Genetics of Zoarces populations

• Published in: Hereditas Vol. 73; no. 2; pp. 233 - 238
• Main Authors: FRYDENBERG, OVE, GYLDENHOLM, A. O., HJORTH, J. P., SIMONSEN, VIBEKE
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.04.1973
• ISSN: 0018-0661; 1601-5223
• DOI: 10.1111/j.1601-5223.1973.tb01084.x

EstIII genotypes of 16,214 adult Zoarces viviparus have been scored in samples from 46 localities in the North Sea, the Kattegat, the Danish fjords, the Danish belts, and the Baltic Sea. All populations were polymorphic for the two alleles EstIII1 and EstIII2, but the gene frequency ofEstIII1 varied from 1–2 per cent in the eastern Baltic Sea to 44–47 per cent in the inner parts of Danish fjords opening into the Kattegat. Two major gene‐frequency clines were found. One starts in the Kattegat with a frequency of some 30 to 40 per cent, develops through decreasing frequencies in the belts, and reaches its minimum of 1–2 per cent in the Baltic Sea. Another cline is apparent in the North Sea where the frequency, being higher than 30 per cent at the two northernmost stations, decreases going southwards to reach a low 8 per cent on the Dutch coast. Microgeographical frequency trends, developed over distances of the order of 20 to 40 kilometres, were seen in two Kattegat fjords, in which the frequency was higher in the inner parts than at the mouth. Comparatively high frequencies were also found in other fjords, indicating a certain generality of these microgeographical clines. The bearing of these results on the problem of the maintenance of polymorphisms is briefly discussed.