Centropages typicus and adhered vibrios in a neritic area of the Gulf of Genova.

Centropages typicus (Copepoda: Calanoida) is a common and abundant species of the neritic mesozooplankton of the Ligurian Sea, where occurs with density peaks which indicate the succession of different generations during the year. The population dynamics of C. typicus in the Mediterranean Sea seem to be regulated by the fluctuations of local environmental conditions and by the quality and the abundance of available food. Some bacteria, such as Vibrio spp., are found in association with the chitin of copepod exoskeleton; thus copepods can contribute to the spreading of human pathogens in marine waters. In this paper the data concerning some physico-chemical parameters (T, S, O2), chlorophyll a and mesozooplankton abundance collected between late spring and early autumn in two coastal stations of the Western Ligurian Sea in front of Alassio and Vado Ligure, are reported. In particular, the population structure of C. typicus and its association with adhered vibrios were considered. A remarkable abundance of adult (with percentages up to 49%) and copepodid C. typicus and a significant correlation between the occurence of C. typicus-adhered bacteria and water temperature with a peak of vibrios in July were found.