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Vol. 20 (2017 year), No. 2, DOI: 10.21443/1560-9278-2017-20-2

Makarevich P. R., Oleinik A. A.
Microplankton of the Barents Sea: current composition and structure on the eve of the winter

The results of microplankton (Protista) investigations in the Barents Sea (standard "Kola Meridian Transect", ~70–78° N, 33° 30' E) in November / December have been presented. Samples for the determination of the taxonomical composition and abundance have been fixed with buffered formalin and examined with light microscopy using Nageotte counting chambers. A list of species recorded in the Barents Sea on transect, abundance and vertical distribution of microplankton has been given: a) the seasonal composition of species (Ceratium fusus, Dicroerisma psilonereiella, Dinophysis rotundata, Lessardia elongata aff., Oxytoxum caudatum, Pronoctiluca pelagica, Protoperidinium brevipes, Prorocentrum balticum (Dinophyta), Corethron criophilum (Bacillariophyta), Coccolithus pelagicus (Haptophyta), Halosphaera viridis (Prasinophyta)); b) mean values of the total biomass of microplankton and its distribution in the water column (1.14 mkg/l in the layer of 50–0 m, 0.97 mkg/l – 100–50 m, 0.75 mkg/l – 200–100 m, 0.53 mkg/l – 300–200 m). Such parameter as dominant species in the structure of the total number is less constant (the ordinary dominant O. caudatum, subdominants – L. elongata aff., P. balticum, C. pelagicus, C. criophilum); in some years, at selected sites of the Barents Sea most of the total number has been formed to unusual species (Emiliania huxleyi, Mesoporos perforatus). The less stable characteristics of microplancton are dominant species composition in the biomass structure, total number of cells and their distribution in the water column.

(in English, стр.9, fig. 4, tables. 4, ref 20, Adobe PDF, Adobe PDF 0 Kb)

Vol. 28 (2025 year), No. 1, DOI: 10.21443/1560-9278-2025-28-1

Oleinik A. A.
Hexacrista intorta (Ciliophora, Tintinnida), a new genus and species from the waters of the North European basin

In the waters of the Greenland and Barents Seas, ciliates-tintinnids have been found, their lorica combining the definitive features of several genera of the Tintinnidae family, has an unusual, unique among all Tintinnida, exterior feature, i. e. spiral folding (corrugation) of the wall. The described tintinnids in terms of shell morphology correspond to the features of the Tintinnidae family Claparède & Lachmann, 1858, sensu Bachy et al., 2012 and combine individual features of its different genera: Salpingella, Amphorellopsis, Amphorides, Steenstrupiella. Based on the set of features that are taxonomically significant in the Tintinnidae family, the studied specimens do not have any closely related forms at the genus level. The results of the research allow us to establish a new genus with a new species in its composition for Tintinnidae (Ciliophora, Tintinnida) and to present a description of a new genus of ciliates-tintinnid Hexacrista gen. nov. with the species H. intorta sp. nov. from the waters of the North European basin of the Arctic Ocean.

(in Russian, стр.8, fig. 3, tables. 1, ref 8, AdobePDF, AdobePDF 0 Kb)