Marine Biological Journal <p>Морской биологический журнал Marine Biological Journal.</p> <div><em><strong>Launched in February 2016.</strong></em></div> <div><em><strong>Certificates of registration:</strong></em></div> <div>print version: <a href="" target="_blank" rel="noopener">ПИ № ФС 77 - 76872 of 24.09.2019</a>.</div> <div> <div><em><strong>Founder:</strong></em></div> <div>A. O. Kovalevsky Institute of Biology of the Southern Seas of RAS.</div> </div> <div><em><strong>Publishers</strong></em>:</div> <div><a href="" target="_blank" rel="noopener">A. O. Kovalevsky Institute of Biology of the Southern Seas of RAS</a>,</div> <div><a href="" target="_blank" rel="noopener">Zoological Institute of RAS</a>.</div> <div>ISSN 2499-9768 print.</div> <div><em><strong>Languages: </strong></em>Russian, English.</div> <div><em><strong>Periodicity:</strong></em> four issues a year.</div> <div> </div> <div><strong>Authors do not need to pay an article-processing charge.</strong></div> <div>The payment of royalties is not provided.</div> <div> </div> <div>Author recieves one copy of printed version of the journal as well as .pdf file.</div> <div> </div> <div> <div class="siteorigin-widget-tinymce textwidget"> <p>Marine Biological Journal is an open access, peer reviewed (double-blind) journal. The journal publishes original articles as well as reviews and brief reports and notes focused on new data of theoretical and experimental research in the fields of marine biology, diversity of marine organisms and their populations and communities, patterns of distribution of animals and plants in the World Ocean, the results of a comprehensive studies of marine and oceanic ecosystems, anthropogenic impact on marine organisms and on the ecosystems.</p> <p>Intended audience: biologists, hydrobiologists, ecologists, radiobiologists, biophysicists, oceanologists, geographers, scientists of other related specialties, graduate students, and students of relevant scientific profiles.</p> <p>The subscription index in the “<a title="Russian Press MBJ" href="" target="_blank" rel="noopener">Russian Press</a>” catalogue is Е38872.</p> </div> </div> A. O. Kovalevsky Institute of Biology of the Southern Seas of RAS, Sevastopol, Russian Federation en-US Marine Biological Journal 2499-9768 On the 85th anniversary of the world-famous parasitologist – professor Albina Gaevskaya <p>On 21 August, 2022, professor Albina Gaevskaya celebrates her anniversary. She is an outstanding parasitologist who described 1 subfamily, 14 genera, and over 100 new marine parasite species and published more than 380 scientific papers, <em>inter alia</em> 30 monographs and 5 patents. Under her supervision, 13 PhD theses were defended.</p> V. M. Yurakhno Copyright (c) 2022 A. O. Kovalevsky Institute of Biology of the Southern Seas of RAS 2022-09-13 2022-09-13 7 3 107 110 On the anniversary of D. Sc. Alexander Prazukin <p>On 1 September, 2022, D. Sc. Alexander Prazukin celebrates his 70<sup>th</sup> birthday. A. Prazukin, the leading researcher of IBSS laboratory of extreme ecosystems, is the author of about 200 scientific papers, a member of editorial boards of several scientific journals, and a deputy chairman of the Crimean Branch of Russian Hydrobiological Society of the RAS.</p> Colleagues Copyright (c) 2022 A. O. Kovalevsky Institute of Biology of the Southern Seas of RAS 2022-09-13 2022-09-13 7 3 111 112 A few pages from the life of Vitaly Giragosov (anti-obituary) <p>On 20 February, 2022, our dear friend and colleague, Vitaly Giragosov, suddenly passed away. He was a well-known specialist in ichthyology and ornithology and the author of numerous scientific papers.</p> A. N. Khanaichenko Copyright (c) 2022 A. O. Kovalevsky Institute of Biology of the Southern Seas of RAS 2022-09-13 2022-09-13 7 3 113 114 Effect of hypoxia on immune system of bivalve molluscs <p>Over the past decades, research on bivalve immune system is focused on studying the effect of environmental factors on the basal status of defense systems. The immune system of bivalves is greatly affected by abiotic factors, and the most significant ones are water temperature, salinity, and level of dissolved oxygen. Hypoxia is widespread in the coastal waters of the World Ocean since the 1950s. Hypoxic zones (with dissolved oxygen concentration &lt; 0.5 mL O<sub>2</sub>·L<sup>−1</sup>) occur in shelf areas for