bluuebunny/crossref_metadata_2025 huggingface dataset:
Distribution of Dragon Poacher Percis japonica (Agonidae) in the Russian Territorial Waters in the Sea of Japan
Authors: Solomatov S. F. , Antonenko D. V.
Published: April 2024

The research outcomes of spatial and bathymetric distribution of dragon poacher Percis japonica are reported based on the bottom trawl surveys carried out in the Russian territorial waters in the Sea of Japan. The species can be found in the waters along the entire coastline. However, its spatial distribution pattern is variable. Thus, its distribution is sparse off the coasts of West Sakhalin, especially off the southern part of the island, while the species tends to congregate in the Peter the Great Bay and the Tatar Strait, where the locations of the species across these water areas remain almost unchanged throughout the year. With respect to the Northern Primorye Coastal Zone, the even distribution is typical for the entire water area, without any high congregation locations. Therefore, the dragon poacher can be found in wide ranges of depths and temperatures. However, its preferable ranges are substantially narrower. The highest values for available biomass resources are typical for the water areas off the Northern Primorye Coastal Zone.
Vertebral Column Variation of Mudskippers (Gobiidae: Oxudercinae): Early Stages of Water-to-land Transition
Authors: Tran L. X. , Nguyen T. T.K. , Vo T. T.
Published: April 2024

Carrying a gravitational load requires modifications of the skeletal system during water-to-land transition of vertebrates. Early stages of the transition are little known due to incomplete and scattered fossil deposits which can be fulfilled by examining extant amphibious fishes facing analogous conditions. In the present study, we compared vertebral morphometrics of eight oxudercine gobies (Parapocryptes serperaster, Pseudapocryptes elongatus, Oxuderces nexipinnis (low terrestrial); Boleophthalmus boddarti and Scartelaos histophorus (moderate terrestrial), Periophthalmus chrysospilos, Periophthalmodon schlosseri, and Periophthalmodon septemradiatus (high terrestrial)) to gain understanding of the vertebral modifications during land invasion. Results show that the higher terrestrial species possess higher flexibility of the vertebral column, heavy ossification of the neural and haemal spines in the caudal region, and the dorsal twisting feature of the caudal base which could serve effective terrestrial locomotion and allow to perform various body postures. The flexibility of the anterior portion of the caudal region could serve the tail standing and leaping of some mudskippers. We tentatively presume that terrestrial locomotion of oxudercine gobies is endowed by flexibility of the vertebral column and heavy ossification of the caudal vertebrae.
Predictions about the Pink Salmon Oncorhynchus gorbuscha (Salmonidae) Catches on Iturup Island
Authors: Zelennikov O. V. , Myakishev M. S.
Published: April 2024

The pink salmon Oncorhynchus gorbuscha spawners which otolith marks created at fish early age at the Kurils and Reidov fish-rearing stations have been studied; fish breeding data and fishing statistics have been analyzed. At the end of the spawning run of pink salmon, only fish of the fish-farm origin have been caught near the fish-rearing stations. More than that, the pink salmon spawners return to the stations of their release (although with rare exceptions). The catches of the pink salmon on Iturup Island are on average 1.6 times greater in even years than in odd years. The increase of the fish stock in odd years significantly depends on the breeding of juveniles in fish farms. There is a positive statistically significant relationship between the filling of spawning grounds with pink salmon spawners and its catches in the Prostor and Kurilsky bays two years later.
Comparison of Taste Reception and Feeding Behavior of the Nile Tilapia Oreochromis niloticus (Cichlidae) of Different Age
Authors: Kasumyan A. O. , Levina A. D.
Published: April 2024

Comparison of specimens of the Nile tilapia Oreochromis niloticus of two age groups did not show any significant differences. L-cysteine, L-lysine and citric acid have an attractive taste for juveniles (age 1.5 months, body length 6.5–7.0 cm, weight 5–7 g); L-cysteine and citric acid have an attractive taste for adult fish (4 months, 12–15 cm, 45–50 g). The other eight L-amino acids have an indifferent taste for fish of both age groups. Based on the data obtained and the results of other studies, a hypothetical scheme is proposed, according to which the fastest functional transformations of taste reception in fish ontogeny occur after the start of exogenous feeding of larvae and are completed before maturation. Fish of both age groups rarely re–grasp pellets flavored with taste substances, but juveniles spend much more time on pellets orosensory evaluation, up to 1.4–1.6 times. Regardless of the fish age, such an assessment requires more time if the testing of pellets ends with their ingestion. The differences may indicate an undeveloped stereotype of feeding behavior in juveniles of Nile tilapia.
Direct Ageing and Growth using Dorsal Fin Spines of Bluefin Tuna Thunnus thynnus (Scombridae) Reared in Sea Cages and a Comparison with Wild Populations
Authors: Milatou  N. , Megalofonou P.
Published: April 2024

