bluuebunny/crossref_metadata_2025 huggingface dataset:
GEODATA OF THE MOSCOW UNIVERSITY HERBARIUM: DATA STRUCTURE AND GEOREFERENCING METHODICS
Authors: Seregin A. P. , Pashkina V. N. , Pospelov I. N.
Published: April 2024

Digitisation of the Moscow University Herbarium (MW) was started in the spring of 2015. Since October 2016, we have been publishing the images of specimens on the portal of the Moscow Digital Herbarium (https://plant.depo.msu.ru/) in open access mode. Gradually, we started to publish extended metadata on our portal, like full transcriptions of labels and georeferences, i.e. the coordinates of collection sites for each specimen. As of January, 14, 2023, two thirds of the specimens of the Moscow University Herbarium (693168 specimens, or 66%) are georeferenced, while 359593 specimens are still in work. The article describes the geodata of the Moscow University Herbarium both in the geographical aspect (data coverage for different regions) and in the aspect of georeferencing accuracy. General guidelines for georeferencing herbarium collections are given.
DIATOMS IN ALGOCENOSES OF PISANETS LAKE (REPUBLIC OF KARELIA)
Authors: Genkal S. I. , Komulaynen S. F.
Published: April 2024

The scanning electron microscopy study of phytoplankton, phytoperiphyton and microphytobenthos has revealed 208 taxa of Bacillariophyta of specific and intraspecific ranks in Pizanets Lake. Among them, 66 species and varieties are new to the flora of Karelia, including 8 ones new to the flora of Russia. Some algae (13) are identified only to the genus. An ecological assessment of the species composition in relation to the characteristics of the environment is carried out.
CHAROPHYTES (CHARALES, CHARACEAE) OF THE REPUBLIC OF BASHKORTOSTAN (SOUTH URAL)
Authors: Romanov R. E. , Abdullin Sh. R.
Published: April 2024

Eleven species of charophytes from three genera, Chara, Nitella and Nitellopsis, were found in the Republic Bashkortostan according to herbarium collections and field studies covering the years 1915–2016, among them one newly recorded genus Nitellopsis and four new records of species, namely Chara contraria, C. papillosa, C. subspinosa, and Nitella obtusa. These data allowed re-assessment of few records known from published sources. Biotope and ecoregion preferences of the species were outlined. Most species have been known from the region of study for a long time. Hard water lakes and, especially, water bodies of rich minerotrophic fens are most important regional habitats of charophytes. Some populations of stenobiont species seem to be stable despite significant human transformation of Bashkortostan natural environment. A tentative Red List of charophytes of the Republic of Bashkortostan was suggested.
NEW FINDS OF RARE SPECIES IN THE UNYA RIVER BASIN (NORTHERN URALS)
Authors: Teteryuk L. V. , Dulin M. V.
Published: April 2024

The article presents data on the discovery of two rare species in the Unya River basin (Northern Urals), on the territory of the complex reserve “Uninsky”. Since 1994, it has been part of the UNESCO World Natural Heritage Site “Virgin Komi Forests”. As a result of research in 2022, the taxon Astragalus karelinianus, new for the Northern Urals, was identified. And the presence of Alyssum lenense Adams in the flora of the European Northeast of Russia was confirmed. Relict locations of both taxa on the rocks of the Unya River are the northernmost in the Urals.
BIOMETRIC INDICES OF POLLEN FROM NATURAL POPULATIONS OF PINUS BRUTIA VAR. PITYUSA (PINACEAE) OF THE CRIMEAN MOUNTAINS
Authors: Koba V. P. , Korenkova O. O. , Makarov N. A.
Published: April 2024

The study of biometric characteristics of Pinus brutia var. pityusa pollen was carried out in natural populations of P. brutia var. pityusa in the Crimean Mountains. The pollen was collected during the period of its free flight on sample plots along four hypsometric profiles. In the western part of the southern macroslope of the Main Ridge of the Crimean Mountains on Cape Aya in the Ayazma tract, 3 sample plots were laid at altitudes of 50–290 m above sea level, in Batiliman – 2 plots, at altitudes of 50 and 120 m above sea level; in the eastern part of the macroslope, 3 plots were laid on Karaul-Oba Mt. at altitudes of  40–120 m above sea level, and in the Novyy Svet tract – 2 plots at 50 and 100 m above sea level. Biometric analysis of pollen grains was carried out on temporary acetocarmine slides using generally accepted methods. The results of the study showed that an average size of the pollen grain of P. brutia var. pityusa in natural populations of the Crimean Mountains varies within the following ranges: total grain length from 81.5 to 88.5 μm, the length and height of the pollen grain body 52.2–59.4 μm and 47.8–53.4 μm, respectively, and the length and height of the air sac 40.0–43.0 μm and 25.5–30.4 μm, respectively. The smallest pollen is formed in coastal stands. In the plantations of P. brutia var. pityusa in the western part of the Crimean Mountains, a decrease in the length and height of the air sacs was noted. It was revealed that the indices characterizing the ratio of individual structural elements of the pollen grain, namely γ – the ratio of the body length to the height of the air sac of the pollen grain, δ – the ratio of the body height to the height of the air sac, and Θ – the ratio of the body length to the length of the air sac, allow to analyze aerodynamic properties of P. brutia var. pityusa pollen. The decrease in γ, δ, and Θ pollen indices in the plantations of Ayazma and Batiliman reflects a decrease in the efficiency of its aerial distribution, which has a negative effect on the level of heterogeneity of natural populations in these territories.
PLASMODESMATA OF BROWN ALGAE (PHAEOPHYCEAE): STRUCTURE, LOCALIZATION AND FUNCTIONS
Authors: Kudryavtseva E. O.
Published: April 2024