a long time corresponding to the life cycle of many hydrobionts. Being benthic organisms, bivalve molluscs often experience reduced dissolved oxygen concentrations. This group of aquatic invertebrates both plays an important role in aquatic ecosystem functioning and is actively used in aquaculture. The efficiency of bivalve cultivation directly depends on its immune status determining resistance to diseases. The immune system of bivalve molluscs is based on a complex of nonspecific reactions of cellular and humoral components. Hemocytes circulating in the hemolymph are the key effectors of the cellular immune response which, along with the barrier tissues of molluscs, synthesize humoral factors with a wide spectrum of antimicrobial activity. The hemolymph of various bivalve species contains different cell types differing by size, morphology, and granulation of cytoplasm. Most bivalve species have 2 types of hemocytes – granular and agranular ones; those can be subdivided into morphotypes depending on number and color of granules, size of the nucleus, and presence of organelles in the cytoplasm. Granulocytes are considered the main immune cells that perform phagocytosis and (or) encapsulation of infectious agents, as well as their subsequent neutralization by releasing reactive oxygen species, lysing enzymes, and humoral antimicrobial proteins. Moreover, the complex of defense systems includes an antioxidant system which is closely related to mollusc immunity since it neutralizes reactive oxygen species releasing during cellular immune mechanism activation. An excess of these compounds damages mollusc cells by oxidizing proteins, cytoplasmic membrane lipids, and DNA. This article provides data on an oxygen deficiency effect on the cellular and humoral components of the immune system, as well as the tissue antioxidant complex of bivalve molluscs.</p> A. Y. Andreyeva E. S. Kladchenko O. L. Gostyukhina Copyright (c) 2022 A. O. Kovalevsky Institute of Biology of the Southern Seas of RAS 2022-09-13 2022-09-13 7 3 3 16 State of population of Calanus euxinus (Copepoda) in the open pelagial and on the shelf of the Black Sea near Crimea in autumn 2016 <p>A copepod <em>Calanus euxinus</em> Hulsemann, 1991 is one of the most abundant mesozooplankton species constituting up to 60–80 % of planktonic crustacean biomass in the deeper Black Sea and being the main food component for small pelagic fish. Data on abundance, biomass, age structure, and lipid reserves of <em>C. euxinus</em> are required to estimate the state of its population in the open pelagial and on the shelf of the Black Sea. The data were obtained during the 89<sup>th</sup> cruise of the RV “Professor Vodyanitsky” (30.09.2016–09.10.2016) in the northwestern, central, and northeastern sea (62 stations). Zooplankton was sampled with a Bogorov–Rass net (mouth area of 0.5 m²; mesh size of 300 μm) by vertical net hauls from the seabed to the surface on the shelf and from the lower border of the oxygen zone to the surface in the deep-sea area. The samples were fixed with 4 % formaldehyde; in the laboratory, the abundance and biomass of all copepodite stages of <em>C. euxinus</em> were determined. Wax ester content in the bodies of late copepodite stages and adult specimens was estimated based on the specific oil sac volume (% of the body volume). The relationship between the quantitative species distribution and the habitat depth and macroscale hydrological circulation was revealed. In the deep-sea area, the mean abundance and biomass of <em>C. euxinus</em> amounted to (8.3 ± 0.8) thousand ind.·m<sup>−2</sup> and (7.1 ± 0.7) g·m<sup>−2</sup>, respectively. On the outer shelf, the abundance and biomass of this species decreased twofold – down to (4.2 ± 1.4) thousand ind.·m<sup>−2</sup> and (3.3 ± 1.2) g·m<sup>−2</sup>, respectively. In the deep-sea area, copepodites V, females, and males constituted 91 % of the total abundance and 96 % of the total biomass of the population. On the outer shelf, the ratio of these developmental stages reduced to 67 % and 86 % of the total abundance and biomass, respectively. In the deeper pelagial, the specific oil sac volumes in copepodites V, females, and males [(17.1 ± 0.6), (11.2 ± 0.8), and (11.9 ± 0.5) %, respectively] were twice as high as in the same developmental stages from the outer shelf [(8.1 ± 0.8), (4.7 ± 0.8), and (6.0 ± 0.5) %, respectively] indicating a relation between lipid accumulation in this species and hypoxic conditions of the biotope. Relatively high values of the abundance, biomass, and wax ester content in <em>C. euxinus</em> indicate that the population returned to its previous state – the one observed <em>prior</em> to expansion of alien ctenophores in the late 1980s and recent climatic changes resulting in a warming of the Black Sea basin.