Electrophoretic heterogeneity in Hediste diversicolor (Annelida : Polychaeta) within and between estuaries in Northern France

We compared the general protein and non-specific esterases band patterns of different populations of the polychaete annelid Hediste diversicolor (O.F. Muller) (Nereididae) located at different spatial scales in the estuaries of Aa, Canche, Authie and Rance (France). Our results indicate a restricted gene flow between populations located in different estuaries but also with in the same estuaries. These results could be explained by the particular l ife cycle of this species ("bentho-pelagic" life cycle with a brief semi-pe lagic larval phase) which does not favour a great dispersion of larvae and by local marine currents and eroding channels which canalize an oriented di ssemination of larvae. In a preliminary step, intra-population banding patt ern variability was assessed in two populations by high resolution two-dime nsional electrophoresis analysis of proteins. Our results show a great inte r-individual variability in protein profiles. These results are in good con cordance with the hypothesis of the existence of a restricted gene flow bet ween populations.