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Volume 51, Nº 6 (2025)
- Ano: 2025
- ##issue.datePublished##: 15.11.2025
- Artigos: 7
- URL: https://bakhtiniada.ru/0134-3475/issue/view/24763
ОБЗОР
The Effect of Heavy Metals on Dinoflagellates
Resumo
Among the diverse marine phytoplankton, dinoflagellates are of great interest as a group of protists that dominates ocean ecosystems and causes harmful algal blooms (HABs). Information on the impact of pollutants (cadmium, nickel, copper, mercury, lead, zinc, etc.) on the population dynamics, morphology, biochemical parameters, and photosynthetic activity of this group of microalgae is summarized. The resistance of dinoflagellates to heavy metals (HMs) is considered along with the mechanisms of the impact of these substances on microalgae, in particular accumulation and toxicity, oxidative stress, inhibition of enzymatic activity, suppression of photosynthetic processes, and changes in cell morphology. The effects of HMs on ecosystem processes, including the exacerbation of HABs caused by dinoflagellates producing dangerous toxins, are discussed.
301-318
ОРИГИНАЛЬНЫЕ СТАТЬИ
Microfossil Taphocoenoses in Surface Sediments of East Siberian Sea and Podvodnikov Basin (Arctic Ocean) and Their Significance for Paleoreconstructions
Resumo
319-343
The First Barcoding Analysis of Symbiotic Nemerteans of the Genus Malacobdella Blainville, 1827 (Hoplonemertea, Monostilifera) from the Far Eastern Seas of Russia
Resumo
The occurrence of Malacobdella grossa in Peter the Great Bay, Sea of Japan, has been confirmed by an analysis of cytochrome c oxidase subunit 1 (COI) gene fragments. The sequences of four specimens from the Sea of Japan belong to the same haplotype and differ from the sequences of the specimens from the White and North Seas by 3–5 substitutions. This is the first hoplonemertean species whose trans-Arctic distribution range has been confirmed at the genetic level. The studied Malacobdella japonica specimens from Aniva Bay (Sakhalin Island) belong to the same haplotype as the specimens from Akkeshi Bay and Ibaraki Prefecture, Japan.
344-350
Survival Strategy of the Diatom Pseudo-nitzschia pungens (Grunow ex Cleve) Hasle, 1993 under Long-term Dark Conditions
Resumo
The physiological response of the marine diatom Pseudo-nitzschia pungens to dark exposure for 45 and 90 days and subsequent acclimation under re-illumination was studied. We have shown that the alga remains metabolically active between 0 and 45 days of dark exposure. This stage is characterized by the stabilization of cell culture density, activation of respiratory metabolism and synthetic processes, and a low rate of intracellular carbon (C) and nitrogen (N) consumption. Between 45 and 90 days of dark exposure, P. pungens cells enter a rest state accompanied by the cessation of cell division, suppression of synthetic processes, preservation of the light-harvesting complex, and almost complete suppression of photosynthesis. The viability of cells is provided by maintaining high respiratory activity and elevated level of intracellular C reserves. We have also shown that the step-by-step reorganization of the structure and function of the photosynthetic apparatus in P. pungens under long-term dark conditions contributes to the maintenance of cell’s photosynthetic competence and the subsequent recovery of the density of P. pungens population when re-exposed to light. The duration of the algae population recovery period, as well as the regeneration of the structure of their light-harvesting complex, is determined by the duration of exposure to darkness.
351-364
Determination of the Minimal Number of Microsatellite Loci for the Prior Assessment of Population Genetic Structure of the Japanese Sea Cucumber, Apostichopus japonicus (Selenka, 1867) (Echinodermata: Holothuroidea)
Resumo
365-374
Trophic Characteristics of Bivalve Mollusks (Bivalvia) from the Shallow Shelf of the Laptev Sea
Resumo
375-390
Авторский указатель за 2025 г.
Index of authors. V. 51, 2025
391-396