</p> E. S. Hubareva B. E. Anninsky Copyright (c) 2022 A. O. Kovalevsky Institute of Biology of the Southern Seas of RAS 2022-09-13 2022-09-13 7 3 17 27 New reports of suctorian ciliates (Ciliophora, Suctorea) epibiont on halacarid mites and a harpacticoid copepod from Türkiye <p>Suctorian ciliates are common epibionts on marine and freshwater invertebrates. In the present study, three epibiont suctorian ciliate species, viz. <em>Praethecacineta halacari</em> Schulz, 1933, <em>Thecacineta calix</em> (Schroder, 1907), and <em>Thecacineta cothurnioides</em> Collin, 1909, are reported. Hence, <em>P. halacari</em> was observed on the ventral side of the idiosoma and legs of halacarid mite <em>Copidognathus brachystomus</em> Viets, 1940 and ventral side of <em>Copidognathus tabellio</em> (Trouessart, 1894). <em>T. calix</em> was reported on halacarid mite <em>Maracarus gracilipes</em> (Trouessart, 1889) – a new host species for the ciliate. <em>T. cothurnioides</em> was found on two different harpacticoid copepod specimens. The species <em>T. cothurnioides</em> is recorded from Turkish coast for the first time. <em>T. calix</em> is reported from Antalya for the first time. Finding of <em>P. halacari</em> is the first record for Izmir area. The data on distribution of all registered suctorian species are provided as well.</p> F. Durucan I. Dovgal Copyright (c) 2022 A. O. Kovalevsky Institute of Biology of the Southern Seas of RAS 2022-09-13 2022-09-13 7 3 28 33 History of dispersion of the North American polychaete Marenzelleria neglecta Sikorski & Bick, 2004 (Annelida: Spionidae) in the northeastern Sea of Azov <p>In the early 2010s, the alien polychaete worm <em>Marenzelleria neglecta</em> Sikorski &amp; Bick, 2004 invaded the Sea of Azov. In few years, the species has widely spread over the desalinated sea area. Moreover, it was recorded in the Don delta and in the Sea of Azov–Kuban estuaries. This alien species formed a stable and numerous colony localized in the northeastern Sea of Azov; the history of this formation is traced based on material of complex hydrobiological and hydrological surveys of 2010–2020. The colony of this species developed against the backdrop of an increase in water salinity. Obviously, this factor had a decisive effect on the invasive process. An outbreak of abundance observed in the western Taganrog Bay in 2012 and 2013 was followed by a sharp decrease in abundance – down to complete absence of this polychaete worm in the samples. A drop in abundance was accompanied by a reduction of its range and a shift in the core of abundance towards sea areas with the lowest salinity. To date, there is a stable <em>M. neglecta</em> population in the central and eastern Taganrog Bay. Changes in the structure of prevalence in benthic communities during invasion were analyzed. As shown, the ratio of alien polychaetes in the periods of their mass development reached 92 % of the total abundance of benthos at individual stations.</p> L. A. Zhivoglyadova N. S. Elfimova V. G. Karmanov Copyright (c) 2022 A. O. Kovalevsky Institute of Biology of the Southern Seas of RAS 2022-09-13 2022-09-13 7 3 34 43 Dynamics of free amino acids in the brown alga Fucus vesiculosus Linnaeus, 1753 from the Barents Sea throughout the year <p>Free amino acids (FAA) are a significant biochemical component of any cell. Their composition and content depend on physiological state, abiotic environmental factors, and a developmental phase of the organism. Their functions in plants are very diverse; those include participation in both the synthesis of proteins and other compounds and the adaptation to adverse environmental conditions. Information on the FAA dynamics is of key importance for understanding their role in formation of algae resistance to varying environmental factors. The aim of this study is to determine the FAA content in the brown alga <em>Fucus vesiculosus</em> and its seasonal changes, as