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, ISSN 2499-9776 online.</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 In memoriam: Nikolai Risik (07.08.1937 – 11.12.2021) // <p>On 11 December, 2021, PhD Nikolai Risik passed away – a well-known radiobiologist and one of the oldest employees of the IBSS radiation and chemical biology department. N. Risik is the author of more than 70 scientific articles and co-author of five collective monographs.</p> Copyright (c) 2022 A. O. Kovalevsky Institute of Biology of the Southern Seas of RAS 2022-03-22 2022-03-22 7 1 110 112 Production characteristics of Porphyridium purpureum (Bory) Drew et Ross semi-continuous culture at low irradiance // <p>The red microalga <em>Porphyridium purpureum</em> (Bory de Saint-Vincent, 1797) Drew et Ross, 1965 is of great interest to researchers as a source of various biologically valuable substances, with their content in cells being determined by cultivation conditions. Phycobiliproteins concentration in <em>P. purpureum</em> cells depends directly on nitrogen concentration in the culture medium and cell irradiance. Semi-continuous cultivation allows maintaining these parameters at a level given. The aim of the work was to study <em>P. purpureum</em> culture growth and B-phycoerythrin (B-PE) accumulation and production at low irradiance, with minimal rates of pigment photodestruction. <em>P. purpureum</em> semi-continuous (quasi-continuous) cultivation was carried out at a specific flow rate of 0.1 and 0.2 day<sup>−1</sup> and mean surface irradiance of 5 and 25 W·m<sup>−2</sup>. <em>P. purpureum</em> culture productivity increased by 1.6–17 times both with a rise in surface irradiance 5 to 25 W·m<sup>−2</sup> and an increase in the medium specific flow rate 0.1 to 0.2 day<sup>−1</sup>. Maximum productivity values for the experimental conditions (0.21 g·L<sup>−1</sup>·day<sup>−1</sup>) were recorded at 25 W·m<sup>−2</sup> and 20 % medium specific flow rate, but those were 1.5–2 times lower than the precalculated ones. In <em>P. purpureum</em> cells, protein and B-PE concentrations decreased both with an increase in surface irradiance (by 15–20 %) and with a rise in a specific flow rate (by 1.5 times) for all the variants. The shifts in protein and B-PE concentration in <em>P. purpureum</em> culture had a unidirectional character as well; those mainly corresponded to the shift in the culture density. <em>P. purpureum</em> B-PE productivity increased by 1.5–1.9 times with a rise in surface irradiance 5 to 25 W·m<sup>−2</sup>. Maximum B-PE productivity (13 mg·L<sup>−1</sup>·day<sup>−1</sup>) was recorded for the variants of the experiment with a surface irradiance of 25 W·m<sup>−2</sup> (0.1 and 0.2 day<sup>−1</sup>). An increase in specific irradiance of <em>P. purpureum</em> cells 7 to 26 W·g<sup>−1</sup> resulted in a rise in biomass productivity by 2.6 times; in B-PE productivity, by 1.8 times; and in protein productivity, by 1.7 times. In the experiment, irradiance was the factor determining the production characteristics of <em>P. purpureum</em> culture, and it was confirmed by the data obtained.</p> A. B. Borovkov I. N. Gudvilovich T. M. Novikova E. V. Klimova Copyright (c) 2022 A. O. Kovalevsky Institute of Biology of the Southern Seas of RAS 2022-03-22 2022-03-22 7 1 3 13 10.21072/mbj.2022.07.1.01 Pathomorphological and biochemical study of the golden grey mullet Chelon auratus (Risso, 1810) in the waters of the southwestern Crimea (the Black Sea) // <p>The golden grey mullet <em>Chelon auratus</em> (Risso, 1810) (Mugilidae) is a valuable commercial and recreational species ranking first in terms of catch volume of the Black Sea indigenous mullets. The importance of this species in the regional fishery among demersal fish requires the development of a system for assessing its health status. Such research is based on an integrated approach involving biochemical and pathomorphological methods: these allow to investigate the alterations in fish <em>prior</em> the occurrence of visible manifestations, disruption of the processes of growth and reproduction, reduction of commercial size, and decrease in abundance. The aim of our work was to study both pathomorphological alterations and several biochemical parameters of golden grey mullet tissues for assessing its health status. Fish visual examination and pathological autopsy were carried out. For histological analysis, samples of the gills, liver, kidneys, gastrointestinal tract, spleen, and pancreas were fixed in Davidson’s solution and processed by standard methods. Based on the histological studies, the fish health status was investigated by a modified semi-quantitative analysis of alterations according to the Bernet <em>et al.