Biosystematics and genetic relationships of Solea aegyptiaca and S. senegalensis

The isoenzymes from seven populations of Solea senegalensis or aegyptiaca were compared et 24-30 loci, six of which display significant differences in their allelic frequencies. In addition, these populations were compared to six other Soleidae species, namely Solea vulgaris, S. impar, S. lascaris, S. lutea, Michrochirus azevia, and M. variegatus. It was shown that S. senegalensis and S. aegyptiaca can be separated into two distinct genetic groups. Their high genetic similarity in comparison with the other species of Soleidae studied suggests that they have a common origin. The systematic status (species or semispecies) of these taxa could not, however, be elucidated. The high degree of genetic polymorphism observed in the regions where the two taxe are found together suggests that there still is some gene flow between them. However, this could be due to selection.