The main objectives of this study were to estimate the age and growth of reared Atlantic bluefin tuna and to reveal possible differences in growth between reared and wild specimens. A total of 806 specimens, ranging from 102 to 284 cm in length, were sampled from a Greek tuna farm in the Mediterranean Sea. The first spine of the first dorsal fin was used to estimate the age. Estimated ages ranged from 3 to 20 years, and the reproducibility of the ageing method was high. The proportion of the mean number of missing annuli per age due to vascularization ranged from 27.8 to 40.0%, with an average loss of 33.5%. No significant differences in the number of missing annuli were observed between 6–month and 18–month reared specimens of the same age group. The von Bertalanffy growth model was fitted a) to mean FL-at-age data and b) to mean RW-at-age data, and the growth equations found were: Lt = 296.6[1 – e(−0.114) (t + 1.026)] and Wt = 591.6[1 – e(−0.100)(t + 1.755)]3. Our results showed that the rearing process accelerates the growth of the Atlantic bluefin tuna and this was also evident in the calcified structure. In comparison with previous studies of growth in wild bluefin tuna from the Mediterranean Sea, mean weights at age of the reared fish were higher than those from wild fish in all age groups and lengths at age of the reared bluefin tuna were higher in younger fish, up to 6 years old.
Comparative Analysis of the Morphological Diversity Structure of Altai Osmans of the Genus Oreoleuciscus (Cyprinidae) in the Riverine Populations of Three Mongolian Water Systems
Authors: Mironovsky A. N. , Slynko E. E.
Published: April 2024

Analysis of the structure of the morphological diversity of the Altai osmans of the genus Oreoleuciscus in the Urt River (water system of the Tes River) indicates that this is a polymorphic population, consisting of three forms, clearly differentiated by a set of characters. The ratio of differences between these forms and forms previously identified in the Zavkhan (water system of the Great Lakes Hollow) and Tuin (water system of the Lake Valley) rivers suggests that the characters considered in the study are adaptively plastic, and the revealed structure of the morphological diversity of the genus is mostly determined by local patterns of environmental conditions.
Genetic Variations of Fourth Exon Region of Prolactin Gene and Its Associations with Growth Traits in European Sea Bass Dicentrarchus labrax (Moronidae)
Authors: Özcan-Gökçek E. , Işık R.
Published: April 2024

European sea bass Dicentrarchus labrax (Moronidae), which has a high commercial value, is mainly produced in the Mediterranean region. Prolactin (PRL) is a member of the helix bundle protein family that is secreted in the anterior pituitary gland and has a significant role in osmoregulation and growth in teleost fish. In this study, we investigated the genetic variation of the partial sequence of 3rd, 4th introns, and 4th exon regions of the PRL gene in Dicentrarchus labrax and its association with growth traits that were reared in cage conditions. Two SNPs (g.484 A C, g.529 T C) and one 15 bp indel (insertion/deletion) have been found in the 3rd intron region of the PRL gene of Dicentrarchus labrax. A significant association has been identified between the total body weight and the genotypes for PRL g.529 T C locus (р 0.05). The heterozygote genotype of the PRL g.529 T C locus has a significantly higher total body weight than the other genotypes in the population (p 0.05). Association analysis indicated that this SNP in the PRL gene is correlated with growth traits and could be used for genomic selection programs in Dicentrarchus labrax breeding.
Effects of Salinity on Lipid Composition in Juvenile Pinc Salmon Oncorhynchus gorbuscha (Salmonidae)
Authors: Vasileva O. B. , Efremov D. A. , Ruokolainen T. R. , Nemova N. N.
Published: April 2024

Lipid and fatty acid modifications induced by the effects of various salinity patterns on the juvenile pink salmon Oncorhynchus gorbuscha (the Olkhovka River and the White Sea) within the experiment have been revealed. Concentrations of steroids, saturated fatty acids, and signaling molecules such as phospholipids (phosphatidylserine and phosphatidylinositol) and arachidonic acid under the hyperosmotic stress-related effects (keeping the fish for 1 h in the seawater after the time of transfer from the freswater) tend to increase. Decreases in phosphatidylcholine and n-6 saturated, monounsaturated, and polyunsaturated fatty acids are recorded in the juvenile pink salmon fish kept for 24 h in the seawater after the time of transfer them from the freswater, while the levels of phosphatidylethanolamine and n-3 polyunsaturated fatty acids (especially eicosapentaenoic and docosahexaenoic acids), on the contrary, tend to rise significantly. Lipid composition modifications in the juvenile pink salmon fish kept under the hypoosmotic stress conditions (24 h in freshwater after 24 h in seawater) induce stabilization of functioning the cell membrane structure, since the levels of bioeffectors including phosphatidylserine, phosphatidylinositol, and arachidonic, eicosapentaenoic, and docosahexaenoic acids tend to decrease. A reduced amount of lipids (triacylglycerols) stored as an energy reserve is shown for all the experimental fish groups. The outcomes indicate the high levels of adaptive potential of the juvenile pink salmon fish kept under the effects of abrupt salinity change in the water environments and their readiness for downstream migration not long before leaving the nests.
Hunting of the Reef Needlefish Strongylura incisa (Belonidae) for Small Schooling Pelagic Fishes on Shallow Lagoonal Reefs of Innafushi Mini-Atoll (Indian Ocean, Maldives, Ari Atoll)
Authors: Astakhov D. A.
Published: April 2024

The tactics of the reef needlefish Strongylura incisa while hunting for small schooling pelagic fishes is described and photographically documented for the first time. Small flocks of reef needlefish enter the lagoon of the mini-atoll through passages in the reef at the beginning of the tide to hunt small schooling pelagic fishes, which move over the reef into the lagoon of the mini-atoll. In the lagoon, needlefish spread, and part of the flock (only a few) enter the reef itself, while the main part of the flock continues to move along the edge of the lagoonal reef in the direction of schools of small pelagic fishes moving through the reef and cuts the schools into supra-reef and lagoonal parts. Then the reef needlefish move onto the reef and begin to solitary hunt prey at a depth of only 10–15 cm. At such an insignificant depth a school of small pelagic fish loses the ability to turn synchronously. When attacking by a reef needlefish, members of the former school make individual chaotic movements and thereby become easier prey for the needlefish. However, hunting in shallow reef waters poses risks of collision with coral branches on the bottom for the reef needlefish.
New Species of the Genus Argyripnus (Sternoptychidae) from the Pacific Ocean
Authors: Prokofiev A. M.
Published: April 2024