The present review outlines the history of the study of plasmodesmata in brown algae, describes their ultrastructure, which differs from that of other groups of algae and land plants, presents variants of localization of plasmodesmata in different members of Phaeophyceae – from a scattered location to arrangement into pit fields; the functions performed by plasmodesmata in the thalli of brown algae are listed. Possible prospects for further study of these structures are specified.
CLASSIFICATION OF DWARF PINE COMMUNITIES IN THE NORTH OF THE KORYAK DISTRICT (KAMCHATKA TERRITORY)
Authors: Neshataeva V. Yu. , Neshataev V. Yu. , Skvortsov K. I. , Kuzmina E. Yu. , Korablev A. P.
Published: April 2024

A detailed geobotanical characteristic of Siberian dwarf-pine (Pinus pumila (Pall.) Regel) communities of the north of the Koryak District is presented. The vegetation classification based on 83 relevés has been elaborated using main principles and classification methods of Russian dominant-determinant approach. As the result 10 associations, 10 subassociations and 9 variants classified within 5 association groups were revealed. The peculiarities of their species composition, community structure, ecology and geographical distribution were characterized. Using soil characteristics, several types of sites were recognized. It was shown that mesophytic moss-rich dwarf-pine shrubs (Pinetum pumilae hylocomiosum) were closely connected to the mean values of soil moisture and soil fertility of the sites. Rhododendron-rich dwarf-pine communities (subass. Pinetum pumilae rhododendroso aurei–hylocomiosum) adjoined them but they usually occurred on higher altitudes. Lichen-rich dwarf-pine shrubs (Pinetum pumilae fruticuloso–cladinosum) occupied the driest and poorest sites at the upper border of dwarf-shrub altitudinal belt (350–400 m a.s.l.). The dwarf-shrub-rich Siberian dwarf-pine communities (ass. group Pineta pumilae fruticulosa) were closely connected to rather dry and poor sites. In wet sites with shallow groundwater, Sphagnum-rich dwarf-pine communities (Pinetum pumilae sphagnosum girgensohnii) were found. Cloudberry-rich dwarf-pine shrubs (subass. Pinetum pumilae chamaemori–rubosum) adjoined them but mainly occurred on the peat hillock of palsas. The variation in the species composition and structure of communities are determined by their position in the relief and the density of the dwarf-pine layer. With a similar density of dwarf-pine, Sphagnum-rich dwarf-pine communities form in the foothills, and lichen-rich dwarf-pine shrubs form in mountains. The species diversity and the abundance of the subordinate layers are significantly reduced at the maximum density of the dwarf-pine; so poor-herb dwarf-pine communities (Pineta pumilae oligoherbosa) are formed.
GYNODIOECY IN GERANIUM PSEUDOSIBIRICUM (GERANIACEAE)
Authors: Gordeeva N. I. , Komarevceva E. K.
Published: April 2024

A breeding system of the gynodioecious Geranium pseudosibiricum J. Mayer in three meadow and meadow-steppe communities of the Altai Mountains was investigated. Statistically significant differences in the morphology of flowers between hermaphrodite and female plants have been established (p 0.001). The stamens of pistillate flowers in females are reduced and do not produce pollen. Statistically significant differences between the sexes in seed productivity have been established: female plants form several times more fruits than hermaphrodite ones (p 0.01); a high female compensation was detected for G. pseudosibiricum. Infertile hermaphrodite plants were found in the coenopopulations. Female palnts in the coenopopulation CP1 constitute 55% of the total number of generative plants. In natural habitats, G. pseudosibiricum is characterized by good seed breeding and successful formation of offspring, which contributes to the maintenance of female plants in the coenopopulations of the species. The features of breeding system of  G. pseudosibiricum have revealed significant differences between female and hermaphrodite plants.
EFFECT OF THE PERISTOMATAL RIM UPON STOMATAL MOVEMENTS IN POPULUS MEXICANA (SALICACEAE)
Authors: Pautov A. A. , Bauer S. M. , Ivanova O. V. , Krylova E. G. , Sapach Yu. O. , Ivanova A. N. , Yakovleva O. V. , Truchmanova G. R. , Pautova I. A.
Published: April 2024

Light and scanning electron microscopy were used to study the stomatal complexes of Populus mexicana, which has xeromorphic leaf structure. In this poplar, the stomatal complexes are laterocytic and paracytic. The subsidiary cell walls form the peristomatal rim, which rests upon the outer tangential walls of the guard cells. To elucidate the function of the peristomatal rim, we applied modelling using the finite element method. The modelling has shown that the inner and the outer tangential walls of the guard cells bend outward when the stoma is opening. The peristomatal rim hinders the movements of the outer tangential walls of the guard cells. Due to the peristomatal rim, the open stomatal pore sinks deeper into the epidermis. It is narrower and better covered with the outer stomatal ledges, than the one in the stomatal complex without peristomatal rim. The probability of influence of stomatal mechanics in P. mexicana upon water losses during transpiration is under discussion.
Taste Preferences of Cyprinid Fishes (Cyprinidae). A Comparative Study
Authors: Kasumyan A. O. , Isaeva O. M.
Published: April 2024

