1ST REPORT OF ALEXANDRIUM-MINUTUM HALIM IN A MEDITERRANEAN LAGOON

The occurrence of Alexandrinum minutum Halim (Dinophyceae) in a lagoon of Sicily (Italy) and its main morphological features are described. This small-sized dinoflagellate, which can produce Paralysing Shellfis h Poison (PSP), was found for the first time in April 1990 in inshore waters of Sicily - communicating with the Straits of Messina - where s mall-scale shellfish farming is practised. The highest cell concentrat ions were recorded in May 1991 (9 x 10(4) cells l-1) in the surface la yer, but no PSP human symptoms were reported. This month, A. minutum c ells were widely spread throughout the waters and 2% of the algal popu lation was constituted of chains of two cells.