A new species of maurolicid hatchetfish of the genus Argyripnus from the Bonin Ridge in the northwestern part of the Pacific Ocean has been described. A. scharpfi sp. nov. is most similar to A. atlanticus, but differs in smaller and more numerous maxillary teeth, the absence of a noticeable gap between the last photophore of the lateral row and the first photophore of the ventroanal row, the anus close to the anal-fin origin, and, possibly, some meristic and morphometric characters, for the verification of which additional material is necessary. The genus Argyripnus was recorded for the first time on the Bonin Ridge.
Fish Species Composition of Bottom Gillnet Catches by Japanese Fishing Vessels Operated in Russian Zone of Kunashir Strait in 1998–2014
Authors: Velikanov  A. Ya. , Mukhametov I. N.
Published: April 2024

Overall, 85 fish species assigned to 56 genera, 27 families, and 13 orders were observed in the bottom net catches from the Kunashir Strait in 1998–2014. The highest number of species (18) represented the family Pleuronectidae, while the family Cottidae involved the lower number of species (14). Thus, 35 species were found in the Nemuro Strait (including the Kunashir Strait) for the first time. Considering the information in the literature, the total number of fish species in the strait separating the Southern Kuril Islands from the Hokkaido Island increased to 173.
Biochemical Differentiation in Embryos and Larvae of the Atlantic Salmon Salmo salar (Salmonidae) and its Possible Relationship with Migration Polymorphism
Authors: Pavlov D. S. , Kostin V. V. , Ruch’ev M. A.
Published: April 2024

Individual concentrations of dopamine, norepinephrine, epinephrine, free triiodothyronine, total protein, albumin, as well as alanine aminotransferase activity were measured in embryos and larvae of the Atlantic salmon Salmo salar. Two groups of embryos and larvae differed by biochemical parameters were revealed. The relationship between biochemical differentiation and migratory polymorphism in the Atlantic salmon during the period of primary juvenile dispersal is discussed.
Qualitative Assessment of Status of Fishery Stocks of Black-Spined Herring Alosa kessleri kessleri Alosidae in Volga River Delta with LBI Method
Authors: Safaraliev I. A. , Voinova T. V. , Lepilina I. N.
Published: April 2024

The outcomes of qualitative assessment of the status of fishery stocks of the black-spined herring Alosa kessleri kessleri in the Volga River Delta have been reported. The data on the size composition of catches of the black-spined herring who migrated to the Volga River Delta to spawn in species peak fishing seasons in 1990–2000 and the latest data for 2016–2021, when the low biological values after the period of rapid decline in the stock size in the early 2000s, are used. The length-based indicator method assigned to the methods applied to assess data-poor fish stocks was used to determine indicators for the black-spined herring status in 1990–2000 and 2016–2021. This method allowed us to assess the qualitative status of stocks and the impact of fishery on them in the study periods. The outcomes may be used in recommеndations for black-spined herring fishery regulation.
Preliminary Data Indicate a Wider Distribution of the Little-Known Karakul Stone Loach Triplophysa lacusnigri (Nemacheilidae) in the Inland Waters of Tajikistan
Authors: Vasil’eva E. D. , Nazarov R. A.
Published: April 2024

Stone loaches collected in a stream associated with the Lake Bulunkul, Murgab district of the Gorno-Badakhshan Autonomous Region of Tajikistan, Pamir, are identified as Triplophysa lacusnigri, a species described and recorded only from the Karakul Lake system. These data indicate a wider distribution of the species in the Pamir. However, to determine the biodiversity of Pamir fish, molecular genetic studies of Triplophysa species are needed.
New Morphological and Molecular Data on the Southern Ninespine Stickleback, Pungitius platygaster (Gasterosteidae) from Southern Caspian Sea Basin
Authors: Esmaeili H. R. , Sayyadzadeh G. , Abbasi K.
Published: April 2024

Being a group of popular model organisms in eco-evolutionary biology, genetic, and genomic research studies, the genus Pungitius with 12 species is the most species-rich genus in the stickleback family Gasterosteidae including the Caspian nine-spine stickleback, Pungitius platygaster (Kessler, 1859), the only known species from southern Caspian Sea basin. Here, the new data based on morphological and molecular characters of the mtDNA COI barcode region, and current distribution range of P. platygaster is presented. These data confirm the validity of P. platygaster among its congeners, being sister clade to P. hellenicus from Greece. Morphologically, it is distinguished from the other congeneric species by complete pelvic girdle, 8−11 dorsal spines, and presence of large lateral scutes. The Caspian nine-spine stickleback is found in several closely placed freshwater and brackish waterbodies in the southern Caspian Sea.
Prospects for the Use of Metal Cations for the Development of Antimicrobial Complexes
Authors: Kadomtseva A. V. , Mochalov G. M. , Zhdanovich I. V. , Piskunova M. S.
Published: April 2024

