Genetic polymorphism and differentiation among chub Leuciscus cephalus L. (Pisces, Cyprinidae) populations of Greece

To clarify the genetic structure of chub (Leuciscus cephalus L.) populations, eleven enzymatic systems corresponding to 20 putative loci were investigated in 15 populations from different rivers throughout Greece and one sample from France. The proportion of polymorphic loci detected ranged from 5 to 45% and the degree of expected heterozygosity from 0.019 to 0.072. Phenograms constructed from the allozyme data were generally concordant with the recognition of four subspecies of L. cephalus. Values of genetic distance among the populations, however, do not justify this classification. The possible influence of paleogeographic events on the phylogenetic relationships of the putative subspecies is discussed.