Palatability of various substances (amino acids, carboxylic acids, some organic acids, and basic taste substances) is presented for eight species of cyprinids (Cyprinidae): bream Abramis brama, European bitterling Rhodeus sericeus amarus, sunbleak Leucaspius delineatus, crucian carp Carassius carassius, common bleak Alburnus alburnus, dace Leuciscus leuciscus, chub L. cephalus, and tiger barb Puntigrus tetrazona. The taste sensitivity to certain substances has been estimated for these species. A comparative analysis has been performed considering the published data on other species of the family; as a result, a high specificity of the taste spectra of cyprinids is obtained. No obvious relationship of taste preferences with the fish lifestyle, their diet, and phylogenetic similarity has been revealed. All cyprinids keep food objects in their oral cavity the longer, the most is the food object palatability. The number of orosensory testing events performed with a food object differs in fish of different lifestyles and belonging to different trophic categories, but does not correlate with the taste properties of the food object. During orosensory testing, the first retention of the grasped object in the oral cavity is longer than subsequent ones. Retentions are many times longer if the object is finally swallowed than when the fish refuse to consume. The great similarity of behavior in cyprinids during orosensory testing of food indicates the conservatism of the feeding behavior compared to taste reception.
A Comparative Study of the Leukocyte Formula of the Peripheral Blood, Head Kidney and Spleen of the Bream Abramis brama (Cyprinidae) in the Middle Volga Reservoirs
Authors: Suvorova T. A. , German  A. V. , Mikryakov D. V.
Published: April 2024

A comparative study of the leukocyte formula of peripheral blood, the head section of the kidney and spleen of the bream Abramis brama, inhabiting the reservoirs of the Middle Volga (Kuibyshev, Cheboksary and Gorky), was carried out. In the studied fish, a predominance of lymphocytes and a low content of neutrophils were recorded in the peripheral blood and spleen. In the head kidney of the breams from the Kuibyshev Reservoir, a significantly high level of blast forms of cells and a low level of neutrophils were noted, and in individuals from the Gorky Reservoir, a low content of monocytes and the absence of eosinophils were noted compared to fish from other reservoirs.
Variable Eyes Degeneration of the Cave Carp Sinocyclocheilus bicornutus (Cyprinidae) from Guizhou Province, Southwest China
Authors: Wen H. , Wang Y. , Yang X. , Yan S. , Luo T. , He Y. , Zhou J.
Published: April 2024

Sinocyclocheilus bicornutus is a valid cave–dwelling cyprinid species with small eyes from Guizhou province, southwest China, the close relatives of which are also small eyed and obligate cave–dwelling. Our expeditions in 2015 to 2017 found the intraspecific variability of eye degeneration based on total 114 specimens collected from one lighted and two dark caves with an altitude of about 1350 m. Three morphotypes, the small eyed, the rudimentary eyed, and the eyeless, co-occurred in each cave. The eye size closely correlates with the standard length SL in the lighted cave, while the correlation of the eye size and SL become loosely related in the dark caves which associated with increased proportion of significantly degenerative eyed morphotypes. It implies that the developmental retardation occurs in the darkness and remains in adult stage. The variable eye-reduced populations of S. bicornutus provide an interesting model to address the involvement of potential epigenetic mechanisms with the regressive evolution of cavefish.
X-ray Microtomography Study of Cranium, Pectoral Fin and Girdle, and Weberian Apparatus Development in Juvenile Triplophysa stewarti (Nemacheilidae)
Authors: He Y. , He D. K.
Published: April 2024

The stone loach genus Triplophysa is a major component of the Tibetan Plateau ichthyofauna, and its taxonomy and phylogenetic relationships are far from resolved. Skeletogeny patterns contain useful phylogenetic signals, but developmental data for Triplophysa are scarce. Here, we present an X-ray microtomography study of the development of the cranium, pectoral fin and girdle, and Weberian apparatus of juvenile Triplophysa stewarti (12–55 mm standard length). We reveal that the smallest juveniles possess a fontanelle and well-developed Weberian ossicles. Furthermore, the development of the cranium, pectoral fin and girdle, and bony capsule of the Weberian apparatus is illustrated, such as the suturation of preethmoid I to prevomer, the reduction of pectoral radials from four to three by fusion of the most internal two. A paired bony capsule fully enclosing the anterior swim bladder room characterizes the Weberian apparatus of nemacheilid and balitorid loaches. Our data demonstrate that the anterior wall of the bony capsule originates from a vertical plate expanded from the descending process 2, which is a homologue to the “anterior plate” in the superfamily Cobitoidea sensu lato, with the exception of Cobitidae. The lateral process 2 separates from this anterior plate. The horizontal process 4 expands anteriorly to meet the anterior wall, and when posteriorly expanded and curved downward, finally fuses with the bottom wall to close the bony capsule. Accelerated or retarded development of the aforementioned skeletal structures will result in differentiated features in Triplophysa and related nemacheilid genera.
Distribution and Some Aspects of Biology of Hozukius guyotensis (Sebastidae) in the Area of the Emperor Seamount Chain
Authors: Kurbanov Yu. K. , Michalutin E. A.
Published: April 2024

Based on the materials collected in the course of longline fishing in the area of the Emperor Seamount Chain, new data on the occurrence, distribution, and some features of the biology and ecology of Hozukius guyotensis have been presented. It has been shown that it is a common species in the ichthyofauna of the studied area. It is observed on the peaks and in the slope area of the Nintoku, Lira, and Koko seamounts at depths of 385–1015 m; its largest catches are typical for the range of 500–700 m. In the catches, H. guyotensis was represented by individuals 32–73 cm long and weighing 0.45–5.27 kg. Presumably, the species begins to mature at a length of 44–46 cm; the main stage of its reproduction takes place in spring.
Fish Nutrition at the Underwater Mountains of the Whale Ridge (Southeastern Atlantic). 3. Structure of Fish Accumulations and Fish Feeding
Authors: Gushchin A. V.
Published: April 2024

