bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of oscillatory processes in the cardiovascular system in response to local heating in patients with type 2 diabetes mellitus
Authors: Tikhonova I. V , Tankanag A. V , Guseva I. E , Grinevich A. A
Published: April 2024

A comprehensive spectral analysis was used to assess heart rate variability and skin perfusion pattern of limbs in patients with type 2 diabetes mellitus in response to local heating and to identify significant predictors of physiological and pathological changes in the cardiovascular system. An electrocardiogram and skin perfusion on the forearm and foot were measured using Laser Doppler flowmetry at rest and during local heating in both healthy volunteers and patients with type 2 diabetes. The wavelet analysis was applied to Laser Doppler signals and heart rate variability (based on electrocardiogram signals). ROC analysis was used to evaluate significant predictors. The analysis results of patients with type 2 diabetes were compared with healthy controls. The following changes were observed in patients 1) impairment of skin blood flow reserve on the foot during heating, 2) lower amplitude oscillations in heart rate at rest and during heating, 3) an increase in amplitude of oscillations in the skin blood flow from the forearm in intervals related to respiration and heart activity at rest and during heating, 4) a decrease in amplitude of oscillations in the skin blood flow on the foot in the interval related to myogenic activity at rest and in cardiointerval during heating. The parameters of cardiovascular system (energies of heart rate variability at low-frequencies recorded by laser Doppler flowmetry on forearm in intervals related to respiration activity) with high discriminative power were revealed to distinguish patients from healthy subjects in response to local heating; these parameters can be used as markers for early diagnosis of microvascular disorders.
MICROMORPHOLOGY OF THE LEAF EPIDERMIS SURFACE IN SOME PYRINAE SPECIES (ROSACEAE)
Authors: Babosha A. V. , Ryabchenko A. S. , Kumachova T. Kh.
Published: April 2024

Scanning electron microscopy (cryoSEM) was used to study the micromorphology of the leaf epidermis surface of species of 6 genera: Sorbus L., Aronia Medik., Amelanchier Medik., Cydonia Mill., Cotoneaster Medik., Crataegus L. (Rosaceae). The surface of the leaves of the studied plants has two types of cuticular folding. In C. melanocarpus and S. aucuparia, larger and sometimes branched single cuticular strands, usually located on one cell, were observed. In other species, the folding has the form of numerous smaller parallel microstrands running along the long axis of the cell. Different degree of manifestation of both types of cuticular folding was observed on the surface of main epidermal cells on one or both sides of the leaf blades. In addition, the stomata and trichomes were surrounded by radial striations. Microstrands in A. spicata and S. aucuparia were also present on papillae in the area of stomata. All the studied species show stomatal dimorphism. Larger primary stomata with more pronounced cuticular strands are located at some distance or in the center of a group of several smaller secondary stomata. The proportion of primary stomata ranged from 5 to 17%. In the studied species, there is a negative correlation between the stomata length and stomata density, which is close to such correlation in other taxa.
REFORESTATION PROCESS AFTER A GROUND FIRE AND CLEAR CUTTING IN LIANA-VARIED-SHRUB BROAD-LEAVED-DARK-CONIFEROUS-KOREAN-PINE FORESTS OF SOUTHERN SIKHOTE-ALIN
Authors: Komarova T. A. , Terekhina N. V. , Prokhorenko N. B. , Glushko S. G.
Published: April 2024

A comparative analysis of the formation and natural course of development of plant communities was carried out in two plots: (1) passed through by a stable ground fire and (2) subjected to experimental clear cutting with preserving young generation of tree species in liana-varied-shrub broad-leaved-dark-coniferous-Korean-pine forests of the mid-mountain belt of the Southern Sikhote-Alin. The features of natural recovery, course of growth, development and dynamics of the number of woody plants in the first 35 years of the reforestation process are considered. Taxation characteristic of the forest stands before their destruction by the fire and cutting, as well as at the first stages of the formation of young tree stands, are given. The dynamics of the species composition and phytomass of the aboveground parts of plants of the shrub and low-shrub-herb layers is considered.
ЧИСЛА ХРОМОСОМ НЕКОТОРЫХ ТАКСОНОВ ASTERACEAE СТАРОГО И НОВОГО СВЕТА
Authors: Krivenko D. A. , Vinogradova Yu. K.
Published: April 2024

Представлены числа хромосом (2n) и уровень плоидности (nx), в соответствии с предполагаемым основным числом хромосом (x), для 35 видов, подвидов, нотовидов, а также гибридов из 17 родов семейства Asteraceae (Compositae): Aster (1), Amberboa (1), Carduus (1), Centaurea (4), Cirsium (1), Crepis (1), Erigeron (5), Hieracium (1), Hypochaeris (1), Leontopodium (1), Pilosella (1), Scorzoneroides (1), Solidago (9), Sonchus (2), Taraxacum (2), Tragopogon (2), и Tripleurospermum (1). Изучаемые экземпляры – происхождением из Европы (европейская часть России, Франция и Великобритания, включая ее коронные земли), Кавказа (Армения и Россия), Центральной Азии (Таджикистан), Сибири (Иркутская область и Республика Бурятия), Дальнего Востока России (Приморский край) и Северной Америки (США). Впервые число хромосом определено у Centaurea cheiranthifolia subsp. willdenowii (2n = 18 + 0–2B). Неизвестное ранее число хромосом (цитотип) установлено у Solidago × snarskisii (2n = 36). Для других таксонов были подтверждены ранее известные числа хромосом.
MOSSES OF THE WESTERN PART OF THE CHUKCHI HIGHLANDS. 3. INTERDEPENDENCE OF PERCENT COVER VALUES OF MOSSES AND VASCULAR PLANTS
Authors: Kholod S. S. , Afonina O. M.
Published: April 2024

