Geographical variation ofBalanus improvisusin biochemical and morphometric characters

Abstract

Samples ofBalanus improvisuswere collected from 15 sites in the Baltic, the west coast of Sweden, the British Isles and North America. They were analysed with horizontal starch gel electrophoresis for 11 loci and with opercular plate morphometry for 10 metrical characters. Analyses of isozyme patterns revealed a high degree of genetic similarity amongst populations. The Baltic sites, however, showed less heterozygote deficiency than the British and American sites indicating higher stability and outcrossing in the Baltic. Morphometric characters showed somewhat more heterogeneity than isozymes. The Baltic was relatively more homogeneous by morphometrical characters than by isozymes compared with the other areas. Both analyses separated to some extent the three geographical regions from each other and clustered sites by salinity. Individuals at low salinity had relatively small opercular openings compared to individuals from high salinity.