Evolutive observations on discontinuous populations of Alcyonidium polyoum (Hassall, 1841) (Bryozoa, Ctenostomida) along the coasts of Galicia and the Bay of Biscay

Abstract

An electrophoretic study, using polyacrylamide gradient gels, was performed on various populations of Alcyonidium polyoum (Hassall, 1841) from Galicia and the Bay of Biscay. lndependently of the fragmentation of the distribution area of the species, the populations are situated along a cline. Genetic isolation is beginning to appear in the populations from Arcachon and Ré Island, both geographically isolated localities. The population of Ré could represent an example of genetic drift.