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Vol 65, No 5 (2025)
Articles
MORPHOLOGICAL AND GENETIC DIVERSITY OF THE PIDSCHIAN-LIKE WHITEFISH COREGONUS LAVARETUS (SALMONIDAE) IN THE WATER BODIES OF SIBERIA, RUSSIA
Abstract
Whitefishes (Salmonidae: Coregoninae) are important components of the subarctic and subalpine aquatic ecosystems of the Palearctic. In most Siberian Arctic water bodies, they dominate by abundance. The most numerous and morphologically diverse are the pidschian-like whitefishes Coregonus lavaretus sensu lato, among which several forms/species with an unclear taxonomic status have been described. Most of the morphologically significantly different forms/species of whitefish live on the periphery of the entire range of the whitefish species. In most cases, genetic analysis of whitefish allows us to clarify the taxonomic status of disputed species and to analyze their phylogenetic relationships. However, there are cases when the results of morphological and genetic studies contradict each other, so additional methods of analysis are necessary. In our work, we attempted to analyze the issues of origin and differentiation of some of the most taxonomically complex forms/species of whitefish based on modern morphological and genetic methods of analysis.
Journal of Ichthyology. 2025;65(5):511-530
511-530
NEW DATA ON THE MORPHOLOGY OF MYOXOCEPHALUS SCORPIOIDES (COTTIDAE) FROM THE CHAUN BAY OF THE EAST SIBERIAN SEA AND ANALYSIS OF THE VARIABILITY OF SOME DIAGNOSTIC CHARACTERS OF THE SPECIES
Abstract
This paper presents a morphological description of Myoxocephalus scorpioides from the Chaun Bay of the East Siberian Sea. A comparative analysis of the studied individuals with representatives of the species from the Bering Sea, as well as with the literature data on a combined sample of M. scorpioides from the Chukchi Sea and Bering Strait, has revealed a geographical variability of morphometric characters and a high degree of stability of a number of meristic characters (number of rays in the 1st dorsal fin and anal fin and total number of vertebrae). The significance of some taxonomic characters has been clarified. It is shown that characteristics such as the absence of postorbital and occipital tubercles, the presence of barbels in their place, the presence of bone plaques on the sides of the body, and the lengths of the upper and lower jaws, can be used for taxonomic purposes with high reliability.
Journal of Ichthyology. 2025;65(5):531-541
531-541
GENETIC VARIABILITY AND RELATIONSHIPS OF THE THREADED SCULPIN GYMNOCANTHUS PISTILLIGER (COTTIDAE)
Abstract
Comparative molecular genetics study was performed for the threaded sculpin Gymnocanthus pistilliger from the Sea of Okhotsk, the Sea of Japan, and the Bering Sea. According to the analysis of mitochondrial DNA genes, the species heterogeneity is found, which does not relate to its geographical distribution. Gymnocanthus pistilliger is characterized by a closely related relationship with Gymnocanthus intermedius, the genetic differentiation between these species is low if considering them different species. The analysis of the obtained results in molecular genetics and morphological data published by other authors, suggest that G. pistilliger and G. intermedius represent either geographical forms (subspecies) of the same species, or evolutionarily young species.
Journal of Ichthyology. 2025;65(5):542–556
542–556
ZOOGEOGRAPHICAL ZONING OF NORTHERN EUROPEAN RUSSIA BY THE COMPOSITION OF FRESHWATER ICHTHYOFAUNA
Abstract
Zoogeographic changes in the composition of the ichthyofauna of large rivers in northern European Russia have been clarified. A characteristic feature of the studied region is a significant number of fish species of the cold-water complex: Salmoninae, Coregoninae, Thymallinae and Osmeridae. The proportion of different fish groups in the ichthyofauna of the river basins changes significantly in the direction from west to east. The proportion of Salmoniformes, representatives of the cold–water complex, increases, while that of Cypriniformes decreases. The number of families from other orders, represented by a much smaller number of species, remains almost unchanged. The Pechora River basin is transboundary, and the interpenetration of the European and Asian ichthyofauna occurs through it. According to the degree of faunal similarity, the basins of the Onega, Northern Divina and Mezen rivers are closer to the Western zoogeographic subdistrict with a predominance of fish of the Baltic complex; Volonga, Pechora and Kara are closer to the Eastern subcircle with a predominance of fish of the Siberian complex. According to the degree of faunal similarity, the basins of the Onega, Northern Divina and Mezen rivers are closer to the Western zoogeographic subdistrict with a predominance of fish of the Baltic complex; the basins of the Volonga, Pechora and Kara rivers are closer to the Eastern subdistrict with a predominance of fish of the Siberian complex. The conditional boundary between the two groups runs along the basin of the Volonga River, in which the proportions of European and Siberian species are the same. In the zoogeographic zoning of the territory of the north of northern European Russia, it is proposed to subdivide the Eastern subdistrict into Severodvinsk and Pechora areas, with Severodvinsk and Mezen subareas in the first, and Pechora and Kara subareas in the second.
