Some of the microalgal species discovered in the Gulf of Naples. a Skeletonema dohrnii Sarno & Kooistra, a species very similar to S. marinoi Sarno & Zingone, discovered instead in the Adriatic Sea. Both species bloom in late winter-early spring, whereas the most abundant species in the GoN, S. pseudocostatum, blooms in late spring b Bacteriastrum parallelum Sarno, Zingone & Marino, a solitary diatom species in a genus entirely consisting of colonial species c Azadinium dexteroporum Percopo & Zingone, a dinoflagellate producing several toxins of the group azaspiracids, and the first in this genus discovered in the Mediterranean Sea d Phaeocystis cordata Zingone & Chrétiennot-Dinet, a prymensiophyte that differs from all the congeneric species because it apparently lacks a colonial stage.