GENETIC AND MORPHOLOGICAL VARIABILITY IN ROACH RUTILUS-RUTILUS, FROM AUSTRIA

Seven samples of roach (Rutilus rutilus L.) from the Austrian section of the Danube river, the Drau river and lake Wallersee were examined t o study possible population genetic effects of anthropogenic habitat m odification and subdivision. Genetic variability was assessed using el ectrophoretic variation of 11 enzyme systems coded by 14 gene loci. Ge netic variation of roach was remarkably high, and was mainly located w ithin samples while differences between them were weak. Morphometric a nalyses of conventional external measurements revealed considerable mo rphological variation within samples. Significant differences between samples mainly involved body depth and fin size, but did not allow ada ptive ecomorphological interpretations in several cases. The compariso n of morphological and genetic variation showed no significant correla tions but was limited by the narrow range of heterozygosity estimates.