We carried out a spatial and temporal genetic differentiation analysis using seven populations of the marine crab Liocarcinus depurator to elucidate the effect of three oceanographic discontinuities in the Atlanto-Mediterranean coast: Gibraltar Strait, Almeria-Oran Front and Ibiza Channel. To conduct this study, a 527 bp fragment of the mitochondrial COI gene was sequenced in individuals captured in the period 2014-2018 from the following Iberian coast populations: Cádiz, West Alboran, East Alboran, Alacant, Valencia, Ebro Delta and North Catalonia. Two haplogroups were detected; one characteristic of Atlantic waters and the other of Mediterranean, and their distribution allowed understanding the connectivity between populations. The effect of the oceanographic fronts on gene flow varied over time. Their effects were significant for the Gibraltar Strait (2014 and 2017), Almeria Oran Front (2013, 2014, 2015, 2016 and 2017) and Ibiza Channel (2015). Interestingly, the joint analysis of West Alboran, East Alboran and Alacant populations allowed detecting in a more precise scale the spatial location of the Almeria Oran Front. Finally, significant differences were observed in connectivity between Valencia and Ebro Delta in 2015, although there is not an oceanographic discontinuity between them. The main conclusion is that thegene flow is mediated by oceanographic fronts, but their intensity and effects change over time

Ministerio de Economía y Competitividad, Spain (CTM2017-88080 AEI/FEDER, UE) (CTM2015-66400-C3-3-R MINECO/FEDER) and the Generalitat de Catalunya, Spain (2017 SGR 1120)

VII International Symposium on Marine Sciences (ISMS 2020), 1-3 July 2020 (Barcelona).-- 1 page

Peer reviewed