It is known that antibacterial drugs with prolonged use cause antibiotic resistance in bacteria. Fast formation of resistance of microorganisms to modern antibacterial drugs requires the search for new methods of treatment. An alternative direction is the use of metal nanoparticles and their oxides as a basis for the creation of antimicrobial agents of a new generation, therefore, the study of methods for the synthesis of metal nanoparticles, their physico-chemical and pharmacological properties seems promising. The review examines the mechanisms of antibiotic resistance formation in biofilm and possible ways to overcome them for nanoscale metal particles, describes the synthesis and mechanism of action of nanoparticles containing silver, copper and zinc cations, presents the results of studies evaluating the effect of metal nanoparticles on antibiotic sensitivity in gram-positive and gram-negative bacteria, as well as fungi in comparison with the action of known dosage forms. Cu2+ and Zn2+ cations have a pronounced antibacterial effect in cultures Staphylococcus aureus and Pseudomonas aeruginosa. Ag+ cations showed the greatest efficacy against S. aureus, Escherichia coli, Klebsiella pneumoniae and Candida albicans.
Experimental Assessment of 3-meta-Pyridine-1,2,4-Oxadiazole Deoxycholic Acid Derivative as a Prototype of 5-α-Reductase Inhibitors in silico and in vivo Models
Authors: Meshkova Yu. V. , Baev D. S. , Sorokina I. V. , Popadyuk I. I. , Salomatina O. V. , Zhukova N. A. , Tolstikova T. G. , Salakhutdinov N. F.
Published: April 2024

5-α-Reductase (5-AR) inhibitors are considered the most effective drugs in the treatment of proliferative processes in prostate adenoma. These include two synthetic azasteroids – finasteride and dutasteride, which cause side effects in conditions of long-term course therapy which form the disorders of sexual function in men. We propose 3-meta-pyridine-1,2,4-oxadiazole derivative of deoxycholic acid as prototype of low-toxic 5-AR inhibitors. It has been shown that the new agent is able to penetrate the 5-AR binding site through the formation of covalent adducts with NADP-H, like finasteride. At the same time, both ligands have comparable with the target binding energy values (–20 and –15 kcal/mol, respectively, for finasteride and target compound). In experiments on testosterone and sulpiride models of BPH, we have found that intragastric administration of DCA derivative at a dose of 20 mg/kg and finasteride at a dose of 10 mg/kg has a similar prostatoprotective effect by reducing proliferative processes in the glandular epithelium and prostate stroma of rats. The new agent is less toxic than finasteride: the LD50 value in mice is 1500 mg/kg versus 1060 mg/kg in finasteride. Based on the results obtained, the 3-meta-pyridine-1,2,4-oxadiazole derivative of deoxycholic acid can be considered as a promising candidate for preclinical testing.
Hybrid Organomineral Carriers for Therapeutic Proteins
Authors: Zelenikhin P. V. , Galeeva A. G. , Islamova R. R. , Lopatin O. N. , Yarullin R. S. , Ilinskaya O. N.
Published: April 2024

Drug delivery systems are designed to provide the necessary concentration and prolonged effect of the active substance in the body. Orally administered protein preparations require protection from proteolysis in the gastrointestinal tract. Biocompatible hydrophilic polysaccharides in the matrix are especially promising, since they do not irritate the intestines and are gradually cleaved by specific glycosidases, releasing the therapeutic agent. The introduction of an insoluble porous mineral matrix into composition of carrier makes it possible to increase the concentration of therapeutic in matrix without a significant increase in the volume of drug tablet form. In this work, a new original organic mineral carrier based on heat-treated crushed clinoptiolite zeolite in combination with natural polysaccharides from red seaweeds – agar-agar, agarose, and carrageenan was created. Granular and finely dispersed clinoptiolites in the matrix are loaded with a promising therapeutic agent, Bacillus pumilus ribonuclease (binase), which exhibits selective cytotoxicity to tumor cells. It has been established that both granular and finely dispersed zeolites in combination with polysaccharides retain protein better than pure zeolites and provide a gradual complete release of enzyme in 18 hours. At the same time, the enzyme retains its catalytic activity and induces apoptosis up to 23.8% cells of the human duodenal adenocarcinoma HuTu80. The data obtained substantiate the prospects of dosage forms based on the used organomineral carriers designing.
Dynamics of Storage Lipids during the Recovery of Partially Bleached Coral Sinularia heterospiculata
Authors: Sikorskaya T. V. , Solodiy D. D. , Maskin E. V.
Published: April 2024

Global warming is causing the loss of coral symbionts and their bleaching. Researches of coral recovery are very important for the conservation of coral reefs. The lipidomic approach can provide detailed information about the processes that take place in the coral during bleaching and recovery. Using supercritical fluid chromatography in combination with mass-spectrometry, the dynamics of the main classes of storage lipids triacylglycerols (TG) and monoalkyldiacylglycerols (MADAG) during the recovery of the octocoral Sinularia heterospiculata after heat stress (32°C). It was shown that MADAG plays an important role in the energy balance of S. heterospiculata after heat stress. Under stress, the coral S. heterospiculata primarily consumed saturated MADAG molecular species. Changes in the profile of TG molecular species occurred only on the 16th day of the experiment. Probable, the stressed octocoral S. heterospiculata changes its energy strategy during recovery; therefore, the qualitative composition of reserve lipids is rearranged during the recovery period.
A New Complex of the Glucose Phosphate Isomerase Ribozyme with the Enzyme Hexokinase in Yeast
Authors: Solovjeva O. N.
Published: April 2024

