Variabilité génétique de Barbus meridionalis Risso (Cyprinidae) : une espèce quasi monomorphe

Abstract

Barbus meridionalis was sampled in five small rivers of middle altitude in three French mountains: the Pyrenees, the Massif Central and the Alps. The ecological preferendum of the species is discussed. The electrophoretic study of the allozyms of 34 loci shows an almost total lack of polymorphism. Few exceptions were observed in the Tech (Eastern Pyrenees) where three loci are polymorphic, and a stream of the Massif Central where a null allele is present at a high frequence. An hypothesis including a bottleneck by founder effect caused by the last glaciation is proposed.