Pelagic accumulations of fish are formed above the underwater mountains of the Whale Ridge in the evening and at night, but not observed during daylight hours. The study of such an accumulation above one of the mountains reveals its structure. The central part of the cluster consists of splendid alfonsino Beryx splendens, silver scabbardfish Lepidopus caudatus and oilfish Ruvettus pretiosus tend to keep on the periphery of the splendid alfonsino accumulation. Previously, it was found that food of splendid alfonsino, silver scabbardfish, rosefish Helicolenus mouchezi, Richardson’s boarfish Pentaceros richardsoni, and Cape bonnetmouth Emmelichthys nitidus consisted of organisms forming sound-scattering layers (SSL) above the underwater mountains. The composition of food and the daily dynamics of feeding of the listed commercial fish species indicate that they use two feeding tactics. In the first case, rosefish, Richardson’s boarfish, and Cape bonnetmouth forage for most of their food during the day at the bottom, when the SSL-forming organisms descend to the top of the underwater mountain during the diel migration. In the second case, splendid alfonsino, silver scabbardfish, and oilfish as part of a structured pelagic aggregation feed at night on the organisms rising into the upper layers of the water and forming sound-scattering layers. This tactic expands the possibilities for feeding fish that form pelagic aggregations in the dark hours of the day and allows the use of organisms both brought by the current to the mountain top and those that descended here earlier during the diel migration and then stayed until the beginning of the evening.
Gonadal and Germ Cells Morphology of Nuchequula gerreoides and Eubleekeria splendens (Leiognathidae) from the Pranburi River Estuary of Thailand
Authors: Kanjanarakha T. , Kettratad J. , Senarat S. , Jiraungkoorskul W. , Angsujinda K. , Kaneko G.
Published: April 2024

The decorated ponyfish Nuchequula gerreoides and splendid ponyfish Eubleekeria splendens are two abundant leiognathid species in the Pranburi River Estuary, Thailand. However, information about their reproductive activity is still limited, preventing the implementation of effective conservative management. In this study, we investigated the sex ratio and the reproductive characteristics in relation to the size distribution of these polyfish species. Fishes were collected during February to November in 2017. The male to female ratios in N. gerreoides and E. splendens were 1.00 : 5.65 (χ2 = 55.2) and 1.00 : 4.65 (χ2 = 40.0), respectively. These ponyfishes shared similar morphology and histology of the reproductive system. All females were classfied as a juvenile because only undeveloped stage (stage 0) oocytes were found in the ovary. Males below 3.4 cm were all juvenile, but all males above 3.4 cm were mature having spermatogenic cells at spermatogenic stages.
First Data on Ecology and Biology of Arctoraja sexoculata (Arhynchobatidae) from the Area off Kuril Islands
Authors: Kurbanov  Yu. K. , Vinogradskaya A. V.
Published: April 2024

First information on the Arctoraja sexoculata frequency of occurrence, ecology, and biology, from the area off the middle Kuril Islands has been provided. It is estimated that the Arctoraja sexoculata is a common bycatch species in trawl fishing for the commander squid Berryteuthis magister in this water area. The locations of catch events for this species were localized off the Ketoy and Simushir Islands and in the Diana Strait at the depths of 250–490 m at a water temperature near the bottom of 1.8–2.5°С. It is supposed that the species belongs to the mesobenthal ichthyocene. In the catches, A. sexoculata represented by individuals of 26–90 cm length and 0.1–5.6 kg body mass. The species probably reaches the age of maturity for the first time at 8–9 years old and over. Its highest life expectancy is 16 years. The individuals of 50–90 cm length become predators consuming predominantly cephalopods and fishes, in the same time isopods and ctenophores among the food items were rarely recorded.
New Data on the Age, Size and Feeding of the Shi Drum Umbrina cirrosa (Sciaenidae) off the Black Sea Coast of Crimea
Authors: Tamoikin I. Yu. , Kutsyn D. N. , Vdodovich I. V.
Published: April 2024

The shi drum Umbrina cirrosa is a rare poorly studied fish species in the Black Sea. The largest individual for this water area was recorded off the coast of the Crimea; a male, whose total length was 784 mm, standard length 706 mm, body weight 5515.2 g, age 4 years; gonads of the maturity stage III had a weight of 33.11 g. Mollusks Solen marginatus and Abra segmentum, polychaete of the family Scalibregmatidae, and the jaguar round crab Xantho poressa were found in the diet composition. The paper presents a morphological description of otoliths (sagittae). The information about the known cases of the shi drum capture in the Black and Azov seas is considered. It is revealed that the maximum size of individuals of the species in the Black Sea is higher than in the Mediterranean Sea; possible causes of geographical variability of the sizes are analyzed. It is shown that this species is one of the fastest growing fish in the Black Sea.
Morphology of the Buccal and Opercular Sealing Apparatus in Mudskippers (Gobiidae: Oxudercinae)
Authors: Tran L. X. , Nguyen T. T. K.
Published: April 2024