The existence of a previously unknown ribozyme with the catalytic function of glucose phosphate isomerase was shown. It catalyzes the interconversion of glucose 6-phosphate and fructose 6-phosphate. This ribozyme was found in baker’s yeast Saccharomyces cerevisiae and was isolated as a complex with the enzyme hexokinase. The complex was easily isolated on an immunoaffinity column with antibodies to hexokinase. The ribozyme consists of 41–42 nucleotides and has a molecular weight of about 14.15–14.5 kDa. Km and Vmax are accordingly 0.14 ± 0.02 mM and 14.0 ± 1.3 U/mg for glucose 6-phosphate and 0.2 ± 0.03 mM and 15.4 ± 1.4 U/mg for fructose 6-phosphate. These kinetic characteristics are approximately the same in the complex and for the free ribozyme. Hexokinase within the complex retains its catalytic activity.
Radiopharmaceuticals for Oncology, Nonspecific to Glucose (PET and SPECT)
Authors: Belitskaya E. D. , Dimitreva V. A. , Kozlov A. N. , Oleinikov V. A. , Zalygyn A. V.
Published: April 2024

To date, the most common drug for the diagnosis of cancer tumors is [18F]-fluorodeoxyglucose, an radiopharmaceuticals for positron emission tomography diagnostics using the fact of increased glucose metabolism by cancer cells. At the same time, there are a number of cases where an approach based on glucose derivatives is not applicable. In many cases, inflammation or other benign processes are indistinguishable from tumor formations. For such cases of non-specificity of oncologies to glucose (not only tumor cells, but also healthy cells actively consume [18F]-fluorodeoxyglucose), the use of other metabolic pathways is required, which, in the case of a specific tumor in this organ, will be specific to the radiopharmaceuticals used.
TB-ISATEST: a Diagnostic LAMP Assay for Differentiation of Mycobacterium tuberculosis
Authors: Shirshikov F. V. , Bespyatykh J. A.
Published: April 2024

Consumption, white plague, tuberculosis… Only relatively recently, this disease has ceased to be an absolutely death sentence for infected people, but problems of the spread and diagnosis of the disease are still relevant. This paper presents results of the development of a new loop isothermal amplification (LAMP) assay, named TB-ISATEST, which targeting the species-specific gene rv2341 for the differentiation of Mycobacterium tuberculosis from non-tuberculosis mycobacteria. The assay is applicable for quantitative analysis of genomic DNA and allows detecting tenfold difference in concentration. The results of amplification optimization using a unique two-stage protocol based on the method of orthogonal Taguchi matrices are presented for the first time. A theoretical interpretation of the high amplification efficiency values observed in the LAMP reaction is proposed. Limit of detection of the developed assay is 40 copies of genomic DNA per reaction and amplification requires 15 min. In terms of the combination of characteristics, the TB-ISATEST assay surpasses all the known ways for identifying M. tuberculosis by the LAMP method.
Immunological Indicators of Pink Salmon Oncorhynchus during the Marine Phase of their Life Cycles
Authors: Gordeev I. I. , Mikryakov D. V. , Suvorova T. A. , Kuzmicheva S. V. , German A. V.
Published: April 2024

A comparative study of some parameters of nonspecific immunity in sexually mature individuals of pink salmon and chum salmon caught on June 6–July 1, 2018 by an epipelagic trawl in the open waters of the northwestern part of the Pacific Ocean was carried out. The level of antimicrobial properties of blood serum and nonspecific immune complexes in the tissues of the kidney, spleen and liver and the proportion of immunodeficient individuals were studied. Significant differences in the antimicrobial properties of blood serum and immunodeficient individuals were found. These differences are probably due to species characteristics, as well as the pre-spawning period of the annual cycle in pink salmon.
The Phenomenon of the Glycocalyx Layer Loss in the Acanthocephalan Corynosoma strumosum (Rudolphi, 1802) Lühe, 1904 (Acanthocephala: Polymorphidae) in Paratenic Hosts in Nature and in Experiment
Authors: Skorobrekhova E. M. , Nikishin V. P.
Published: April 2024

The phenomenon of renewal of the surface of the tegument in the acanthocephalan Corynosoma strumosum, which parasitizes paratenic hosts of different species, has been discovered and confirmed for the first time by electron microscopy. Under conditions of experimental invasion of Middendorffʼs eelpout Hadropareia middendorffii (Schmidt, 1904) (Zoarcidae), the separation of the glycocalyx from the tegument was observed on the 3rd day of the experiment. In acanthocephalans found in fish, dissected on the 14th and subsequent days of the experiment, and in fish infected in nature, the tegument was covered with the same thick layer of glycocalyx, formed apparently anew. A similar phenomenon was observed in two individuals of Corynosoma strumosum that invaded the halibut Hippoglossus stenolepis (Schmidt, 1904) (Pleuronectidae) in nature, however, their tegument lost the outer membrane along with a thick layer of glycocalyx. In other acanthoce-phalans that invaded this species of halibut, the tegument was covered with a thin layer of glycocalyx. It is assumed that the described phenomena are a morphological manifestation of the parasite’s defense against the host’s immune response.
Comparative Phylogeographic Analysis of Mitochondrial DNA Variability in Four Fish Species (Salmonidae and Cyprinidae) in the Northwest Pacific
Authors: Brykov Vl. A. , Malyar V. V.
Published: April 2024

The genetic variability of the mitochondrial genes COI and cytb was studied in specimens of the big-scaled redfin Tribolodon hakonensis (Günther, 1877) and the small-scaled redfin Tribolodon brandtii (Dybowski, 1872) collected off the coast of Sakhalin Island and the mainland coast of the Sea of Japan. The fragments of the mitochondrial genomes of these taxa are compared to data obtained for the Sakhalin taimen Parahuсho perryi (Brevoort, 1856) and chum salmon Oncorhynchus keta (Walbaum, 1792) from similar habitats. A comparative analysis of intraspecific mtDNA indicate that the formation of mtDNA lineages in four species of fish are associated with paleoclimatic changes in the northwestern Pacific region during the Pleistocene and are largely synchronous. In many instances, the calculated time of divergent evolution of mtDNA genealogical lineages coincide, which suggests the influence of similar evolutionary factors on the studied species.
Comparative Morphometric Analysis of the Azov Anchovy (Engraulis encrasicolus maeoticus Pusanov, 1926) and the Black Sea Anchovy (E. encrasicolus ponticus Alexandrov, 1927) Based on the Body Shape
Authors: Chesalin M. V. , Nikolsky V. N.
Published: April 2024