</em> protocol and by assessing the distribution of lesion in organs using a scoring system. We determined the importance factors of alterations for <em>C. auratus</em>, the values of organ alteration indices, and the total index of fish pathology. The biochemical studies permitted to reveal the level of protein oxidation, lipid and urea peroxidation, and the activity of aminotransferases and alkaline phosphatase in the liver; moreover, we quantified albumin and glucose concentration in the blood serum. In the organs of the golden grey mullet, the histopathological alterations referring to four types of the reaction patterns were detected (circulatory disorders, regressive and progressive alterations, and inflammatory processes). Furthermore, parasites representing several species of different systematic groups (Protozoa, Monogenea, Trematoda, and Nematoda) were identified. It was established that the most severe histopathological alterations were caused by a parasitic protozoan, presumably <em>Ichthyophonus</em> sp. When carrying out a semi-quantitative analysis of alterations, the mullets were conventionally divided into conditionally healthy individuals and infected ones. Pathomorphological data were obtained, and the set of biochemical parameters was compared in these two groups. Significant differences were revealed in the values of organ alteration indices in <em>C. auratus</em> in the kidneys, liver, gastrointestinal tract, and pancreas. The values of the total index of fish pathology also differed significantly. The biochemical studies revealed a significant increase in urea content in the liver of fish from the group 2, that may indicate the kidney and gill excretory dysfunction (it was confirmed histologically). No significant differences were found in the level of lipid peroxidation, protein oxidation, and activity of aminotransferases in the liver of conditionally healthy and infected fish. The results of our investigation confirm high informativeness of the studied parameters for assessing the health status of the golden grey mullet.</p> T. V. Gavruseva T. B. Sigacheva I. I. Chesnokova Copyright (c) 2022 A. O. Kovalevsky Institute of Biology of the Southern Seas of RAS 2022-03-22 2022-03-22 7 1 14 33 10.21072/mbj.2022.07.1.02 Taxonomic diversity of Amphipoda (Crustacea) from the Black Sea and the Sea of Azov // <p>In the Black Sea and the Sea of Azov, 140 Amphipoda species were registered belonging to 73 genera, 29 families, and 3 suborders. Taxonomic diversity of amphipods from these two seas was studied. For the investigation, average taxonomic distinctness Δ<sup>+</sup> and its variability Λ<sup>+</sup> were used, and cluster analysis and multidimensional scaling were applied. By Δ<sup>+</sup> index, the taxonomic structure of the Black Sea and the Sea of Azov Amphipoda is hierarchically aligned and close to a total taxonomic list of amphipods of these seas. By Λ<sup>+</sup> index, the taxonomic structure of Amphipoda both from the Sea of Azov and the Black Sea is close to the average expected level of structure variability of the phylogenetic tree. In the coastal areas of Turkey and Crimea, more Amphipoda species were recorded than in other regions. Out of the Black Sea regions studied by Δ<sup>+</sup> and Λ<sup>+</sup> indices and multidimensional scaling, two, <em>i. e.