The article presents the results of the study of the activity of key enzymes of energy and carbohydrate metabolism in pink salmon Oncorhynchus gorbuscha spawners during spawning migration from the estuary to the river. A decrease in the activity of carbohydrate metabolism enzymes (lactate dehydrogenase and pyruvate kinase), 1-glycerophosphate dehydrogenase in red muscles and...
Fish distribution in different areas of Bratsk Reservoir has been studied using hydroacoustic equipment. The average abundance of fish decreases (r = –0.70; p < 0.05; R2 = 0.49) from the near-dam reach (214 ± 34 ind./ha) to the water area in the upper reaches of the reservoir (113 ± 43 ind./ha). A similar relationship is observed in the dynamics of the abundance of early...
The results of the study of local populations of the resident form of the European river lamprey Lampetra fluviatilis in medium and small watercourses (tributaries of the Pola and Msta rivers), located at a distance of ~700 km from the sea, in the native part of the species range, are presented. Such populations are still poorly studied, despite the fact that they ensure the...
Macro- and microscopic studies of the state of the gonads of spawners of whitespotted char Salvelinus leucomaenis, Dolly Varden S. malma, and whitespotted char × Dolly Varden hybrids from the Utkholok River (northwestern Kamchatka) in the post-spawning period have revealed no anomalies in the structure of the gonads and their cytological state. The generative tissue of the testes...
Environmental and ecological effects of the dam of the high-pressure Bratsk Hydroelectric Power Station (HPS) on the fish population and the probability of fish downstream migration from the Bratsk Reservoir have been studied. It has been revealed that thermal stratification of the water column is a significant factor in the ecological differentiation of the fish population in...
Numerous studies show that species identification of representatives of the genus Alosa using various genetic markers is often difficult and the search for more specific biomarkers is required. For the first time we analyzed polymorphism of COI gene fragment of mitochondrial DNA of two representatives of this genus (A. tanaica and A. kessleri), supplemented with new data on A...
The reproductive and phylogenetic relationships of lenoks of the genus Brachymystax are considered based on analysis of 30 allozyme loci and two fragments (411 and 987 base pairs) of the mitochondrial DNA control region. The presence of three phylogenetic lenok groups, the blunt-snouted and sharp-snouted groups from Russia and neighboring countries and the Qinling group from...
The outcomes from the survey research in distribution of the giant grenadier Coryphaenoides pectoralis at different stages of development in the Northwest Bering Sea over 1963–2020 have been reported. The data for 37 thousand catches performed with the bottom and multi-depth trawls at the depths between 0–1200 m are processed. It has been revealed that the species fish tend to...
Individual movement parameters for the zebrafish Danio rerio and the Prussian carp Carassius gibelio during starvation for 12 days have been determined in an experimental hydrodynamic installation circular tank. The fishes represent two tactics of behavioral responses on starvation. The tactics of unidirectional responses have been manifested in the movement of individuals in one...
The study of diversity in characters of the skull in generalized and specialized morphotypes of the large African barbs Barbus (Labeobarbus auctorum) in Ethiopia is carried out using the multivariate analysis methods. It has been proven that in Lake Tana exhibiting great diversity in morphotypes, the eigenvector loadings on the first principal component of characters of bones...
An isolate tooth of a rare extinct hook-toothed mako Cosmopolitodus planus (Agassiz, 1856), discovered in the Lower Miocene deposits of the Chekhov Formation of Sakhalin Island is described. This extinct species was distributed exceptionally in the Pacific basin, and is known mainly from the deposits of the Middle and Upper Miocene. Thus, the described tooth is, probably, the...
Small freshwater (resident) populations of the European river lamprey Lampetra fluviatilis from an isolated from the sea upper part of a river system with numerous lakes (the upper reaches of tributaries of the Daugava River and Lake Peipus, Pskov Oblast, Russia) have been studied. Adult individuals of the lamprey have been attributed to common and large size groups; adults are...
For the first time the qualitative and quantitative lipid profile (total lipids and polar and nonpolar lipids) of the muscle tissue of six mesopelagic fish species, which are representatives of two deep-sea families widespread in the World Ocean: Stomiidae and Myctophidae were studied. It was found the species specificity of lipid accumulation for the studied fishes, which...
The data for a 23-year period (2000–2022) on the population dynamics and distribution of the lake smelt (a form of the European smelt Osmerus eperlanus) and the Black Sea sprat Clupeonella cultriventris in the Rybinsk Reservoir have been summarized. The lake smelt dominated the reservoir pelagial from the 1950s to the mid-1990s. An anomalously low water level in the reservoir in...
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...
We have analyzed the polymorphism of ISSR fragments of DNA by polymerase chain reaction in spined loaches for the first time. The analysis has made it possible to successfully differentiate the genomes, which were presumably involved in the formation of polyploid forms of hybrid origin: Cobitis taenia; spined loaches from the Danube River basin, which are diagnosed as C...
Analysis of the structure of the morphological diversity of the Altai osmans of the genus Oreoleuciscus in the Urt River (water system of the Tes River) indicates that this is a polymorphic population, consisting of three forms, clearly differentiated by a set of characters. The ratio of differences between these forms and forms previously identified in the Zavkhan (water system...
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...
The results of previous studies on the population structure of the sockeye salmon Oncorhynchus nerka of Western Kamchatka are revised based on the analysis of the variability of 45 single nucleotide polymorphism loci using both own data (seven samples from the water bodies of the western coast of the Kamchatka peninsula) and the data obtained by other researchers (seven samples...
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...
The NetCor research hydroacoustic system has been used to study the anadromous migration of the rainbow trout Parasalmo mykiss (Walbaum, 1792) in the Kvachina River (Western Kamchatka) during its autumn entry from the sea. The intensity of the fish movement increases in similar periods of the neighboring years (2010–2011), which indicates the cyclical migration of the species...