From seawater samples collected between 1984 and 1989 in 12 French coastal areas, a morphometric study have been realised on Dinophysis genera restricted to "acuminata" like species. Simple morphological criterias are given as suitable for discrimination of four dominant species occurring during toxic episodes in shellfish farms (Diarrheic Shellfish Poisoning): Dinophysis c-closed-integral. sacculus, D. c-closed-integral. acuminata, Dinophysis sp. and D. c-closed-integral. norvegica. This last species cannot be included in the "acuminata complex" and produces temporary blooms along southern Brittany coasts. Pending a more precise diagnosis it is recommended to clarify the relationship between toxin composition and each species previously described. |