Relative Reproductive success of males in polyandrous crosses of Barbus meridionalis (Cyprinidae) revealed by microsatellite genotyping

Using microsatellite genotyping in Barbus meridionalis, we tried to assess the identity of fathers of progeny produced during four experimental polyandrous crosses involving the same four males and one or two females. The pooled analysis revealed that males had significantly different reproductive successes. We found no conspicuous causes explaining differential reproductive success in the behavioural data or in the physical characteristics of the males but a genetic determinism is the most parsimonious hypothesis to account for this variability. We argue that this conclusion is compatible with the hypothesis that the reproductive strategy of barbels, which involves large aggregations of males, is a result of sexual selection. This study provides guidelines for future interspecific crosses and constitutes the preliminary experiment of an investigation of the origin of a hybrid zone between Barbus barbus and Barbus meridionalis.