In previous publications (Kholod, Afonina, 2023a, b) the dependences of the number of moss species and the values of moss percent cover in the western part of the Chukchi Highlands on a number of abiotic factors were considered. This article discusses the interdependence of the percent cover values of mosses and vascular plants in this area. On the slopes of most aspects, an increase in the percent cover values of vascular plants to a value of 65–75% is accompanied by an increase in the percent cover values of mosses (up to 40–70%), which decreases with a further increase in the percent cover values of vascular plants. Two groups of bryocenotypes, one of them being formed on dry, relatively steep slopes of the southern and western aspects with rapidly descending snow, and the other on wet, snow-covered gentle slopes of the northern and eastern aspects, characterize 2 types of natural environments of the Pleistocene-Holocene: cooling with active freezing of loose strata of slopes, and warming with intense permafrost melting and activation of slope processes, respectively. The linear relationship between the values of the percent cover of vascular plants and mosses, on the one hand, and the area of unpaved soil, on the other, is considered as a model of the settlement of soils by mosses during the transition from cold climatic epochs to warm ones. In such transitional epochs, vascular plants have an advantage in the percent cover values at the initial stage, then, with the growth of mosses, the increase in the percent cover values of vascular plants slows down, which is a manifestation of the regulatory influence of mosses through the availability of accessible water and a number of other parameters.
MACROPHYTES OF THE LITTORAL ZONE IN LAKES OF SPECIALLY PROTECTED NATURAL AREAS OF THE ARKHANGELSK REGION
Authors: Moseev D. S. , Parinova T. A. , Volkov A. G. , Bragin A. V. , Sergienko L. A.
Published: April 2024

The article analyzes distribution of 94 species of aquatic plants in 18 lakes, different in size, origin, trophic status, hydrological and hydrochemical conditions. Macrophytes and their communities were studied in 11 large and small lakes in the Kenozersky National Park, in 2 large lakes in the Onezhskoye Pomorye National Park, and in 5 small lakes in the Pinezhsky State Nature Reserve. The eutrophic lake Porzhenskoye in the Kenozersky National Park stands out with the greatest species number, 52 species. Fewer species of macrophytes were identified in oligotrophic lakes. It is shown that the majority of aquatic plants of the Arkhangelsk Region inhabit narrow range from low to medium total dissolved solids – 54 species. Eurybiont species, occurring in a large range of total dissolved solids from 1 to 1020 mg/l, show a great species diversity – 24 species. Only 11 species tend to grow in karst lakes with elevated level of total dissolved solids from 500 to 1020 mg/l – vascular plants: Ranunculus kauffmannii, Eleocharis acicularis, E. quinqueflora, Myriophyllum verticillatum, Potamogeton obtusifolius, Stuckenia pectinata, Sparganium hyperboreum; mosses: Calliergon cordifolium, Scorpidium scorpioides; algae: Chara aspera, C. subspinosa. The majority of species in the lakes of specially protected natural areas of the Arkhangelsk Region, growing in a narrow water pH range, are neutrophytes – 31 and neutro-alkalophytes – 27. Thirteen protected species of macrophytes were discovered in the flora of lakes in the Arkhangelsk Region – Chara aspera, C. strigosa, C. subspinosa, C. virgata, Fissidens fontanus, Fontinalis dalecarlica, F. hypnoides, Isoëtes echinospora, I. lacustris, Lobelia dortmanna, Nymphaea candida, N. tetragona, Sparganium gramineum.
STRUCTURE OF BICARPELLATE GYNOECIUM IN SYMPHYTUM ASPERUM (BORAGINACEAE) IN RELATION TO EREM FORMATION
Authors: Shamrov I. I. , Anisimova G. M.
Published: April 2024

The genesis of the bicarpellate syncarpous gynoecium was analysed in Symphytum asperum in relation to the septa formation in it, which determines the structure of erems (a dispersal unit of schizogenetic fruits forming as a result of dividing each carpel of syncarpous gynoecium into two independent parts) and the coenobium as a whole. In the gynoecium, at early stages of development, a short fertile synascidiate zone arises due to the formation of a basal septum (septum of 1st type) at the fusing of the involute carpel edges. A symplicate zone is formed above. A double U-shaped synplacenta appears at the gynoecium base. The structure of the basal septum is characterized by some features. The sutures that form the septum are obsagittate, with their wide part directed towards the center, and their narrow part directed outward. The septum of the 1st type is characterized by a 4-rayed structure, resembling an elongated rhombus or 2 tetrahedral pyramids facing each other: short rays are located between the walls of emerging erems of the same carpel, and long rays are between the walls of the erems of adjacent carpels. The central part of the septum subsequently stops developing, and the rays are transformed into branches of syncarpous sutures (2 in each carpel), to form 4 septa of the 2nd type. The length of the septa of the 2nd type increases longitudinally. In the wall of the ovary on the dorsal side in the area of the vascular bundle, 4 strands of small thin-walled cells are formed. Then, a splitting of these strands and the dorsal vascular bundle in half takes place. The septa of the 2nd type, like curtains or inserts, connect open ventral margins with dorsal halves of the ovary wall in each carpel, later becoming part of the pericarp of single-celled erems. At the same time, the symplicate zone is divided into 4 independent compartments. In S. asperum, septa of the 2nd type do not divide the loculi of carpels into 2 compartments and are not united into single partitions. They remain autonomous, growing between open edges of the halves in each carpel. The resulting diaspores (erems) are surrounded by a fruit coat on all sides. The outgrowths are not detected between the erems. This growth of the septa of the 2nd type is unique and correlates with the growth of the gynobasic style, while the shape of the growing septa ideally coincides with the shape of its faces.
INFLUENCE OF CRUDE OIL ON THE DEVELOPMENT OF ZYGOTES AND SEEDLINGS OF THE GREEN ALGA ULVA LACTUCA (ULVACEAE) OF THE BARENTS SEA
Authors: Salakhov D. O. , Pugovkin D. V. , Voskoboinikov G. M.
Published: April 2024