A comparative analysis of body shape was performed on 841 specimens of anchovy collected from 21 catches from the Sea of Azov, the Kerch Strait, and the Black Sea off the Crimea and the northeastern coast of the Caucasus in 2006–2007 and 2016–2017. Twenty-three measurements between 12 homologous landmarks of the body of each specimen according to the “Truss Network System” served as characters for analysis. Fifteen characters showed significant differences between the Azov anchovy Engraulis encrasicolus maeoticus Pusa-nov, 1926 and the Black Sea anchovy E. encrasicolus ponticus Alexandrov, 1927. Specimens of the Azov subspecies had larger relative values for all characters of the head region, the height of the trunk region, the re-lative length of the bases of the dorsal and anal fins, and the height of the base of the caudal fin. Specimens of the Black Sea subspecies had a greater postdorsal length and a larger distance from the end of the dorsal fin base to the end of the anal fin base. A multivariate principal component analysis revealed the highest variabi-lity of characters of body height, which depends on the fatness of the fish and demonstrates seasonal dyna-mics. The second group combines characters that do not have a seasonal component (dimensions of the head region, lengths of the bases of the dorsal and anal fins, and postdorsal distance) and can be used for distinguishing the shape of the Azov and Black Sea anchovies. The success rate of classification of Azov and Black Sea anchovies according to the body shape measurement characters using the discriminant analysis was 83.4%.
Assessment of Microplastic Degradation in Bottom Sediments Using Raman Microspectroscopy and Atomic Force Microscopy
Authors: Karpenko A. A. , Odintsov V. S.
Published: April 2024

The assessed degradation of microplastics from bottom sediments of the Laptev Sea, the Weddell Sea, the Chukchi Sea and Peter the Great Bay, Sea of Japan, was studied using Raman microspectroscopy and atomic force microscopy (AFM). The degree of amorphous-crystallinity of polyethylene terephthalate (PET) was determined by the ratio of Raman mode intensities (I1095 cm–1 / I1115 cm–1). Changes in the topography and mechanical properties of the surface of polymer fragments were studied by AFM methods. It has been shown that the degradation of PET found in the bottom sediments of the Laptev Sea affects mainly its crystalline phase. The amorphous phase of PET is affected to a much lesser extent or not at all. The same changes in the phase composition of the PET surface have been shown after plastic exposure in a marine aquarium in silty sand from the Amur Bay (Peter the Great Bay, Sea of Japan). AFM data show an increase in PET surface roughness and a decrease in elasticу modulus (Young’s modulus) in bottom sediment samples. Raman microspectroscopy also shows signs of degradation of cellophane fragments from the Weddell Sea, polyvinyl chloride (PVC) from the Laptev Sea, and polyethylene (PE) from the Amur Bay.
Marine Labyrinthulomycetes
Authors: Pereboev D. D. , Bubnova E. N.
Published: April 2024

Labyrinthulomycetes are a small but very important group of marine fungi-like organisms. Labyrinthulomycetes are ubiquitous, can be associated with living plants, algae, and animals and can decompose a variety of organic remains. These organisms are able to synthesize and abundantly accumulate lipids, in particular, polyunsaturated fatty acids, some of which are of great interest for biotechnology. The scientific information about labyrinthulomycetes is currently accumulating very quickly. Our study is devoted to reviewing presently available data on the structure, biology and taxonomy of these organisms. The review examines the problems of methodological approaches to the study of these organisms, as well as the diversity, distribution and significance of Labyrinthulomycetes in marine ecosystems.
Domoic Acid in Cultures of the Diatom Genus Pseudo-nitzschia H. Peragallo in H. Peragallo & M. Peragallo, 1900 and in Bivalve Samples from the Russian Waters of the Sea of Japan and the Pacific Waters of Kamchatka
Authors: Stonik I. V. , Popov R. S. , Tsurpalo A. P. , Dmitrenok P. S. , Shchelkanov M. Yu. , Orlova T. Yu.
Published: April 2024

Content of a dangerous amnesic toxin – domoic acid (DA) – was determined in cultures of the diatom genus Pseudo-nitzschia and in bivalve samples collected in the Russian waters of the Sea of Japan and off the Pacific coast of Kamchatka. For the first time, the presence of DA has been confirmed in cultures of Pseudo-nitzschia pungens (Grunow ex Cleve) G.R. Hasle, 1993 and P. delicatissima (Cleve) Heiden, 1928 from the Pacific coast of Kamchatka with the use of the competitive enzyme-linked immuno-sorbent assay (cELISA). Relatively high concentrations of DA were recorded in the horse mussel Modiolus kurilensis F.R. Bernard, 1983 (2.92 mg/kg based on high-performance chromatography-mass spectrometry (HPLC-MS) and 2.8 mg/kg based on cELISA) and in the Gray mussel Crenomytilus grayanus (0.07 mg/kg based on HPLC-MS and 0.2 mg/kg based on cELISA) collected in the Sea of Japan. It has been shown that for assessing relatively low concentrations of amnesiotoxin (less than 5 ng/ml in microalgal cultures and less than 0.05 mg/kg in mollusks) cELISA assay is an alternative to HPLC that does not allow to detect DA in such samples.
The Structure of the Zooplankton Communities in Sukhoe More Bay, Southeastern White Sea
Authors: Sobko E. I. , Klimov S. I. , Neverova N. V. , Moreva O. Yu.
Published: April 2024