well as to reveal the dependence on environmental factors and the alga developmental phase. The alga for research was sampled in the Kola Bay littoral (the Barents Sea) during low tide once a month from December 2015 to December 2016. The middle part of the thallus was used for the study. The FAA qualitative and quantitative composition was determined by high-performance liquid chromatography. The FAA qualitative composition did not change throughout the year; in the FAA pool, glutamic and aspartic acids, alanine, and proline prevailed. The FAA content varied throughout the year; the maximum amount was recorded in spring–summer. The FAA content depended on external environmental factors. The correlations were determined between the content of individual FAA and air temperature, water temperature, and salinity. The FAA dynamics in different developmental phases of <em>F. vesiculosus</em> was associated with processes occurring in the alga; it is affected by growth rate, cell metabolic activity, photosynthesis rate, and generative development. Each phase was characterized by its own dynamics of the FAA content. Based on the dynamics of the FAA concentration in <em>F. vesiculosus</em>, correspondences were found with the developmental phases – dormancy, growth activation, growth, and storage. Free glutamate and aspartate may act as one of the reserve sources of organic nitrogen in this alga. Apparently, the transport of organic forms of nitrogen in <em>F. vesiculosus</em> thallus is carried out by glutamate, aspartate, alanine, and proline.</p> M. P. Klindukh Copyright (c) 2022 A. O. Kovalevsky Institute of Biology of the Southern Seas of RAS 2022-09-13 2022-09-13 7 3 44 59 Trichoplax sp. H2 cultivation and regeneration from body fragments and dissociated cell aggregates: Outlook for genetic modification <p><em>Trichoplax</em> sp. H2, a simple multicellular animal cultivated in the laboratory, was studied with the aim of its further genetic modification. The idea here is to introduce genetic information into a cell suspension after dissociation of the <em>Trichoplax</em> body into single cells, followed by their aggregation and regeneration of the resulting agglomerates into a viable animal. 1. We analyzed the dynamics of the <em>Trichoplax</em> growth in Petri dishes on <em>Tetraselmis marina</em> algal mats. Specimens were uniform on the exponential growth stage. 2. Trichoplaxes were cut radially in a post-traumatic regeneration research, and the regeneration of the obtained parts was investigated under a microscope. Growth and reproduction rate of animals on nutrient mats were determined that decreased as the animals had been cut. The missing part of the <em>Trichoplax</em> body was replaced by remodeling of remaining cells. 3. The animals after a vital staining were dissociated into single cells in a medium with no divalent cations. Pear-shaped or rounded cells were identified, as well as epithelial cells with flagella maintaining motion activity for more than 12 hours. 4. <em>Trichoplax</em> plates were disintegrated in the presence of 10 μM amlodipine to quantify a cell population using flow cytometry. As estimated, <em>Trichoplax</em> (0.5–1 mm in size) consists of approximately 10,000 cells. 5. Treatment of animals with 10 % BSA (Bovine Serum Albumin) during various exposure intervals suggests a hypothesis on the existence of totipotent cells at the periphery of the <em>Trichoplax</em> body, probably in the rim. 6. In the course of reparative regeneration experiments, we achieved <em>Trichoplax</em> dissociation into single cells with 0.1 % BSA treatment and the following recreation of the viable organisms by centrifugation of a cell suspension and subsequent dispersion of a large pellet into fragments up to 0.1 mm <em>prior</em> to plating multicellular aggregates on nutrient mats. 7. The development of the aggregates was accompanied by active motion of cells and epithelialization of the surface, which resulted in cell growth, formation of a plate, and further vegetative division of <em>Trichoplax</em>. As assumed, the artificial stage of a single cell in a line of asexual reproductions allows to introduce foreign genetic information into <em>Trichoplax</em>, for example, in order to study the signal processing, organization, and functioning of this multicellular organism. Transgenesis, which is based on the dissociation of an animal body into single cells, could be applied to other organisms with high regenerative potential.