The ability of the zygotes and seedlings of the green alga Ulva lactuca to develop under the influence of crude oil in various concentrations was determined. The oil at a content of 1 mg/l in water does not have a damaging effect on the germination of zygotes and their further development into multicellular seedlings. Juvenile seedlings have a wider tolerance range than zygotes and can develop under oil content in marine water up to 3 mg/l. The real threat of the death of zygotes, which rovide replenishment of ulva algae thickets in the littoral with young thalli, is observed under short-term oil pollution of more than 25 mg/l, or with constant oil pollution of more than 5 mg/l. The oil content in water of  25 mg/l and above stops the development of most seedlings by irreversibe destroying the structure of their cells.
THE EFFECT OF COLD TREATMENT ON THE GERMINATION OF CARDIOCRINUM CORDATUM VAR. GLEHNII (LILIACEAE) SEEDS
Authors: Butuzova О. G. , Kovaleva A. A. , Andronova E V.
Published: April 2024

The seeds of Cardiocrinum cordatum var. glehnii are characterized by a complex morphophysiological type of dormancy. There are three mechanisms of germination inhibition: two of them are localized in the embryo and one in the surrounding structures of the seed. To overcome these mechanisms, different temperature regimes for seed stratification are required.It was revealed that the mechanism of inhibition of embryo postdevelopment is removed at higher temperatures of 18–20°C for 1.5 months for stored seeds or 2 months for fresh ones. Optimal rates of embryo development were observed at 9–10°C. At the end of postdevelopment, the embryos in different experimental variants could significantly differ in length. However, the degree of heterogeneity of the sample by embryo length did not affect the germination rate and the final percentage of germinated seeds.@The temperature regime during embryo postdevelopment did not affect the subsequent growth of the embryonic root and seed germination, as well as cold stratification at the beginning of the experiment did not stimulate embryo growth.The development of embryo root was possible only after exposure to cold (0–2°C). It was demonstrated that the energy of seed germination and the germination rate significantly depend on the duration of cold stratification, regardless of the moment of exposure to cold. The longer the cold treatment was, the faster the seed germination. At the same time, not only cold stratification on water, but also dry storage of seeds at 0–2°C accelerated their germination.Under natural conditions, seed germination of  C. cordatum var. glehnii occurs in 18–19 months after dissemination. In laboratory experiment, freshly harvested seeds of this species could be germinated in 7–8 months, taking into account that approximately 4 months of warm stratification are required for the further development of the embryo, and 3.5–4 months of cold stratification are required to remove the mechanism of germination inhibition.Differences in the duration and period of exposure to cold, however, did not affect the final percentage of germinated seeds. In almost all variants, the final percentage of germination was high (from 86 to 100%).The results of the experiment indicate that the process of seed germination of C. cordatum var. glehnii is realized in nature under the effect of different durations of temperature influences, which ensures the plasticity in the reproduction of this species in natural conditions.
CRYPTOHYBRIDS IN PLANTS: UNDERWATER PART OF THE ICEBERG
Authors: Shneyer V. S. , Punina E. O. , Domashkina V. V. , Rodionov A. V.
Published: April 2024

Interspecific hybridization is widespread in plants and is the most important factor in their evolution. For a long time, the main criterion for the hybrid origin of a plant was considered to be the morphological intermediacy of noticeable external characters. However, as the methods of chemistry and molecular biology are introduced into systematics and larger samples are studied, the researches increasingly identify the plants which are chemically and genetically hybrid, but are outwardly indistinguishable from the hypothetical parents or have an unusual combination of traits that does not allow us to recognize the hybridity and the parents by morphology.Subsequent closer study of such identified “molecular hybrids” with application of morphometry often makes it possible to find morphological, often quantitative or microscopic characteristics which confirm the hybrid nature of these plants as well. Identification and study of cryptic hybrids is important for the systematics of complex taxonomic groups with wide phenotypic plasticity, with a large number of similar species, and simplified morphology. It helps to better understand the conditions under which hybridization can occur, and is important in practical terms, especially for the control of invasive species, for the protection of rare and endangered species, etc.
Polyunsaturated Fatty Acid Content in the Muscles of Alien Fish Species of the Rybinsk Reservoir
Authors: Dgebuadze Yu. Yu. , Sushchik N. N. , Gerasimov Yu. V. , Solomatin Yu. I. , Gladyshev M. I.
Published: April 2024

