Analysis of meristic and mitochondrial DNA variation in Syngnathus abaster Teleostea Syngnathidae from two western Mediterranean lagoons
Hajer Ben Alaya; Daria Sanna; Marco Casu; Francesca Biagi; Paolo Francalacci; Marcella Carcupino; René Galzin; Jean-Pierre Quignard; Monia Trabelsi
Biologia (Bratislava) 66(6): 1140-1147
2011
ISSN/ISBN: 0006-3088
DOI: 10.2478/s11756-011-0127-x
Accession: 036245291
Syngnathus abaster is a euryhaline pipefish distributed in the Mediterranean, Black Sea, and the north-eastern Atlantic. Although its populations are characterised by high morphological plasticity, neither congruent information about the morphological differentiation of S. abaster populations from the Mediterranean lagoons is available, nor population genetic surveys have been so far performed. In this context, the aims of our study were as follow: i) to describe the variation at nine meristic characters of S. abaster from two western Mediterranean brackish-water areas: the Tunis north lagoon (Tunisia) and the Mauguio lagoon (France); ii) to analyse sequences of four mitochondrial DNA regions in order to evaluate the occurrence of genetic variation between the two areas, if any. The morphological survey revealed a subdivision into two distinct groups: the first included the Tunisian specimens, the second the French ones. Genetic analysis evidenced the occurrence of a sharp genetic structuring with high levels of genetic differentiation between Tunisian and French S. abaster populations. suggest that the evolutionary forces driven by the different biogeographical and ecological conditions of the two Mediterranean brackish-water areas have boosted the morphological and genetic divergence of the populations here analysed. The scarce potential of long-distance dispersal of S. abaster may have also enhanced the divergence retrieved.