DISTRIBUTION AND NUMERICAL TAXONOMY OF VIBRIONACEAE IN THE WATERS OF THE STRAITS-OF-MESSINA

The results of a study carried out by numerical analysis on Vibrio str ains isolated from the waters of the Straits of Messina are reported. The quantitative data showed the presence of low bacterial densities ( ranging from 9 to 99 CFU/100 mi of water) due to the intense currents which characterize this area; also the highest bacterial counts were g enerally found during the ''montante'' current. With regard to the qua litative results, there was a predominance of vibrios belonging to V. mediterranei, V. splendidus II and V. pelagius II species, which repre sented respectively 25%, 19% and 13% of the total bacterial population . The species distribution did not seem related to sampling stations o r depth. The taxonomic structure, obtained using the simple matching c oefficient and unweighted average linkage clustering, revealed the pre sence of 7 main clusters (S = 80-95%), which included strains of vario us origin because of the particular turbulence of the waters of the St raits.