This paper presents the results of our investigation of the zooplankton communities from Sukhoe More Bay, located in the southeastern part of Dvina Bay of the White Sea, in July−August, 2018. The species composition, quantitative characteristics and spatial distribution of zooplankton were studied. The zooplankton communities are composed of 34 species of hydrobionts. Copepods were the dominant group in the entire study area. The zooplankton communities were characterized by high quantitative indicators. Juvenile stages of copepods were a significant contribution to the formation of the total number of zoocenoses. During high water level, the abundance of zooplankton was 37 000 ind./m3, biomass, 0.6 g/m3 (wet weight). During low water level these parameters were 210 000 ind./m3 and 1.7 g/m3 (wet weight), respectively. The structure, abundance and spatial distribution of zooplankton in the bay are determined by the morphometric features of the reservoir (shallow water), the influence of a complex of environmental factors (temperature and salinity), as well as tidal phenomena.
Prokaryotic Plankton and Viruses in the Waters of the Fram Strait in the Winter Period
Authors: Venger M. P. , Dvoretsky V. G. , Vashchenko A. V. , Ishkulova T. G. , Maksimovskaya T. M. , Vodopyanova V. V.
Published: April 2024

New data have been obtained on the distribution of prokaryotic plankton and pelagic viruses in the Fram Strait (the Greenland Sea) during the polar night (late November). Three main types of water masses were present in the study area: surface polar, Atlantic, and transformed Atlantic. The content of mineral biogenic elements increased with depth. The concentration of chlorophyll a had low values (0.07–0.13 mg/m3). The abundance and biomass of prokaryotes varied from 286 000 to 675 000 cells/mL and from 2.7 to 11.7 mg C/m3, respectively. The composition of prokaryotic plankton was dominated by single small cells (more than 97% of the abundance and more than 68% of the biomass). The average cell volume was 0.034–0.096 µm3. The number of viruses varied from 724 000 to 3 920 000 particles/mL, and the biomass varied from 0.040 to 0.216 μg C/m3. Against the background of local maxima in the abundance of prokaryotic plankton in the 0–25 m layer, the highest concentrations of viruses were noted in the surface layer. In the latitudinal distribution (from south to north), an increase in the number of viruses and prokaryotes was revealed. A close relationship between their abundance and biomass with hydrological parameters and phosphate content was established; the role of certain water masses in the vertical distribution of microbes was insignificant. The relatively high abundance of viruses and prokaryotes indicated their significant activity during the polar night.
Peculiarities of the Magnetic Field of Geothermal Systems of the Pauzhetsky Area (South Kamchatka)
Authors: Nuzhdaev I. A. , Rychagov S. N. , Feofilaktov S. O. , Denisov D. K.
Published: April 2024

Based on many years of research, maps of magnetic field anomalies ΔTa for large geothermal systems of the Pauzhetsky region of South Kamchatka were constructed. Magnetic fields have both general characteristics and individual features for each research object. In the area of Nizhne-Koshelevsky steam-dominated geothermal field identified a system of linear negative magnetic field anomalies, confined to thermal controlling discontinuous tectonic disturbances. Pauzhetsky geothermal field is characterized by a heterogeneous structure of the anomalous magnetic field ΔTa: NW region is marked by a quiet weakly negative magnetic field, indicating the predominance in this part of the field lateral spreading of hydrotherms from the upper aquifer; SE – a large number of alternating magnetic anomalies of high intensity, confined to subvolcanic bodies of acidic to moderate composition. The South Kambalnaya group of thermal fields is characterized by a lower magnetic induction modulus T as compared to the Pauzhetsky and Lower Koshelevsky geothermal fields, indicating a more intense alteration of the Kambalnaya Ridge rocks by hydrothermal-metasomatic processes, apparently as a result of long-term exposure to convective heat flow.
The History of Formation of Pliocen-Quaternary Valley Lava Rivers in the Northeast Part of the Javakheti Volcanic Highland (Lesser Caucasus)
Authors: Parfenov A. V. , Lebedev V. A. , Vashakidze G. T. , Yakushev A. I. , Ediberidze B. D.
Published: April 2024

The article presents new results of geological-stratigraphic and isotope-geochronological study of young lavas in the northeast part of the Javakheti Highland (Lesser Caucasus, Republic of Georgia). A valley lava river (Algeti flow) with a complex structure and total length about 55 km was described for the first time (no information about this valley lava river was previously published in the scientific literature). It was shown that a young magmatism in the northeast of the Javakheti area developed in the time interval of 3.2–1.5 Ma. Its early phase (3.19 ± 0.10 Ma) was marked by the formation of the longest (up to 100 km) valley lava river (Khrami flow), composed of basalts, among the similar geological objects known in the Lesser Caucasus. Subsequently (2.7–2.5 Ma), the continuation of eruptions led to the formation of extensive lava plateaus in the region (Tsalka, Gomareti and others). The formation of the Algeti valley lava river (Algeti flow), composed of basaltoids, began from the end of Piacenzian and continued over ~1 m.y. until the beginning of Gelasian (2.7–2.0 Ma) as a result of the activity of volcanoes in the northern part of the Javakheti Range. The final stage of formation (1.9–1.5 Ma) of Algeti flow was likely associated with eruptions of volcanic cones near Tabatskuri Lake. The obtained data, along with the reconstruction of the history of young magmatism, made it possible to follow the main features in the formation of modern relief and the river valley system in the considered part of the Lesser Caucasus.
Three-Dimensional Numerical Modeling of Lava Dynamics Using the Smoothed Particle Hydrodynamics Method
Authors: Starodubtsev I. S. , Starodubtseva Y. V. , Tsepelev I. А. , Ismail-Zadeh A. T.
Published: April 2024