</em> northwestern coast and eastern coast (Caucasus), were selected as different ones. The first one is characterized by low taxonomic diversity due to a small number of genera and families against the backdrop of a significant number of species of the Ponto-Caspian fauna. It is associated with the presence of estuaries of large rivers and freshened lagoons. On the contrary, the Black Sea eastern coast is characterized by high taxonomic diversity against the backdrop of a small number of species. It is associated mostly with weak shelf manifestation and close slope of depth, with loose soils being poorly represented. Cluster analysis confirmed that these two Black Sea regions, <em>i. e.</em> northwestern coast and eastern coast, differ from other ones. Moreover, by cluster analysis, the similarity of Amphipoda taxonomic composition for the Black Sea northwestern coast and the Sea of Azov was revealed. Out of all the amphipods, Ponto-Caspian species stand out which inhabit predominantly estuaries of large rivers and freshened lagoons. Those are characterized by a taxonomic structure shifted in terms of taxonomic evenness towards impoverishment; it is due to a small number of genera and families against the backdrop of a significant number of species.</p> V. A. Grintsov Copyright (c) 2022 A. O. Kovalevsky Institute of Biology of the Southern Seas of RAS 2022-03-22 2022-03-22 7 1 34 45 10.21072/mbj.2022.07.1.03 Morphological features of three species of Phyllodistomum (Trematoda: Gorgoderidae) from some marine fishes in the southern Black Sea // <p>Three species of the genus <em>Phyllodistomum</em> Braun, 1899 are identified infecting marine teleost fishes from Sinop coast (southern Black Sea, Turkey). Those are <em>Phyllodistomum acceptum</em> from <em>Parablennius sanguinolentus</em>; <em>Phyllodistomum</em> <em>crenilabri</em> from <em>Symphodus tinca</em> and <em>Symphodus ocellatus</em>; and <em>Phyllodistomum</em> sp. from <em>Gobius cruentatus</em>. Standard parasitological investigation methods were implemented, and morphological diagnostic features of these species were studied in detail under both light microscope and scanning electron microscope. The measurement data of all morphological diagnostics are provided; photomicrographs of each part of the parasites are presented. Infection prevalence and intensity values are given, as well as morphometric data for each parasite species. This research is the first on <em>Phyllodistomum</em> sp. presence in <em>Gobius cruentatus</em>. Moreover, this study is the first one, in which the tegumental surface of <em>P. acceptum</em> and <em>P. crenilabri</em> was examined by scanning electron microscopy.</p> A. Güven T. Öztürk Copyright (c) 2021 A. O. Kovalevsky Institute of Biology of the Southern Seas of RAS 2022-03-22 2022-03-22 7 1 46 54 10.21072/mbj.2022.07.1.04 Activity of peptidases and glycosidases of the digestive tract in some species of bony fish of Vietnam // <p>For the first time, the activity and pH dependence of digestive enzymes were studied in fish inhabiting the Mekong Delta: duskyfin glassy perchlet <em>Parambassis wolffii</em>, smallscale croaker <em>Boesemania microlepis</em>, catfish <em>Pangasius macronema</em>, and representatives of the family Cyprinidae. Significant interspecific differences were revealed in the level of peptidase and glycosidase activity providing hydrolysis of protein and carbohydrate food components. The greatest interspecific differences are characteristic of glycosidases: the level of enzymatic activity in Cyprinidae fish exceeds that in <em>P. wolffii</em> by 13.6 times. The differences in the level of peptidase activity in fish of different species are lower: in the case of the activity of stomach enzymes in <em>P. wolffii</em>, the values are 1.8 times higher than those in <em>P. macronema</em>, and in the case of total activity of stomach and intestinal enzymes in the same species, the values are 1.5 times higher. The data obtained confirm the concept that the digestive hydrolase activity depends on the fish feeding spectrum. The activity of intestinal enzymes decreases more significantly in the acidic pH zone than in the basic one. Consequently, acidification of the intestinal environment will negatively affect the digestive processes in these fish species.