Although possession of the large bucco-opercular cavity and its utilization in the feeding, breathing, egg brooding, and burrowing activities are quite obvious in mudskippers, the apparatus of this structure is little known. In the present study, we examined the anatomy of the bucco-opercular sealing apparatus of four oxudercine gobies, Oxuderces nexipinnis, Scartelaos histophorus, Boleophthalmus boddarti, and Periophthalmodon septemradiatus, showing different degrees of terrestriality. The results show that the morphological modifications including the short and restricted gill openings, the membranes on the gill opercular edge (except O. nexipinnis), and the developed hyohyoideus 3 could serve to seal the gill openings. The possible movement of the ceratohyal, the relative height of the urohyal, and the developed geniohyoideus could function to seal the mouth. Contraction of the hyohyoideus 1 to 3 could compress the opercular cavity generating strong mud spitting, whereas activation of the dilator opercula, levator opercula, and a portion of the geniohyoideus may serve to expand this cavity enable sucking mouthful of water at slow speed. These morphological modifications are presumable to facilitate vital activities of mudskippers as transition onto land.
Reproductive Condition in the Caspian Anadromous Shad Alosa kessleri kessleri (Alosidae) during Spawning Migration in the Volga River
Authors: Zhukova K. A. , Emel’yanova N. G. , Kuzishchin K. V. , Gruzdeva M. A.
Published: April 2024

This paper describes the state of the gonads of Caspian anadromous shad, Alosa kessleri kessleri (Grimm, 1887), migrating for spawning in the Akhtuba River. In May of 2021, the peak of spawning was recorded at a water temperature of 17–18°C. Females and males had gonads at the developing and spawning-capable phases. The fork length (FL) of females averaged 254.1 mm, and their body weight was 178.9 g; for males, this was 209.9 mm and 87.5 g, respectively. Most females were over three years old, while males were between one and three years old. The gonadosomatic index (GSI) in females and males averaged 8.71 and 3.67%, respectively. Among the asynchronously developing secondary growth oocytes in the spawning capable gonads, three different-sized groups were distinguished for intending to spawn the same number of oocyte batches. The number of primary growth oocytes (26.7–59.4% of germ cells on sections) allows for considering these fish as iteroparous. The diameter of the tertiary vitellogenic oocyte was about 800 µm.
Nomenclature of Pigmentation of the Larvae of Lanternfish (Myctophidae)
Authors: Bolshakova Ya. Yu. , Prokofiev A. M.
Published: April 2024

Here we propose a unified terminology for the pigmentation of the lanternfish larvae (Myctophidae). The distinguished two main groups of pigmentation (external and internal) are subdivided into subunits according to their location on the fish body, in total including 77 structural units corresponding to a particular pigment cluster. The use of this nomenclature enables uniform description of pigmentation by different authors. Examples of characteristics of larval pigmentation are given using the proposed nomenclature in the forms of a formal description and summarized diagnostic tables.
Sexual Behavior and Reproductive Success of Guppy Poecillia reticulata (Poeciliidae) at a Constant Temperature and in the Temperature Gradient Field
Authors: Zdanovich V. V.
Published: April 2024

The sexual behavior of males and the reproductive success of the guppy Poecilia reticulata were studied under experimental conditions in a temperature gradient field of 24–28°С and at a constant temperature of 26°С. The intensity of courtship of males for females in the temperature gradient field was 1.6 times higher than at 26°С, while the structure of male sexual behavior changed: the frequency of manifestation of demonstrative forms of behavior and copulations increased. On average, the individual female fecundity was 19.0% higher in the temperature gradient field than in the constant temperature regime. Temperature fluctuations experienced by fish when exposed to a temperature gradient field had a stimulating effect on the intensity of male courtship and the reproductive success of guppies.
Morphometric Analyses of the Angular Roughshark, Oxynotus centrina (Oxynotidae), with Biological Notes on Specimens from the Sea of Marmara
Authors: Kabasakal H. , Uzer U. , Gönülal O. , Akyüz O. , Karakulak F. S.
Published: April 2024

Morphometric measurements as percentages of total length of 6 specimens of Oxynotus centrina (Linnaeus, 1758), captured in the Sea of Marmara were reported. All of the analyzed proportions of landmark measurements as percentage of total length show allometry. Although, slight differences were seen between the morphometrics of Marmara specimens of O. centrina and those reported for the angular roughsharks captured in several geographical subregions of the Mediterranean Sea, these variations can be considered admissible based on allopatry. Regarding the mouth morphology in particular, the proportion of head length/mouth width to total length showed negative allometry, indicating O. centrina is a small-mouthed shark compared to increasing body size. A partly digested shark embryon and vitellus like slurry were found in the stomach content of one specimen captured in the Sea of Marmara, which provided supporting evidence for the predation on elasmobranch eggs by O. centrina in the wild.
New Data on Biology of Siberian Stone Loach Barbatula toni (Nemacheilidae) in Langeri River (Sakhalin)
Authors: Kirillova E. A. , Kirillov P. I.
Published: April 2024

New information on size composition, feeding, and spawning of Siberian stone loach Barbatula toni in a large watercourse in the northeast of Sakhalin Island is reported. The recorded maximal absolute body length and weight comprised 200 mm and 53.3 g, respectively. Predation and cannibalism in large fish specimens have been revealed.
Notes on Hermaphroditism in the Baltic Herring Clupea harengus membras (Clupeidae) in the Gulf of Finland
Authors: Kuznetsov A. F.
Published: April 2024

Two specimens of Baltic herring Clupea harengus membras with anatomically different signs of synchronous hermaphroditism, discovered for the first time in the eastern part of the Gulf of Finland, are described. Individuals with abnormal gonads did not differ from ordinary representatives of the species in other biological characteristics and external morphology. Possible causes of disturbances in the reproductive functions of herring in the studied region are discussed.
Trematode Diplostomum pseudospathaceum (Diplostomidae) Larvae Penetrate the Underyearlings of Oncorhynchus mykiss (Salmonidae) and Manipulate Their Behavior
Authors: Mikheev V. N.
Published: April 2024