</p> A. V. Kuznetsov V. I. Vainer Yu. M. Volkova V. M. Tsygankova D. N. Bochko V. S. Mukhanov Copyright (c) 2022 A. O. Kovalevsky Institute of Biology of the Southern Seas of RAS 2022-09-13 2022-09-13 7 3 60 79 Preservation of biological diversity by cryopreservation methods: Experience of the Southern Scientific Center of the RAS <p>One of the promising directions for increasing animal genetic diversity is the formation of cryobanks and long-term storage of reproductive cells in liquid nitrogen. Methods of sperm cryopreservation are known for more than 200 fish species. The resistance to sperm cryodamage in different fish species varies dramatically. There is no unified cryopreservation technique for fish since the habitats vary greatly for different species. In Russia, cryopreserved sperm is currently used extremely insufficiently in aquaculture, but the practice dictates the need for widespread use of cryosperm to solve the problems of producing high-quality fish seed material and for breeding work. The formation of cryobanks is very relevant due to extensive development of aquaculture. Providing commercial and farm enterprises with elite genetic material capable of reproduction at any time of the year will allow not only to set up a biotechnological process, but also to eliminate inbreeding.</p> E. N. Ponomareva A. A. Krasilnikova M. M. Belaya M. V. Kovalenko Copyright (c) 2022 A. O. Kovalevsky Institute of Biology of the Southern Seas of RAS 2022-09-13 2022-09-13 7 3 80 87 Benthic algae communities of coral reefs in the Sanya Bay (Hainan Island, China) in sites heavily polluted with nutrients and their changes after the pollution source elimination <p>It was previously found that extremely high concentrations of nutrients in seawater in the polluted area of a fish farm on the Luhuitou Peninsula (the Sanya Bay) cause a significant reduction in species diversity and abundance of low-productive annual and perennial red and brown algae, as well as an increase in number and biomass of highly productive green algae. In 2017–2019, for the first time, we studied changes in the number and structure of benthic algal communities over a range of tidal zones in the Sanya Bay after the pollution source elimination – the fish farm liquidation. It was shown that a decrease in the concentration of dissolved inorganic nitrogen (DIN) (from ≈ 20 to 2.5 μM) and orthophosphates (from 5.0 to 0.2 μM) in seawater significantly altered diversity, species composition, and structure of benthic algal communities. One and half years after the pollution source elimination, the main indicators of the flora became, on average, close to those of the moderately polluted areas of the Sanya Bay.</p> E. A. Titlyanov T. V. Titlyanova X. Li O. S. Belous H. Huang Copyright (c) 2022 A. O. Kovalevsky Institute of Biology of the Southern Seas of RAS 2022-09-13 2022-09-13 7 3 88 102 Competitive advantages of the diatom Skeletonema costatum Cleve, 1873 in the Black Sea in the winter–spring period <p>Individual physiological features of the <em>Skeletonema costatum</em> vegetation under low light intensity and low temperature are described; these peculiarities allow the species to prevail in the Black Sea phytoplankton in winter and early spring. This marine diatom is characterized by high growth efficiency under light-limiting conditions (0.13 day<sup>−1</sup>·(µE·m<sup>−2</sup>·s<sup>−1</sup>)<sup>−1</sup>) which indicates an increase in the specific growth rate of the alga with a rise in light intensity by 1 µE·m<sup>−2</sup>·s<sup>−1</sup>. Moreover, the species is characterized by low values of the light intensity saturating the growth – 12 µE·m<sup>−2</sup>·s<sup>−1</sup> at +5 °C and 18 µE·m<sup>−2</sup>·s<sup>−1</sup> at +10 °C. At +5…+10 °C, <em>S. costatum</em> growth rate is about 2 times higher than that of other representatives of the Black Sea phytoplankton in the winter–spring period. This diatom shows increased sensitivity to high light intensity: at +10 °C, photoinhibition of microalgae growth is observed under light intensity above 120 µE·m<sup>−2</sup>·s<sup>−1</sup>.</p> N. Yu. Shoman A. I. Akimov Copyright (c) 2022 A. O. Kovalevsky Institute of Biology of the Southern Seas of RAS 2022-09-13 2022-09-13 7 3 103 106