</p> V. V. Kuz’mina E. E. Slynko E. A. Kulivatskaya E. P. Karpova Dinh Cu Nguyen Copyright (c) 2022 A. O. Kovalevsky Institute of Biology of the Southern Seas of RAS 2022-03-22 2022-03-22 7 1 55 64 10.21072/mbj.2022.07.1.05 Variability in the number of rays and specification of the dorsal fin formula of the black scorpionfish Scorpaena porcus Linnaeus, 1758 (Pisces: Scorpaenidae) from the Black Sea // <p>Out of the morphological criteria for the fish species, the meristic (countable) characters are of the key role, in particular the number of rays in the fins. It is one of the stable signs of fish morphotype not subjected to size and age variability. At the same time, it is a clear taxonomic criterion. The aim of the work was to study the variability in the number of rays in the dorsal fin and to specify its formula for the black scorpionfish inhabiting the Black Sea off the coasts of the North Caucasus and Crimea. In total, 232 individuals of the black scorpionfish were investigated; those were sampled from six areas of the Black Sea off the coasts of the North Caucasus (Bolshoi Utrish, Magri, Loo, and Adler) and Crimea (Sevastopol and Feodosiya). The number of rays in the dorsal fin of each fish was counted, with dividing them into hard (unbranched) and soft (branched) ones. As established, the total number of rays in the dorsal fin of the black scorpionfish inhabiting the coasts of the North Caucasus and Crimea averaged (22.1 ± 0.02); the number of hard rays, (12.0 ± 0.01); and the number of soft rays, (10.1 ± 0.03). All three indicators are characterized by low variability (coefficient of variation is lower than 10 %). Fish caught off the coasts of the North Caucasus and Crimea differ statistically significantly from each other in the number of soft rays in the dorsal fin [(10.1 ± 0.03) and (10.0 ± 0.04), respectively] and in the total number of rays in the dorsal fin [(22.1 ± 0.03) and (22.0 ± 0.04), respectively]. The analysis of the results obtained reveals six possible variants of the dorsal fin formula for the black scorpionfish. Those are: D XI 10; D XI 11; D XII 9; D XII 10; D XII 11; and D XIII 10. The most common variant is D XII 10 averaging 83.2 % (75.0–88.9 % depending on the area). The updated dorsal fin formula for the black scorpionfish inhabiting the coasts of the North Caucasus and Crimea has the following form: D (XI) XII (XIII) (9) 10 (11). The formula can be used when compiling the species guides of the Black Sea fish. The results obtained were compared with those of other researchers. The causes for the disagreement between the results were analyzed.</p> A. A. Polin A. N. Pashkov T. V. Denisova Copyright (c) 2022 A. O. Kovalevsky Institute of Biology of the Southern Seas of RAS 2022-03-22 2022-03-22 7 1 65 77 10.21072/mbj.2022.07.1.06 Wind effect on zooplankton distribution in the estuary of the Pregolya River (the Baltic Sea basin) after technogenic transformation of its riverbed // <p>In 2014–2018, large-scale hydrotechnical works were carried out in the estuary of the Pregolya River. The structural changes in the summer zooplankton in the river mouth in 2019 were revealed in comparison with the data obtained <em>prior</em> the riverbed transformation. In June 2019, zooplankton total abundance and biomass were of (136 ± 111) thousand ind.·m<sup>−3</sup> and (860 ± 840) mg·m<sup>−3</sup>, respectively. It is comparable with mean annual data of 1996–2006: (71 ± 66) thousand ind.·m<sup>−3</sup> and (664 ± 337) mg·m<sup>−3</sup>, respectively. In the summer of 2019, for the first time, the euryhaline species <em>Eurytemora affinis</em> inhabiting the Vistula Lagoon was recorded in the Novaya Pregolya branch. The presence of this species in the river branches, as well as the values of water salinity, may result from an increase in the frequency or intensity of water surges into the river from the Vistula Lagoon. In this regard, the wind conditions in 1998–2006 and 2011–2019 were analyzed. In 2011–2019, there was no increase in the frequency of winds acting along the effective surge direction (southwest and west ones) compared with those in 1996–2006. However, a rise in the frequency of storms was noted, <em>inter alia</em> in summer. Westerly storm winds cause upstream water inflow from the Vistula Lagoon and channel. Probably, the destruction of river macrophyte communities, concreting of embankments, and a change in the channel bottom configuration affected the intensity of water inflow from the lagoon into the river branches during surges and became the main factor affecting the distribution of euryhaline species from the lagoon in the river branches.