Experiments with underyearlings of Oncorhynchus mykiss and cercariae of the trematode Diplostomum pseudospathaceum show that the first parasites that infect the fish have an excitatory influence on it and triple the rate of cercaria income with water through the oral cavity and gills. This effect is considered as manipulation of fish behavior at the stage of parasite transmission from the first intermediate host (mollusk) to the second (fish) one. Experimental data on the effect of fish odor on locomotor activity and the vertical distribution of cercariae have been obtained. Analysis of the data made it possible to determine a set of conditions that ensure the successful infection of fish by diplostomum larvae.
Morphological Сharacterization of the Spinal Cord Regeneration in Adult Desert Killifish Aphaniops hormuzensis (Aphaniidae)
Authors: Motamedi M. , Soltani A. R. , Teimori A.
Published: April 2024

Morphological characterization of the lumbar spinal cord regeneration process was investigated in killifish A. hormuzensis, by using hematoxylin-eosin staining after spinal cord injury. An spinal cord injury was settled, and the injured tissue was sampled. Immediately after the spinal cord injury, the blood clot formation was detected at the injury epicenter and the ependymal layer, and at six hours post-injury (6 hpi), the inflammation and cavity formation occurred. The neural cell accumulation and beginning signs of the spinal cord regeneration were detected one-day post-injury (1 dpi) close to the ependymal layer and subependymal layer. In two 2 dpi, the tissue repair and regeneration progress were detected. The reformation of the ependymal canal happened at 3 dpi, followed by the completion of spinal cord regeneration at 5 dpi. The spinal cord regeneration potency in A. hormuzensis is relatively higher than in other traditional fish models. Studies on the regeneration of this interesting fish are new, therefore, further investigations are needed to explore additional information about various aspects of tissue regeneration. This study is important because killifishes have a short life span, show high environmental variation tolerance, and are easy to maintain and breed in laboratory conditions.
Influence of Hypothyroidism on the Variability of Carotenoid Coloration in Amatitlania nigrofasciata Females (Cichlidae)
Authors: Prazdnikov D. V.
Published: April 2024

The study of the effect of thyroid hormones on the development of the pigment pattern, including the expression of sexual dichromatism, contributes to our understanding of the role of endocrine signaling in the evolution of cichlid fishes, one of the most diverse groups of teleosts. This work shows the effect of reduced thyroid hormone signaling on the development of reversed sexual dichromatism in Amatitlania nigrofasciata, a Neotropical cichlid in which females, unlike males, have carotenoid coloration. In hypothyroid fishes, there was a slowdown in the rate of metamorphic transformations of the pigment pattern and an increase in phenotypic variability. The adult pattern based on carotenoids began to develop in females only after the completion of treatment of thiourea, which suppresses the synthesis of endogenous thyroid hormones. The data obtained indicate a potentially important role of thyroid hormone-mediated developmental plasticity in the diversification of carotenoid coloration in Neotropical cichlids.
Polymers of 2,5-Dihydroxybenzoic Acid Induce Formation of Spheroids in Mammalian Cells
Authors: Rystsov G. K. , Lisov A. V. , Zemskova M. Yu.
Published: April 2024

Cells attached to a substrate and grown in two dimensions (2D) or suspended culture cannot accurately replicate intercellular interactions in tissues and organs. Spheroids, being three-dimensional (3D) formations, are more accurately reproduce the structure of organs or neoplasms. Spheroids compared to 2D cultures demonstrate an increased survival, corresponding morphology, and a hypoxic core, which is observed in native tumors in vivo. Tumor cell spheroids also represent models of the metastatic process. Therefore, spheroids are currently widely used for testing new anticancer drugs. However, obtaining and using 3D cultures can be associated with a number of difficulties, such as the need for expensive reagents and equipment, the low rate of formation of spheroids of the required size, and the occurrence of long-term changes in cell metabolism, which depend on the methods used to create spheroids. We have found that incubation of tumor and normal cells in the presence of polymers of 2,5-dihydroxybenzoic acid (2,5-DHBA) that are nontoxic to cells can induce the formation of 3D structures. Based on this, a new method for the rapid production of 3D cultures is developed and this approach does not require the use of additional equipment, expensive reagents, and does not have a long-term effect on cell homeostasis. The spheroids obtained by this method represent models of three-dimensional structures and can be used for biological studies of intercellular interactions and detection of pharmaceutical products.
Extracellular Cold Shock Protein YB-1 Induces Tolerance to GMDP and LPS in Mouse Macrophage Cell Line J774
Authors: Alekseeva L. G. , Laman A. G. , Meshcherykova E. A. , Shepelyakovskaya A. O. , Brovko F. A. , Ivanov V. T.
Published: April 2024

Cold shock protein YB-1 is involved in the regulation of a huge number of fundamental biological processes. Previously, we showed that YB-1 is also involved in the process of recognition of muramylpeptide GMDP by the innate immune receptor NOD2 and is able upon preliminary administration to protect mice from death in a model of septic shock induced by Escherichia coli bacteria. We hypothesized that its protective effect may be associated with the development of a state of tolerance (“nonresponsiveness”). Changes in the cellular response were assessed by the level of mRNA expression of the target molecules by quantitative PCR analysis combined with reverse transcription. We tested the possibility of tolerance induction by the YB-1 protein in a model system on the J774 mouse macrophage cell line with the participation of E. coli bacterial cell wall components, immunostimulants GMDP (NOD2 receptor agonist) and LPS (TLR4 receptor agonist). Pretreatment of cells with YB-1 resulted in a significant decrease in the level of mRNA expression of pro-inflammatory cytokines IL-1β, TNF-α, and IL-6 in response to further stimulation with GMDP and LPS, as well as significant changes in the expression of mRNA of RIP2 and MyD88 adapter molecules and components of transcriptional factor NF-κB. Our data show that YB-1 is able to induce tolerance to such as GMDP and LPS immunostimulants, apparently by increasing the production of the anti-inflammatory cytokine IL-1Ra and the SOCS1 inhibitor. A more precise characterization of the features of the YB-1-induced tolerogenic immune response requires further research.
From Peptides to Receptors
Authors: Tsetlin V. I.
Published: April 2024

