Multivariate analysis of genetic exchanges between Solea aegyptiaca and Solea senegalensis (Teleosts, Soleidae)

Electrophoretic data from different populations of the teleosts Solea senegalensis, S. aegyptiaca and S. vulgaris were analysed using multivariate analysis. This confirmed that Solea vulgaris is very different genetically and isolated from both senegalensis and aegyptiaca , and that the latter two forms are also well differentiated. The presence of senegalensis alleles in the aegyptiaca population of the Golfe-du-Lion, and reciprocally, aegyptiaca alleles in the senegalensis population of the Gulf of Tunis, suggests that genetic exchange occurs between them. The association of these alleles (gametic disequilibria) and the existence of hybrid individuals show that these exchanges are an actual process rather than a consequence of 'fossil' gene flow. Furthermore, the genetic introgression seems to be asymmetrical in the two regions studied where they come into contact.