Seasonal polymorphism of the Black Seas dinoflagellates from genus Ceratium: C. furca, C. fusus, C. tripos (Dinophyceae)

Abstract

Anton M. Lyakh, Yulia V. Bryantseva

The seasonal polymorphism of the three species from genus Ceratium were described in the paper. The seasonal forms were distinguished by the sizes, biovolumes and surface areas of cells theca, and values of morphometric indexes. The breadth, biovolumes and surface areas of all species were higher in cold period. The length of the horns of C. fusus and C. tripos was 1.3-1.5 times higher in winter while the length of the horns of C. furca was 1.5 times higher in summer. The winter and summer periods were distinguished by the sea surface temperature: in winter the temperate was lower 12°, and in summer it was higher 20°. It is confirmed that species of the genus Ceratiumi has “summer” and “winter” forms which are the adaptations to seasonal changes of hydrological conditions.