In the 1960s and 1970s, the Institute of Chemistry of Natural Compounds developed a topochemical approach for designing new biologically active peptide compounds, the applicability of which to the creation of inhibitors and effective substrates of proteolytic enzymes was shown by the author of this review under the direct supervision of V.T. Ivanov. The next task was to establish the conformation of protein neurotoxins from snake venoms and to study the topography of their binding to the target, the nicotinic acetylcholine receptor (nAChR) from the electric organ of the Torpedo marmorata ray. With selectively labeled derivatives containing one fluorescent or spin label on established amino acid residues, neurotoxin residues in contact with nAChR were identified for the first time. Later, in collaboration with the laboratory of V.T. Ivanov, new analogues of α-conotoxins (peptide neurotoxins from poisonous mollusks Conus), were synthesized including their photoactivated derivatives, which showed the participation of all Torpedo nAChR subunits in the binding of α‑conotoxins. The final part of the review briefly presents the recent achievements of the Department of Molecular Neuroimmune Signaling (headed by V.I. Tsetlin) concerning the isolation and synthesis of new peptide and protein neurotoxins and the study of their mechanism of action.
Alternative Chromophore Binding Sites in Non-Covalent Fluorescent Complexes of Bacterial Lipocalin
Authors: Goryacheva E. A. , Artemyev I. V. , Arhipova S. F. , Rossohin A. V. , Gilvanov A. R. , Pletnev V. Z. , Pletnevа N. V.
Published: April 2024

The three-dimensional structure of DiB3, a fluorescent non-covalent complex of a genetically engineered variant of the bacterial protein lipocalin Blc with a synthetic GFP-like chromophore M739, was determined by the calculation method of molecular mechanics. Compared to the crystal structure of the related DiB1 complex, an alternative binding site for the M739 chromophore was found in the structure of the DiB3 complex.
Synthesis and Evaluation of the Antiviral Activity of 5-Halogen-2'-Azido-Substituted Derivatives of Cytidine and N-Hydroxycytidine on a Panel of RNA Viruses, Including SARS-CoV-2
Authors: Kamzeeva P. N. , Kozlovskaya L. I. , Belyaev E. S. , Chistov A. A. , Alferova V. A. , Yakovchuk E. V. , Borodulina M. O. , Karpova E. V. , Kolpakova E. S. , Aralov A. V.
Published: April 2024

Coronavirus disease 2019 (COVID-19) is a new global pandemic with high morbidity and mortality caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). N-Hydroxycytidine derivatives show promise for combating viral diseases, and in particular, molnupiravir has recently been approved for emergency prophylaxis in the early stages after infection with SARS-CoV-2. Here, a scheme for the synthesis of 5‑halo-2'-azido-substituted derivatives of cytidine and N-hydroxycytidine is proposed. The synthesized compounds were tested on a panel of six RNA viruses, including SARS-CoV-2, enteroviruses, CHIKV, and HIV-1. A number of compounds were able to inhibit the reproduction of SARS-CoV-2 and CHIKV viruses in the micromolar range without noticeable cytotoxicity. The structures of the leader compounds can be used as a starting point for further design of antiviral agents.
Bacteria Adaptation Mechanisms to Stress Conditions with Small Non-Coding RNAs Participation
Authors: Karpov A. S. , Elkina D. A. , Oretskaya T. S. , Kubareva E. A.
Published: April 2024

Despite the fact that most of the bacterial genome encodes certain protein molecules, with the development of transcriptomic technologies, many genes have been discovered that transcribe RNA which is not translated into proteins. Such RNAs are called non-coding RNAs (ncRNAs). The study of only a small number of them shows that ncRNAs often act as regulatory molecules in various cellular processes: maintenance of cell wall homeostasis, protection against pathogens, virulence, etc. A special place among them is occupied by the so-called small ncRNAs with a length of ~50–300 nucleotide residues. In most cases, they form duplexes with the mRNA of certain genes, which affects the expression of the latter. However, some ncRNAs are able to directly bind to the target protein. Similar mechanisms of action of small ncRNAs give them some advantages in regulating various cellular processes compared to protein regulatory molecules. For example, when responding to an external or internal signal through small ncRNAs, the cell will need to spend less time and resources due to the absence of the translation stage. Moreover, some ncRNAs have no complete complementarity to their target RNAs, which makes the regulation more flexible, as it allows ncRNAs to participate in the response simultaneously to various cellular signals. In this review, we considered the general mechanisms by which various small ncRNAs allow bacteria to adapt to certain stressful conditions, as well as specific examples of their action in various prokaryotic organisms.
The Effect of Starvation on the Antioxidant Complex of the Bivalve Mollusk Anadara kagoshimensis (Tokunaga, 1906) from the Black Sea
Authors: Gostyukhina O. L. , Soldatov A. A.
Published: April 2024