Lava domes and lava flows are major manifestations of effusive volcanic eruptions. Less viscous lava tends to flow long distances, depending on the volcanic slope topography, the eruption rate, and the viscosity of the erupted magma. When magma is highly viscous, its eruption to the surface leads to the formation of lava domes and their growth. The meshless smoothed particle hydrodynamics (SPH) method is used in this paper to simulate lava dynamics. We describe the SPH method and present a numerical algorithm to compute lava dynamics models. The numerical method is verified by solving a model of cylindrical dam-break fluid flow, and the modelled results are compared to the analytical solution of the axisymmetric thin-layer viscous current problem. The SPH method is applied to study three models of lava advancement along the volcanic slope, when the lava viscosity is constant, depends on time and on the volume fraction of crystals in the lava. Simulation results show characteristic features of lava flows, such as lava channel and tube formation, and lava domes, such as the formation of a highly viscous carapace versus a less viscous dome core. Finally, the simulation results and their dependence on a particle size in the SPH method are discussed.
Mechanisms of Translation of Deep-Seated Pulses into External Shells of the Modern Earth: Evidence from Late Cenozoic Global Tectonomagmatic Activation of Our Planet
Authors: Sharkov E. V. , Bogina M. M. , Chistyakov A. V.
Published: April 2024

It is known that the Earth’s history is characterized by periodic activation of tectonomagmatic processes, when they are intensified without visible reasons. This is obviously related to the evolution of deep-seated petrological processes, the peculiar reflect of which are events in the external shells of the modern Earth (tectonosphere), but the nature of these processes and mechanisms of their translation in tectonosphere remain weakly studied. This problem is considered by the Late Cenozoic (Neogene–Quaternary) global activation. The modern Earth represents a cooling body with solidifying liquid iron core. This process should be accompanied by several thermodynamic, physical, and physical-chemical effects, which could lead to the internal activation of our planet. We attempted to decipher these problems using available geological, petrological, geochemical, and geophysical data on the present-day activation. It is shown that main active element in the modern Earth is uninterruptedly upward moving thin crystallization zone located between completely solidified part of the core (solid inner core) and its completely liquid part (external liquid core). Diverse phase transitions in a cooling melt passing through bifurcation points are related to this zone. The phase transitions are represented by both a change of crystallizing solid phases which built up inner core and retrograde boiling with formation of drops of “core” fluids. These drops are floated in high-Fe host melt and are accumulated at the mantle base, where they are involved in the formation of mantle plumes, which are the main carriers of deep-seated pulsed into external geosphere, and finally leave the core with them. It is suggested that in one of such points the fluid solubility in cooling high-Fe liquid of external core sharply decreases. This should lead to the simultaneous intensification of retrograde boiling of this melt over the entire zone surface of zone of the core crystallization zone, i.e., on a global scale. This could provide the influx of excess “core” fluids required for large-scale generation of mantle plumes and serve as trigger for Late Cenozoic global tectonomagmatic activation of the Earth.
Isotopic Composition for Helium in Late Cenozoic South-Baikal and South-Khangai Volcanic Areas
Authors: Rychkova K. M. , Kalnaya O. I.
Published: April 2024

The paper considers isotopic composition of helium (3Не/4Не = R) in groundwater of South-Baikal (SBVA) and South-Khangai volcanic areas (SKhVA) during the Late Cenozoic period. The differences in the behavior and magnitude of the parameters were established. It is found that the mentioned differences in 3Не/4Не concentrations within South-Baikal and South-Khangai volcanic areas correspond to mantle reservoirs with different helium isotope compositions. This confirms that the Late Cenozoic volcanism of South-Baikal and South-Khangai volcanic area is controlled by mantle sources related to mantle plumes of the Central-Asian hot mantle field.
Gold-Silver Epithermal Deposit the Lower Birkachan (Omolonsky Massif, North-East of Russia): Geological Structure, Ore Mineralogy, Age
Authors: Glukhov A. N. , Priymenko V. V. , Kotov A. B. , Fomina M. I. , Salnikova E. B. , Mikhalitsyna T. I. , Polzunenkov G. O.
Published: April 2024

Described of structure, mineralogy and age of ore and hosted rocks of the recently explored Nizhniy Birkachan Au-Ag epithermal deposit. The orebodies is a quartz-carbonate-adularia veins and veining zones, that hosted porphyry granodiorites with U-Pb age (ID-TIMS) 335 ± 2 Ma. The ore contain low sulfides, low Ag grades. Main ore minerals – pyrite. Silver minerals represented by tennantite-tetraedrite, Ag sulfide, native Au and Ag, gessite, The 40Ar/39Ar age of adularia from vein 169 ± 4 Ma. This young age we explain by rejuvenation of isotope system after intrusion of non-mineralizied Jurassic mafic dykes. The main features of Nizhniy Birkachan Au-Ag epithermal deposit similar with other Au-Ag deposits of Kedon magmatic belt of the Omolon massif. All that was formed in 290–335 Ma age interval.