Journal of Ichthyology. 2025;65(5):557-575
557-575
DISTRIBUTION AND SOME ASPECTS OF BIOLOGY OF LYCODES CF. BRASHNIKOVI (ZOARCIDAE) WITH NOTES ON THE SPECIES COMPOSITION OF GENUS LYCODES OFF THE PACIFIC COAST OF KAMCHATKA
Abstract
Based on the results of bottom trawl surveys, the distribution and some aspects of biology of Lycodes cf. brashnikovi Soldatov, 1918 off the Pacific coast of Kamchatka are considered. In summer, main accumulations of this species are noted in Kronotsky Bay, and are rare to the south from 52° N. The bathymetric range of occurrence of the species is 83–202 m; the largest catches are typical for the depths of 100–180 m. The maximum length of L. cf. brashnikovi in Pacific waters is 53 cm, weight, 554 g. According to the degree of maturation of the gonads in summer, the species reproduces in the autumn–winter period. Critical analysis of the literature and original data, currently the genus Lycodes off the Pacific coast of Kamchatka is represented by five species, among L. cf. brashnikovi is the most abundance species in the cultural zone.
Journal of Ichthyology. 2025;65(5):576-589
576-589
BIOLOGICAL PARAMETERS OF TRACHURUS MEDITERRANEUS (CARANGIDAE) OFF THE COAST NEAR SOUTHWESTERN CRIMEA DURING THE PERIOD FROM 2020 TO 2022
Abstract
This paper presents the results of a study of the sex and size—age structure, growth, maturation, and dynamics of the gonadosomatic index and condition factor of Mediterranean horse mackerel Trachurus mediterraneus (Steindachner, 1868) in the coastal waters of the Black Sea off southwestern Crimea in 2020–2022. A total of 2234 specimens have been studied, 879 of them being sexed. The male-to-female ratio (1.00:1.02) in the catches did not statistically differ from 1:1; no differences in growth rates have been found between the sexes. The maximum total body length is 26.1 cm for an individual aged 8+. Parameters of the von Bertalanffy equation for the whole sample were as follows: asymptotic length, 21.9 cm, asymptotic weight, 86.3 g, and growth constant, 0.24 year-1. Fifty percent of females mature at a total body length of 12.43 cm at age 1+ and 50% of males at a total body length of 12.46 cm at the same age. The peak of the spawning period is observed in July and the peak values of the condition factor in November.
Journal of Ichthyology. 2025;65(5):590–604
590–604
DURATION OF EMBRYONIC AND LARVAL DEVELOPMENT OF CHUM SALMON ONCORHYNCHUS KETA (SALMONIDAE) ON SAKHALIN AND ITURUP ISLANDS
Abstract
The duration of embryonic and larval development of chum salmon Oncorhynchus keta under different temperature conditions was studied based on long-term data on the species breeding at three salmon hatcheries on the southeastern coast of Sakhalin Island and at three hatcheries on Iturup Island. The temperature conditions at each of them depended on the water supply system. The obtained results are fully consistent with the well-known general pattern of a slowdown in the development rate of Pacific salmons with a decrease in water temperature. At the same time, when comparing the corresponding data on salmon hatcheries from different regions, statistically significant differences were found both in the duration of embryonic–larval development of chum salmon in connection with water temperature (parallelism of regression lines) and in the rate of yolk resorption in larvae at similar temperatures. Despite the specific conditions of hatchery breeding, the revealed differences are quite explainable by the peculiarities of natural reproduction of the studied chum salmon groups. The results suggest a hereditary basis for the rate of embryonic and larval development of chum salmon, the genetic differences of which between the studied areas were previously identified. Consequently, differences in the development rates of chum salmon offspring during the freshwater period of life can serve as another criterion in addition to morphological, biological and genetic differences, on the basis of which ecogeographic units of the species are distinguished.
