Anàlisi genètic de les barreres oceanogràfiques a l'Atlàntic i el Mediterrani amb Liocarcinus depurator al llarg del temps

Abstract

Oceanographic discontinuities are very important for the study of genetic connectivity between populations. Different processes may affect the dispersion of marine organisms, which is necessary to understand their genetic distribution. In this research we use mitochondrial gen COI in order to determine the distribution patterns for Liocarcinus depurator and thereby study the effect of three fronts from the Atlantic Ocean and the Mediterranean Sea (Gibraltar Strait, Almeria-Oran Front and Ibiza Chanel) across time. A total of 147 individuals were sampled from five different localities: Cadis, Malaga, Alacant, Valencia and Delta the same year (2013) to have good information of genetic variability and current patterns. Afterwards, we did a temporal study comparing our results with previous analyses of the same specie and localities but in different years (2005-2007 and 2009-2010). Isolation by distance was found with the individuals obtained in 2013, seeing two different groups: the Atlantic (with individuals from Cadis and Malaga) and the Mediterranean (mostly individuals from Alacant, Valencia and Delta). The temporal study reveals us variability in Cadis and Alacant over time. Ours results indicate that genetic flux is strongly attached to current patterns across oceanographic discontinuities, mainly unidirectionals, although they vary because of different factors which we still do not know, we can just guess from the genetic data. To sum up, our research tell us that populations are not stable along time and show the importance of time and space investigation with marine organisms