The biochemical composition of the muscles of two fish species, European smelt Osmerus eperlanus and the Common (Caspian) kilka Clupeonella cultriventris, that were successively invaded and naturalized in the Rybinsk Reservoir in the second half of the 20th century, differs significantly in the fatty acid content. The sum content (mg/g) of eicosapentaenoic (20:5n-3) and docosahexaenoic (22:6n-3) polyunsaturated fatty acids in the muscle tissue of the kilka is almost four times higher than that in European smelt. Given that smelt and the kilka are similar in their ecological and morphological characteristics and do not differ significantly in the composition of their diet in the Rybinsk Reservoir, it is obvious that the observed differences primarily result from the phylogenetic aspect. The obtained data on the composition of the fatty acids of the invaders show that the replacement of one alien species with another (European smelt with the kilka) significantly changed the quality of production of an important link in the trophic web of the reservoir.
Scale-Based Study of Linear Growth Rate of Pink Salmon Oncorhynchus gorbuscha (Salmonidae)
Authors: Kaev A. M. , Romasenko L. V. , Kaev D. A.
Published: April 2024

The retrospective study of the linear growth of pink salmon Oncorhynchus gorbuscha based on measurements of the scales of the fish returned to spawn has been performed at the southeastern coast of Sakhalin Island in 2005–2020. Growth characteristics, such as the increase in its length during sclerite formation, variability and asymmetry of the size composition during growth, are compared with the survival rate of the corresponding generations. Correlation of growth rate with the survival rate of the corresponding generations is observed only during the early marine period of life. The changes in the calculated size composition in surviving fish are similar to some extent to those traced for establishing generations. This phenomenon increases the share of uncertainty in the estimates of size-selective mortality when comparing the body length of underyearlings calculated from the scales with actually observed ones.
Differentiation of Arctic Charr Salvelinus alpinus Complex (Salmonidae) in Lakes Lama and Kapchuk (Taimyr) Based on Genetic Analysis, External Morphology, and Otolith Shape
Authors: Pavlov D. A. , Osinov A. G.
Published: April 2024

The analysis of 17 microsatellite loci reveals five general forms of Arctic charr Salvelinus alpinus in large lakes Lama and Kapchuk (Norilo-Pyasinskaya water system, Taimyr) connected by the river. Three of them are represented by sister pairs, and, thus, eight reproductively isolated forms are defined. The immature individuals of different forms are hardly identified by external morphology. For the morphological differentiation of the five general forms, multivariate analyses of morphometric parameters of the body, otolith shape indices, and wavelet coefficients describing otolith contours are applied. All analyses show that goggle-eyed charr (“pucheglazka”) substantially differs from the other forms. The relationships between the four other general forms are variable depending on the method of analysis. Besides, a certain difference is observed in the data evaluating the left and right otolith shapes. The total correct jack-knifed classification of the forms in the linear discriminant analyses is 55.9% for morphometric indices and reaches 56.1 and 61.4% for the left and right otolith shapes assessed by wavelet transform. The overall morphological similarity of the forms can be explained by their parallel evolution in a restricted number of available trophic niches.
Age-Related Melanism in Macroparalepis brevis (Paralepididae)
Authors: Prokofiev A. M.
Published: April 2024

Age-related melanism for a dwarf species of the genus Macroparalepis, M. brevis, was described for the first time; thus, this phenomenon turns out to be a common generic character. Presumably, the trigger for coloration change is the transition to a mesobenthic lifestyle. The phylogenetic significance of age-related melanism in barracudinas (Paralepididae) is discussed, which may support a kinship of the genera Macroparalepis and Stemonosudis (including Dolichosudis). The species D. fuliginosa was recorded in the Indian Ocean for the first time.
The Role of Respawning Individuals in the Reproduction of Atlantic Salmon Salmo salar (Salmonidae). Mathematical Simulation
Authors: Alekseev M. Yu.
Published: April 2024

Analysis of long-term fishing and biological data has made it possible to determine the proportion of respawning individuals (the “remainder”) in populations of Atlantic salmon Salmo salar inhabiting large rivers of the Kola Peninsula. The contribution of respawning individuals to the dynamics of the Atlantic salmon population was assessed using the mathematical simulation model. It is shown that the model population becomes more resistant to fishing with increase in the “remainder” proportion; however, the influence of such individuals on the population dynamics is noticeable only when their relative number is more than 5% in the spawning population. The results of different model experiments are interpreted. The role of respawning salmons may be determined not so much by their quantitative contribution to the reproduction process as by the maintenance of the genetic diversity of the population within the reproductive strategy characteristic of the Atlantic salmon
First Finding of Larvae of an Undescribed Species of the Genus Lyconus (Lyconidae) in the North Pacific Ocean
Authors: Bolshakova  Ya. Yu. , Evseenko S. A.
Published: April 2024

The first illustrated description of two larvae of the rare deep-water genus Lyconus from the North Pacific Ocean has been given. The studied specimens differ from the previously described larvae of L. pinnatus in complete and uniform pigmentation of the body. The new materials complement the existing ideas about the geographical distribution of representatives of the family Lyconidae – this is their first finding in the waters of the Pacific Ocean.
New Record of the False Pike Conger Eel, Congrhynchus talabonoides (Anguilliformes: Congridae) from the Arabian Sea
Authors: Kodeeswaran P. , Ajith Kumar T. T. , Kumar Lal K.
Published: April 2024