The effect of 30-day starvation on the state of the antioxidant complex and lipid peroxidation in the tissues of the Black Sea bivalve mollusks Anadara kagoshimensis (Tokunaga, 1906) was studied. Mollusks were collec-ted on a mussel and oyster farm near the village Katsiveli (the Southern coast of Crimea, the Black Sea) on April 2020. The mollusks were kept in aquariums with a closed water exchange system with biofiltration of water. The mollusks of the experimental group were not fed for 30 days. The activity of glutathione peroxidase, glutathione reductase, superoxide dismutase, catalase, the content of reduced glutathione and TBA-reactive products were determined. It was found that under fasting conditions the content of TBA-reactive products decreased in the hepatopancreas and the foot of the mollusk, and did not change in the gills. The most pronounced changes in the AO complex – an increase in all the studied parameters – were detected in the hepatopancreas. An increase only in the parameters of the antioxidant glutathione system was found in the foot, and an increase only in the activity of glutathione peroxidase and in the content of reduced glutathione was found in the gills. The results obtained in the study have shown a stable antioxidant-prooxidant ba-lance in the bivalve mollusk A. kagoshimensis under starvation conditions.
Genetic Diversity of mtDNA of the Far Eastern Sea Cucumber Apostichopus japonicus (Selenka, 1867) (Echinodermata: Holothuroidea) in Peter the Great Gulf, Sea of Japan
Authors: Yagodina V. D. , Brykov V. A.
Published: April 2024

The genetic diversity of the Far Eastern sea cucumber Apostichopus japonicus (Selenka, 1867), which lives in Peter the Great Gulf, Sea of Japan has been studied. Five samples were analyzed using the mitochondrial DNA’s COI gene fragment. A total of 16 haplotypes were identified, with high haplotype diversity (0.86767 ± 0.01800) and low nucleotide diversity (0.00759 ± 0.00025). The results using AMOVA and pairwise Fst did not reveal significant genetic differences between the samples from Peter the Great Gulf. Based on the data obtained and the structure of the haplotype network, it was suggested that the Far Eastern sea cucumber lives in non-equilibrium conditions. This relates to the uneven distribution of juveniles, depending on the hydrological regime, the type of soil and the development of mariculture in the water area, as well as a significant illegal catch.
Age-Related and Seasonal Dynamics of Hemocyte Population in the Mussel Crenomytilus grayanus (Dunker, 1853)
Authors: Anisimova A. A. , Diagileva M. N. , Sinenko A. V. , Dmitrieva I. A.
Published: April 2024

The cellular composition of the hemolymph of the mussel Crenomytilus grayanus is represented by hemoblasts, hyalinocytes, basophilic, neutrophilic and acidophilic granulocytes with a significant predominance of the latter. With the age of the mollusk, the average values of the size and granularity of hemocytes increased due to accumulation of granulocytes in the hemolymph (up to 100% of all cells) and their mature highly differentiated acidophilic forms (up to 99% of all cells); this indicates a decrease in the rate of renewal of the cell population. During the autumn period of sexual inertia, the number of cells in the hemolymph of mussels decreased with increasing age of mollusks but without any correlation with the shell size. However, in summer, during the spawning period, the concentration of hemocytes either did not change or increased with increasing body size, directly correlating with the number of young basophilic granulocytes. This correlation may indicate either a relationship between the number of hemocytes and the ability of mussels to reach large sizes, or a higher potency in aged mussels for emergency mobilization of the immune system in the summer season through rapid replenishment of the pool of circulating cells with subsequent redistribution of young and mature cell forms between hemolymph and the internal organs.
Muscle Complexes in the Jaw Apparatus of Teleost Fishes: Structure and Function
Authors: Gromova E. S. , Makhotin V. V.
Published: April 2024

Striated muscles of the teleost fishes sometimes combine into complicated “supramuscular” complexes. In these complexes, individual muscles are connected into parallel combinations and/or in sequential series. A group of parallel muscles combines their forces to carry out a single powerful functional act. Consistently connected muscles obtain thereby an increased amplitude and speed of movements. For the described “supramuscular” complexes, the term “supermuscle” has been proposed. The paper provides an overview of the features of the structure and the function of the supermuscles of the teleost fishes heads with parallel and sequential structures. A variety of causes for the formation of muscle complexes is discussed for different taxa of Teleostei.
The Fatty Acid Composition of a Deep-Sea Acorn Worm Quatuoralisia malakhovi Ezhova et Lukinykh, 2022 (Hemichordata: Enteropneusta)
Authors: Rodkina S. A.
Published: April 2024

This study investigates the fatty acid (FA) composition of total lipids in Quatuoralisia malakhovi Ezhova et Lukinykh, 2022 (Hemichordata: Enteropneusta), a new species of deep-sea acorn worm that was collected on the slope of the Piip Volcano in the Bering Sea. The data obtained indicate that the main components of lipids in Q. malakhovi are fatty acids of bacterial and diatom origin. The food source of the studied species is detritus containing large amounts of not only bacteria, but also diatoms. The results could be used in trophic studies of communities that include Enteropneusta.
Mixing of High Alumina and Magnesium Magmas at Klyuchevskoy Volcano (Kamchatka)
Authors: Khubunaya S. A. , Khubunaya V. S. , Maksimov A. P.
Published: April 2024

Geochemical features of impurity elements and the analysis of mineral composition during crystallization allowed us to reveal traces of mixing of moderately potassic magnesium and high alumina magmas at Klyuchevskoy Volcano. Mineralogical features and distribution of Mg, Fe, Cr, Ni, Co, Al in olivines and clinopyroxenes in magnesium basalts and high alumina andesite basalts from the 1938, 1945, 1966 and 1994 flank and summit eruptions at Klyuchevskoy Volcano give evidence for injection of magnesium basaltic melts into high alumina magma.