Allozyme differentiation - a reply to Vainola

Abstract

In a series of papers we presented morphological, genetic and physiological results of blue mussels Mytilus edulis , reciprocally transplanted between one Baltic (6 to 7 ppt S) and one North Sea (Swedish west coast, 20 to 30 ppt S) site. The genetic paper also included allele frequency distributions from several other populations along the Swedish west coast. Our results indicated that differences in many of the morphological and physiological characters distinguishing Baltic and North Sea populations were due to phenotypic plasticity, although some characters were affected by a more direct genetic component. In a critical comment on our genetic paper Vaeinoelae (1990) argues for an alternative interpretation. He concludes that the observed allele frequencies following the mortality events are most likely due to contamination by local recruits and not to selective mortality within the transplanted populations. Although this may seem a probable interpretation we will argue that although we cannot reject the possibility of contamination in the transplants from the Baltic to the North Sea we can do so in North Sea to Baltic experiment.