The False Pike Conger Eel, Congrhynchus talabonoides Fowler, 1934 (n = 5) was reported for the first time from the southwest coast of India, Arabian Sea, previously the species was known only from Taiwan, Philippines and Andaman Sea. Diagnostic characters for the species have been provided. Further, the mitochondrial COI gene was generated and the phylogenetic position of C. talabonoides is discussed.
Hematological and Genotoxic Indicators of the Freshwater Beam Abramis brama and Prussian Carp Carassius gibelio (Cyprinidae) in the Volga Delta
Authors: Konkova A. V. , Faizulina D. R. , Shirina Yu. M. , Bogatov I. A. , Astafieva S. S. , Zhukova K. A.
Published: April 2024

The occurrence of erythrocytes with micronuclei and DNA damage was detected by the comet assay in freshwater bream, Abramis brama, of age 3–4, and prussian carp, Carassius gibelio, of age 4–5 from Volga delta in September 2021. The average frequency of erythrocytes with micronuclei in the studied fish es was within the normal range for cells formed during spontaneous mutagenesis (0.5–1.0‰). Further, 25% freshwater bream and 26.6% Prussian carp exceeded this limit. The genetic damage index (GDI), which reflects primary DNA damage, was 0.21 ± 0.03 and 0.26 ± 0.02 in freshwater bream and Prussian carp, respectively. Further, it correlated (r = 0.71, p 0.05) in Prussian carp with the occurrence of erythrocytes with micronuclei. Hematological and biochemical parameters of the mentioned species were within typical limits for fishes residing in water bodies with a weak anthropogenic load. The results allow considering the existing conditions of the freshwater bream and Prussian carp in the Volga delta as quite favorable in relation to the genotoxic situation.
Tributary-Specific Contribution to a Lacustrine Mixed-Stock Fishery of Brown Trout Salmo trutta (Salmonidae) in a Diverse Sub-Arctic Watershed
Authors: Mikheev P. B. , Prusov S. V. , Erkinaro J. , Samokhvalov I. V. , Dolotov S. I. , Potutkin A. G. , Orell P. , Seppänen M. , Kopylov I. S. , Puzik A. Yu. , Easton R. , Reid M. , Closs G.
Published: April 2024

Mixed-stock fisheries which simultaneously cause mortality amongst several populations of a species of fish may occur where separate stocks partially or completely overlap in the geographic area of harvest. This study aims to analyze the population-of-origin of adult and subadult adfluvial lacustrine brown trout Salmo trutta, exploited in a mixed-stock fishery in Upper Tuloma Reservoir in Eastern Fennoscandia, using otolith microchemistry. To evaluate the origin of migratory brown trout captured in these mixed-stock harvest fisheries, we undertook otolith sampling of brown trout juveniles in fluvial spawning and rearing habitats in the reservoir watershed, including 13 natal tributaries across the catchment of the reservoir in both Russia and Finland. Harvested adult and subadult brown trout otoliths were sampled from the impoundment in the central area of the reservoir and we analyzed for stock-related character differences to compare with known populations, using trace element signatures, with fish from the mixed stock fishery. The assignments-of-origin in the mixed-stock fishery-harvest samples did not follow the known distribution of populations sampled from natal streams in the watershed. For example, brown trout from the largest tributary catchments of Lotta River and Nota River were less represented in the mixed-harvest sample, which was contradictory to their contribution to the overall spawning and rearing areas of the catchment. These results point towards the importance of maintaining the diversity of different spawning and rearing tributaries required for brown trout recruitment into mixed stock fisheries, and the potential of the existence of population structure of brown trout in the reservoir catchment. Our information suggests that it is important to develop conservation and management strategies for natal habitats in multiple streams utilized by adfluvial lacustrine brown trout populations inhabiting various catchments and that are harvested in mixed-stock fisheries.
New Species of the Damselfish Genus Chromis (Pomacentridae) from Vietnam
Authors: Prokofiev A. M. , Astakhov D. A.
Published: April 2024

A new species, Chromis oligactis from the coast of Khanh Hoa province (Vietnam, South China Sea) has been described, which is characterized by a moderately deep body (contained 2.2 times in the standard length), fin formula D XIV, 10; A II, 10; P i, 15–16; three spiniform procurrent rays of the caudal fin, 26 gill-rakers in the outer row on the first arch, and 19 perforated scales in the anterior lateral line. The holotype of the new species was caught at shallow depths, which is not typical for Indo-Pacific species of Chromis with 14 spinous rays in the dorsal fin.
Modern Concepts on the Origin and Distribution of Acipenserids (Acipenseridae)
Authors: Ruban G. I.
Published: April 2024

The current data on the place and time of origin of Acipenseriformes and the family Acipenseridae, as well as on their distribution in connection with the history of the development of sea and river basins, are summarized. The supposed areas of the initial radiation of Acipenseriformes and their long-term habitation were in eastern Laurasia on a part of the modern Chita Region, Eastern and Central Mongolia, and northern and northeastern China. The eastern part of Asia should also be considered the place of origin of the family Acipenseridae. The widespread distribution of Acipenseriformes was facilitated mainly by the formation of diadromous forms from primarily freshwater species, the origin of which is associated with multiple transgressions and regressions of the ocean. Modern potamodromous acipenserids were probably formed as a result of the return of anadromous forms to living in fresh water; i.e., they are secondarily freshwater species
A New Species of Golden Loach (genus Sabanejewia, Cobitidae) from the Sea of Azov Basin
Authors: Vasil’eva E. D. , Vasil’ev V. P.
Published: April 2024

