BIOCHEMICAL-GENETIC STUDY OF EUROPEAN WHITEFISH (COREGONUS-LAVARETUS)IN LAKE MONDSEE, UPPER AUSTRIA

Mature coregonids of Lake Mondsee were caught during spawning time on three known spawning sites. The aim of the study was to reveal whether the three stocks are reproductively isolated, and in consequence to d ecide whether they should be managed as separate stocks or as one panm ictic population. Fish were examined morphologically and their tissue samples were examined electrophoretically for the enzyme products of 3 7 genetic loci. The gill-raker numbers (28-40) and electrophoretic all eles were typical for European whitefish, Coregonus lavaretus. No gene tic differentiation (Nei's genetic distance D = 0.000) was found betwe en the three samples studied. The genetic characteristics of the Lake Mondsee whitefish population, based on pooled genetic data, was compar ed to several other European whitefish populations. The average hetero zygosity (6.5%) was high as usually in whitefish; genetic distances be tween the Lake Mondsee and three other European whitefish populations were within the range reported for the geographically distant populati ons of the species. Management implications of the results are briefly discussed.