Gene flow between populations of Balanus improvisus Darwin (Cirripedia) in British estuaries
E.R. Furman, A.B. Yule and D.J. Crisp

Samples of B. improvisus, a warm-temperate water barnacle, were collected from five British estuaries. The allele frequencies from ten enzyme loci were analysed using horizontal starch gel electrophoresis. The allele frequency distributions between samples differed significantly at only three out of eleven loci. Nei's genetic distances between populations were very low. The sample from the Conwy estuary showed a consistent deficiency of heterozygosity and large deviation from Hardy-Weinberg equilibrium. The population is considered to be rather isolated and to exhibit considerable inbreeding, mainly through self-fertilisation. Investigation of the salinity tolerance for adults, eggs and larvae shows that salinity would not be a barrier to migration from one estuary to another. The chances of the mass migration necessary to maintain the level of uniformity seen in B. improvisus allele frequencies must be very small indeed.

Keywords: gene flow, Cirripedia populations, Balanus improvisus.
Contents of this volume Sci. Mar. 53(2-3) : 465-472 Back PDF
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