A new species of golden loach is described from the Don River basin. This species is distinguished from all other Sabanejewia species by the following set of characters: a midlateral row of relatively large 9–16 (more often 13–14) dark blotches along flank usually well developed; no black line along flank; interspaces between midlateral blotches usually with dark pigmentation; some individuals with uniform dark lateral coloration; dorsal fin origin usually in front of pelvic fin origin; body relatively low: body depth noticeably less than the length of the caudal peduncle, usually does not reach 17% standard length—SL, it is contained more than 6 times in SL; dorsal adipose crest on caudal peduncle very weakly developed, ventral crest poorly visible; two black spots at caudal fin base usually merge with each other. Previously, this species was considered conspecific for S. baltica distributed in the Black and Baltic Sea basins, but recent phylogenetic studies have shown that they belong to separate mtDNA phylogenetic lineages
Diet Composition and Reproductive Properties of European Conger, Conger conger (Congridae) in the Turkish Aegean Sea
Authors: Bayhan  B. , Taylan B.
Published: April 2024

The diet composition and reproductive properties of European conger, Conger conger (Linnaeus, 1758) were investigated from the Aegean Sea of Türkiye to compare our data with those from other regions of the Mediterranean Sea and throughout all four seasons. A total of 100 individuals were examined. Totally 19 prey taxa belonging to three large taxon (cephalopods, crustaceans, and fishes) were identified in the stomachs of European conger. According to the relative significance index the crustaceans were dominant food in diet of individuals smaller than 50 cm, while fish prevailed in diet of fish with length between 75 and 100 cm. Histological analysis of 80 gonads showed that all individuals were immature (20%) and maturuing females (80%). Maturing females were with oocytes in the previtellogenic (16% of all fishes) and early vitellogenic phases (64%). The oocyte diameters were 80–476 μm at previtellogenic (diameter range 80–240 μm) and 245–476 μm at early vitellogenic individuals. Immature females had the gonads with the oocyte diameter 30 μm
Feeding Ecology of Red Seabream, Pagrus major (Sparidae) in the Korea Strait
Authors: Jin S. , Kim D. G. , Seong G. C. , Kang D. Y. , Jeong J. M. , Kim H. J. , Baeck G. W.
Published: April 2024

The feeding ecology of red seabream, Pagrus major was studied using 1046 specimens collected by danish seine and bottom trawl from January to December 2018 in the Korea Strait. The size of the individuals ranged from 18.4 to 70.4 cm in fork length. Red seabream was a carnivore that consumed mainly anthozoans, brachyurans, and cephalopods. Its diets included also small quantities of amphipods, anomurans, ophiurids, gastropods, polychaetas, etc. We calculated the trophic level as 3.57 for red seabream. As red seabream grows, the proportion of relatively small prey items such as anomurans and ophiuroids decreases, while that of large prey items such as anthozoans, brachyurans, and cephalopods increases. In the largest size class (≥45 cm FL), cephalopods and pisces are its main prey. Alsoe, the body size of red seabream increased the mean weight of prey per stomach tended to increase significantly (One-way ANOVA: p 0.05). The diet composition of red seabream showed seasonal changes. The cephalopods were the dominant prey items for all seasons. The weight proportion of brachyurans was higher in summer and autumn, whereas anthozoans feeding rate was the highest in winter. PERMANOVA analysis showed significant variations among size classes and seasons. The feeding intensity by size class and season observed no significant difference (One-way ANOVA: p 0.05). As a result of the feeding strategy analysis, red seabream was a generalized feeder, with a wide niche width.
Factors Determining the Replenishment of Pink Salmon Oncorhynchus gorbuscha (Salmonidae) on Iturup Island
Authors: Ostrovskiy V. I. , Kaev A. M.
Published: April 2024

Based on the data on the abundance of 53 generations of pink salmon Oncorhynchus gorbuscha of Iturup Island (spawners on spawning grounds, downstream migrating juveniles and the return of mature fish), a model describing the dependence of the abundance of mature pink salmon offspring on the initial abundance of generations and the effect of external factors was constructed using nonlinear regression analysis. The model explains about 80% of the replenishment variability, and it depends more on the effect of external factors in the freshwater period of life. The variability of replenishment is most closely related to factors related to the hydrological regime of rivers. The dependence of replenishment on the abundance of juveniles migrating downstream from spawning grounds, described by the dome-shaped curve, indicates the limiting effect of density factors on the formation of the abundance of pink salmon during the marine period of life. At the same time, a statistically significant effect of the abundance of juveniles released from fish hatcheries on the dynamics of the replenishment was not found.
The Upper Rio Paraguay Basin Reveals Another Jewel Hidden: Hypostomus uruguayensis (Loricariidae)
Authors: De Oliveira P. V. R. , Azevedo F. M. , Zawadzki C. H.
Published: April 2024

