A preliminary survey of Ostreopsidaceae (Dinophyta) in the Mediterranean: Molecular and morphological analyses of different isolates

Harmful algal blooms including outbreaks of epiphytic dinoflagellates, such as Ostreopsidaceae (Ostreopsis and Coolia spp), have affected various areas of the Mediterranean. Similar spring-summer blooms also interest Ionian and Tyrrhenian regions of Italy and the Catalan coast of Spain. In order to study the genetic variability of different geographical populations and clarify controversial taxonomical issues, molecular analyses are here coupled with the microscopical examination of the specimens. Distinct populations were isolated both from costal waters and seaweeds from Italy and Spain. Clonal cultures of Coolia and Ostreopsis spp. established from both countries were used for the 5.8S rDNA gene and ITS region sequence analysis. Sequence data indicate a high genetic similarity of Ostreopsis strains from different Mediterranean areas, despite evident morphometrical differences, as well as their divergence from tropical clones, as suggested by comparisons through the BLAST search database in GenBank. Possible relationships of the studied strains by their common geographycal origin vs. morphological criteria are important issues to be further investigated, together with a critical review of existing data from literature (literal)