fisheries have significantly declined in recent years due to overexploitation, there is an increasing necessity to develop conservation plans for this species. In order to evaluate the genetic variability, a population of Palinurus elephas was analyzed during 2006-2009, using 11 microsatellite markers. A total of 163 samples of P. elephas were collected over a period of four years (2006-2009) in Cullera, a small town located in the western Mediterranean. Samples were structured within each year to include both the summer (VR06, VR07, VR08) and winter (IV06, IV07, IV08, IV09) seasons. Furthermore, the genetic distance between the Cullera samples and another 10 P. elephas populations analyzed in a previous study (Western Scotland, Western Ireland, Brittany, Bay of Biscay, South Portugal, Western Mediterranean, North Western Mediterranean, Tunisia, Sicily and Greece) was estimated. The analyses revealed that the observed heterozygosity were consistently smaller than the expected heterozygosity values over the whole 4-year period. The polymorphism information content (PIC) values observed in most markers was moderate to high (0.30 to 0.89) and allowed for estimating diversity parameters and genetic differentiation. Lower Fst values were found between the seven samples of juvenile from Cullera and the Mediterranean populations, with the exception of Sicily, and larger differentiation estimates were obtained when comparing them with the populations located in the Atlantic (Scotland, Ireland, Brittany, Biscay and Portugal). The results do not indicate a significant reduction on the genetic diversity of this population, but showed that the influence of oceanographic barriers in the dispersal of species maybe contributing to the genetic difference between populations of P. elephas.