The present work extends the distribution of Hypostomus uruguayensis to the upper Rio Paraguay basin. This species which was originally described from the Rio Uruguay in Southern Brazil and cited to Argentina and Bolivia is here reported for the first time within the Brazilian Midwest. Additionally, the new population was compared to the original description and the holotype of H. uruguayensis, providing a foundation for brief comments on a diagnosis of H. uruguayensis.
Ichthyofauna of the Fresh and Brackish Waters of Russia and Adjacent Areas: Annotated List with Taxonomic Comments. 2. Order Cypriniformes, Suborders Catostomoidei, Cobitoidei and Cyprinoidei
Authors: Dyldin Yu. V. , Orlov A. M. , Hanel L. , Romanov V. I. , Fricke R. , Vasil’eva E. D.
Published: April 2024

This paper is the second part of the “Ichthyofauna of the Fresh and Brackish Waters of Russia and Adjacent Areas: Annotated List with Taxonomic Comments”, which we started in 2022 based on a critical analysis of scientific publications of the last 200 years, and on the data of the author’s research. The current paper includes all currently known fishes of the order Cypriniformes of Russia and adjacent waters, represented by three suborders Catostomoidei, Cobitoidei and Cyprinoidei, comprising ten families, 64 genera and 177 species. The most specious families were the Leuciscidae (59 species/33.3% of all species), Gobionidae (35/19.8%) and Xenocyprididae (23/13.0%), which together represent just over 66% the total cypriniform species. Fourteen of the studied species (24.7% of all cyprinids in Russia) are introduced species, 21 species (11.9%) are endemic; 32 species (18.1%) are recorded from Russia for the first time. In relation to the habitat, 131 species live and breed exclusively in fresh waters, 31 species are of freshwater origin, but can also tolerate slightly brackish waters, ten species are represented by anadromous forms (all with residential populations), and three species are amphidromic, capable of live and reproduce both in brackish water and in freshwater. According to the IUCN criteria, the majority of fish are classified as Least Concern (135 species/76.3%), but two species, Cobitis taurica and Gobio tauricus, are Critically Endangered.
Structure of Aggressive Behavior in Underyearlings of the Rainbow Trout Oncorhynchus mykiss (Salmonidae) Changes under the Influence of Diplostomum pseudospathaceum (Trematoda) Parasites
Authors: Mikheev V. N. , Pasternak A. F.
Published: April 2024

The dynamics of aggressive behavior of the underyearlings of the rainbow trout Oncorhynchus mykiss infected with metacercariae of the trematodes Diplostomum pseudospathaceum has been studied in an experimental heterogeneous environment for 48 days. The fish competed for the dark area of the bottom by charges, biting, chasing, and frontal and lateral displays. The sharply increased aggressiveness of fish when the parasites became infective (1.0–1.5 months after infection), i.e., capable of infecting the final host (piscivorous birds), manifested itself in an increased frequency of bites (more than 20 times compared to the control) and charges (almost three times) and was accompanied by fast movements, sharp maneuvers, and low ability to compete for shelters. The share of comparatively slow displays and chasing was much smaller. The strategy of D. pseudospathaceum manipulation of fish behavior consists of two stages: (1) protecting the host from predators; (2) increasing the vulnerability of the host. At the first stage, the general level of aggression decreases sharply; at the second, on the contrary, aggressiveness rapidly increases, but the ratio of different categories of aggression changes. The share of categories that make the host more vulnerable to predators increases. High activity and low competitiveness of infected fish contribute to their rapid extermination by predators or moving to another habitat. Such migration of fish can increase the fitness of the parasite, facilitating its dispersal in the water body.
Mitogenome Characterization of a Vulnerable Gastromyzontid Fish, Beaufortia pingi (Gastromyzontidae): Genome Description and Phylogenetic Considerations
Authors: Shen Z. , Sheng Q. , Jin Z. , Zhang Y. , Lv H.
Published: April 2024

The hillstream loaches are a species-rich group that are well adapted to fast-flowing freshwater habitats. Loss of habitat owing to the construction of hydropower dams makes these fishes vulnerable. The phylogeny of the genus Beaufortia remains contentious according to previous studies. To help clarify the phylogenetic relationships of Beaufortia and related species, we sequenced and analyzed the complete mitogenome of B. pingi. The circular mitogenome is 16 565 b.p. long and contains 13 protein-coding genes (PCGs), 22 transport RNA genes, two ribosomal RNA genes, and one control region. The most-common codon in PCGs was leucine (16.66%), followed by alanine (9.32%) and threonine (7.71%). A phylogenetic analysis including 17 other species of hillstream loaches was performed using the maximum-likelihood method, based on the sequences of 13 mitochondrial PCGs. These species divided into two clades: Gastromyzontidae and Balitoridae, and some genera, including Beaufortia, appeared paraphyletic. Specifically, B. pingi grouped with Erromyzon kalotaenia, Yaoshania pachychilus, and Pseudogastromyzon fangi, followed by clustering with two other species of Beaufortia.
Comparative Analysis of Natural- and Hatchery-Origin Chum Salmon Oncorhynchus keta (Salmonidae) Spawners Identified in Mixed Stock with Otolith Marking
Authors: Zelennikov O. V. , Myakishev M. S. , Vorozhtsova A. A. , Martynova A. S. , Sedunov P. A.
Published: April 2024

