Présence d'un Protogonyaulax sp. sur le littoral atlantique français pendant l'hiver 1987

A dinoflagellate belonging to Protogonyaulax genera and forming more than 20 cells chains was observed from November 1987 to February 1988 in Vilaine Bay and in the west ofIle d'Yeu (France). This species was not detected in coastal phytoplankton during preceding surveys. Close to Protogonyaulax affinis it seems to be a winter developing species for this coastal area. Vertical distribution shows in december a migration of the patch towards deeper layers. Increasing occurrences of species belonging to Protogonyaulax (Alexandrium Balech) genera inshore or coastal waters need to pay more attention to the taxonomy of such organisms. Some species are effectively well known as poisons producers.