</p> Ju. Ju. Polunina Zh. I. Stont Copyright (c) 2022 A. O. Kovalevsky Institute of Biology of the Southern Seas of RAS 2022-03-22 2022-03-22 7 1 78 92 10.21072/mbj.2022.07.1.07 Trophic relationships in the zooplankton – gelatinous zooplankton food chain in the shelf areas of the Crimean coast of the Black Sea // <p>The seasonal and spatial dynamics of the key trophic characteristics were studied (food spectrum, feeding rate, and predatory impact on mesozooplankton) for populations of the jellyfish <em>Aurelia aurita</em> (Linnaeus, 1758) and ctenophore <em>Mnemiopsis leidyi</em> A. Agassiz, 1865. The investigation was carried out during four cruises of the RV “Professor Vodyanitsky” in the shelf areas of Crimean Peninsula in January to October 2016. The area was divided into inner (depth of &lt; 50 m) and outer (51–150 m) shelves. To study the food spectrum and feeding rate of gelatinous predators, the composition of food items in the gastric cavity was analyzed under a binocular microscope. Daily ration (R, mg C·ind.<sup>−1</sup>·day<sup>−1</sup>) was calculated by the formula: R = B<sub>z</sub> × DT<sup>−1</sup> × 24, where B<sub>z</sub> is zooplankton biomass in the predator gastric cavity (mg), and DT is zooplankton digestion time (h). Predatory impact of gelatinous zooplankton was estimated by the values of daily ration and mesozooplankton biomass. Zooplankton was sampled with a Juday plankton net with mouth diameter of 38 cm and mesh size of 140 µm. Vertical net hauls were performed: at the inner shelf stations, from the sea surface down to the bottom; at the outer shelf stations, down to the boundary of the hydrogen sulfide zone (δ<sub>t</sub> = 16.2 conventional units according to a Sea-Bird probe). In the samples fixed with 4 % formalin solution, zooplankton abundance, its taxonomic composition, and size–age structure were quantified by standard method. In the food spectrum of the jellyfish, seasonal differences were revealed: predominance of Bivalvia veligers in winter and spring and wide species composition of Crustacea and other groups of prey in summer. The feeding rates of the studied species were similar: specific daily rations in winter, spring, and autumn did not exceed tenth of a percent of the carbon content in the body. Both species fed at a maximum rate in summer on the outer shelf: the specific rations reached 12.9 and 5.1 % C of the body for the jellyfish and ctenophore, respectively. <em>A. aurita</em> and <em>M. leidyi</em> populations consumed 0.2 to 5 % of the fodder zooplankton biomass <em>per</em> day; it did not result in a drastic reduction in zooplankton abundance and provided favorable feeding conditions for small planktivorous pelagic fish.</p> G. A. Finenko N. A. Datsyk B. E. Anninsky Yu. A. Zagorodnyaya Copyright (c) 2022 A. O. Kovalevsky Institute of Biology of the Southern Seas of RAS 2022-03-22 2022-03-22 7 1 93 106 10.21072/mbj.2022.07.1.08 Outbreak of marine mucilage in the Sea of Marmara in 2021 // <p>An outbreak of marine mucilage in the Sea of Marmara in the spring and summer of 2021 is described. Based on satellite data, an analysis of similar outbreaks in the previous decade was carried out. As shown, the current situation is unique both in terms of the water area coverage and phenomenon duration. The need for comprehensive research is emphasized in order to understand the causes of the occurrence of the marine mucilage and the consequences of its effect on the marine ecosystem and economic activities in coastal waters.</p> A. V. Medvedeva S. V. Stanichny Copyright (c) 2022 A. O. Kovalevsky Institute of Biology of the Southern Seas of RAS 2022-03-22 2022-03-22 7 1 107 109 10.21072/mbj.2022.07.1.09