The body length and weight of the hatchery- and natural-origin chum salmon Oncorhynchus keta spawners (identified with the otolith marking technique) in the commercial stock in the Yasnomorka River and the Yasnomorskoe salmon stocking fish hatchery were analyzed in 2015–2019. The proportion of hatchery-origin fish comprised 65.5%, varying from 37.2 to 72.9% from year to year. In addition, 9.2% of specimens had the otolith marks provided by the adjacent salmon stocking fish hatcheries, such as the Sokolniki and Kalinin enterprises. The body weight of the natural- and hatchery-origin chum salmon spawners entered the river for spawning for each age group was not different with a few exceptions. However, the females and males spawn naturally tended to reach the sex maturity at the earlier age, on average, in all their generations for a five-year observation, when compared that to the hatchery-origin fish. Overall, the proportion of fish aged 2+ to 3+ among the hatchery- and natural-origin females comprised 25.1 and 61.5%, respectively. With respect to the hatchery- and natural-origin males, the proportions made up 32.2 and 69.0%, respectively.
Population Structure of European Whitefish Coregonus lavaretus (Salmonidae: Coregoninae) from the Lake–River System of the Subpolar Urals
Authors: Boznak  E. I. , Ponomarev V. I.
Published: April 2024

This paper presents the first description of the population structure of sparsely rakered whitefish Coregonus lavaretus, which lives in the mountain lake–river system of the middle reaches of the Maly Patok River (a second order tributary of the Pechora River). It has been established that European whitefish has formed a complex system of local groups here, which are associated with small lakes of different types, located on the catchment area of this river. A relatively isolated whitefish lacustrine group, which differs in the pattern of the population dynamics and a rapid linear growth of individuals, has been formed in one of the water bodies. There is a temporary aggregation of whitefish in a small endorheic lake, which is recruited only in years with a very high water level during floods. The results of the study of the linear growth indicate the interrelationship between different groups of floodplain–river whitefish from the Maly Patok River basin.
Gudgeon from the Emel River and Problems of the Gudgeon Taxonomy (Genus Gobio, Cyprinidae) in Kazakhstan and Siberia
Authors: Vasil’eva E. D. , Mamilov N. Sh. , Sharakhmetov S. E.
Published: April 2024

A comparative morphological analysis of the gudgeons from the genus Gobio from the collection of the Zoological Museum of Lomonosov Moscow State University enables to describe the gudgeon specimens from the Emel River (Basin of Lake Alakol, south-eastern part of Kazakhstan) as a new species. The new species differs from other gudgeon species distributed in Kazakhstan and neighboring territories by the set of characters and is characterized by a short snout, the length of which is usually less than the postorbital distance; long barbels, usually extending beyond the posterior margin of the eye (always extending beyond the middle of the eye); the absence of scales on the breast, the presence of usually 12 or more black spots along the side, a low body, and a relatively short head. The validity of Gobio latus inhabiting the basin of Lake Issyk-Kul has been restored. The key for diagnosing species of the genus Gobio in Kazakhstan is provided.
Morphological Deformities in Stingrays (Dasyatidae) from the Rameswaram Island, South India
Authors: Yosuva M. , Jeyapragash D. , Tiburtius A. , Jeyabaskaran R. , Rajendran N.
Published: April 2024

The present study reports the deformities in two different species of stingrays Maculabatis bineeshi and Neotrygon kuhlii along the Rameswaram Island. The structural deformity was observed in M. bineeshi species that were collected from Pamban–Therkuvadi fish landing centre, which was the first to be recorded along the Indian coasts with rostral irregularity of the aperture from the anterior margin of the snout around the right margin of the disc from the first gill opening. In addition to the first record, vertebral column deformity was observed in N. kuhlii, which was collected from Kunthukal fish landing centre. The external morphological characteristics showed a curved tail that had vertebral column deformities with severe scoliosis–kyphosis–lordosis starting from the pectoral girdle to the tail region
Peculiarities of Early Ontogeny of Dwarf Forms of Arctic Charr Salvelinus alpinus Сomplex (Salmonidae) from Lakes Tokko and Bol’shoe Leprindo (Transbaikalia). 1. Pure Forms
Authors: Pichugin M. Yu. , Korostelev N. B. , Alekseyev S. S.
Published: April 2024

The results of the study of growth, ossification sequence and peculiarities of the development of skeletal elements, body proportions and meristic characters of laboratory-reared larvae and fry of two dwarf forms of Arctic charr Salvelinus alpinus сomplex spawning at the shore slope (Lake Tokko) and in the profundal zone (Lake Bol’shoe Leprindo) (Transbaikalia) are presented. Charr from Lake Bol’shoe Leprindo demonstrated slower rates of growth and morphogenesis, retardation of the ossification of their predorsal bones series with its displacement from larval to juvenile period of the ontogeny, but the acceleration of the development of the vertebral column. High mortality of pre-larvae of charr from this lake connected with the transfer to exogenous feeding was observed. For the first time the problem of the reorganization of early ontogeny of charr of the genus Salvelinus in connection with the colonization of deepwater habitat is discussed. In larvae of charr from Lake Tokko, the ossification of vertebral centra was often accompanied by the formation of anomalous bony structures in the notochord. The phenomenon of the penetration of skeletogenic cells into the notochord, which has been described in hybrids of sympatric charr forms, was found in a pure charr form for the first time. The development of characteristic morphological features of the two charr forms in the ontogeny was traced. Differences in body proportions between their fry corresponding to those between adult fish were revealed.