GENETICS OF WHITEFISH AND VENDACE IN ENGLAND AND WALES

Proportion of loci polymorphic (P) and mean heterozygosity per locus ( H(exp)) were P = 0.130 and H(exp) = 0.096 for C. albula from the Engli sh Lake District and P = 0.217 and H(exp) = 0.046 for C.lavaretus from the English Lake District and Llyn Tegid, Wales in 1991-2. Significan t deviation from the Hardy-Weinberg model was observed at the superoxi de dismutase (sSOD) locus in C. albula from Bassenthawaite Lake. This could have been due to chance, to the Wahlund effect or to selection. Genetic distances between the two species were consistent with their taxonomy and genetic differentiation was much greater for the C. lavar etus populations than for the two geographically close C. albula stock s. Llyn Tegid C. lavaretus showed unique alleles at two loci and conse rvation of fish in this lake is therefore of great importance. Red Tar n C. lavaretus differed most from other Lake District populations prob ably due to founder effects from early stocking events and/or from sel ection due to the high altitude of this lake.