Heterotrophic flagellates in the littoral and sublittoral zones of the southeast part of the Pechora Sea

Abstract

For the first time, data on the heterotrophic flagellate fauna in the littoral and the sublittoral zones of the southeastern part of the Pechora Sea were obtained. Sixty-six heterotrophic flagellate species were found in the study region: 48 and 42 species were found on the shelf and in the intertidal zone, respectively. The most common species were Cafeteria roenbergensis, Paraphysomonas sp., Ancyromonas sigmoides, Cafeteria minuta, Actinomonas mirabilis, and Spumella sp. The littoral fauna of the heterotrophic flagellates was more peculiar than the sublittoral fauna and equally rich. In the region studied, the community can be divided into two types: (a) the predominantly littoral community characterized by a special composition of the dominant species and by high similarity between its local varieties and (b) the heterogeneous predominantly sublittoral community characterized by a lack of a complex of particular species. The local diversity of the heterotrophic flagellate community was low (on the average, 4.5 species per one sample 1 cm3 in volume). The overall distribution pattern of the flagellates was extremely heterogeneous. The large amount of species that were encountered only once causes a great variability in the species structure from one station to another. The total number of the species monotonously increased with the growth in the number of samples and no manifested saturation of the cumulative curve was reached. This indicates the potentially greater diversity of the heterotrophic flagellate species in the region studied.