Journal of Ichthyology. 2025;65(5):605–617
605–617
INFLUENCE OF TEMPERATURE ON SPONTANEOUS LOCOMOTOR ACTIVITY OF THE SADDLER BICHIR POLYPTERUS ENDLICHERII (POLYPTERIDAE)
Abstract
Using the open field method, the spontaneous locomotor activity of the saddler bichir Polypterus endlicherii has been estimated at different water temperatures (20, 25, 30, and 34°C). The locomotor activity of the fish increases by 1.40 times in the temperature range of 20–25°C (temperature coefficient 2.1); more strongly (2.00 times) it increases in the temperature range of 25–30°C (4.1), while in the range of 30–34°C (1.1) it changes insignificantly (1.04 times). With an increase in temperature, the swimming speed and the distance covered by the fish in one hour increase; subsequently, the time spent on crossing the test line decreases. The coefficient of variation of the locomotor activity indices decreases with an increase in temperature. Comparison with the previously studied Senegal bichir P. senegalus revealed both similarities and differences in the locomotor activity of these two sympatric species.
Journal of Ichthyology. 2025;65(5):618-624
618-624
HISTOLOGICAL STRUCTURE OF LIVER, TRUNK KIDNEY AND SPLEEN OF THE ALTAI OSMAN OREOLEUCISCUS POTANINI (CYPRINIDAE) FROM THE ISOLATED POPULATION OF LAKE KIDELYU (ALTAI REPUBLIC, RUSSIA)
Abstract
For the first time, histological structure and morphometric indices of the liver, trunk kidney and spleen of the Altai osman Oreoleuciscus potanini (Kessler, 1879) are presented. The liver parenchyma has hepatocyte-sinusoidal cord-shaped structure. The biliary structures are presented by isolated and biliary-venous. The sections of the nephron of the trunk kidney (proximal and distal tubules) and collecting tubules were morphologically clearly distinguished by the area of the nucleus and the height of the epithelium, the development of the brush border (limbus strigillatus) and the thickness of the basal membrane. The spleen structure is presented by connective tissue trabeculae representing the organ stroma. Fuzzy boundaries are noticeable between the red and white pulp, the volume fraction of the white pulp (55.98%) is higher than that of the red pulp (37.82%). Pathological changes in the liver (inflammation near the bile ducts, foci of vacuolization, expansion of the liver sinusoids, foci of cells with signs of pycnosis) were insignificant, both by distribution and degree of development. In the kidneys of some individuals, localized foci of inflammation and degradation of the renal tubules were detected. In the future, the described morphological features of the histological structure of the liver, trunk kidney and spleen of the Altai osman will allow to conduct monitoring studies aimed at assessing the state of populations of endemic fish species in the reservoirs of the Altai Mountains, and to deepen the understanding of the morphology and histology of carp-like fish (Cypriniformes).
Journal of Ichthyology. 2025;65(5):625–639
625–639
КРАТКИЕ СООБЩЕНИЯ
FINDING OF THE PEACOCK BLENNY SALARIA PAVO (BLENNIDAE) IN THE KERCH STRAIT (CRIMEAN PENINSULA) AND SOME OF ITS ECOLOGICAL AND BEHAVIORAL FEATURES
Abstract
Information is provided on the finding of the peacock blenny Salaria pavo (Blenniidae) in the Kerch Strait (Crimean Peninsula), where it had not previously been recorded. The ecological and behavioral features of individuals of this species in a new area of its habitat are described. The probable reason for the expansion of the range of peacock blenny in the northern direction in the Azov-Black Sea basin is the increase in winter temperatures in the Kerch Strait, resulting in favorable conditions for wintering of the species.
Journal of Ichthyology. 2025;65(5):640–644
640–644