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Vol 18, No 2 (2025)
CТРУКТУРА И ФУНКЦИОНИРОВАНИЕ ВОДНЫХ ЭКОСИСТЕМ
The structure of communities of hydrobionts in the eastern compartment of the Proletarsky reservoir (Don river basin)
Abstract
In October 2022, hydrological, hydrochemical parameters, structural characteristics of phyto-, zooplankton and macrozoobenthos were studied in the western part of the eastern compartment of the Proletarian Reservoir, which has a specific thermohaline structure. In the water area under investigation, three regions were identified based on water mineralization values (from 1.1 to 81 g/l): eastern, lake (highly mineralized up to 81 g/l); central (mixing zone) and western (fresh). Among the aquatic organisms, euryhaline and halophilic species predominated. In the conditions of a mineralization wide range in these areas, differences in the structure of communities and their quantitative indicators were noted, which are associated with the presence of an unstable lateral gradient of water mineralization, depending on the strength, direction of the wind and the amount of fresh water entering through the Novo-Manych Dam.
Inland Water Biology. 2025;18(2):247-259
247-259
БИОЛОГИЯ, МОРФОЛОГИЯ И СИСТЕМАТИКА ГИДРОБИОНТОВ
New molecular and phenotypic data on Encyonema simile (Bacillariophyceae)
Abstract
Encyonema simile Krammer is a rare species, known from only six locations worldwide. A clone of this species was isolated from a waterlogged soil sample collected in June 2021 in the Zabelovsky cluster, Bastak State Nature Reserve (Jewish Autonomous Region, Russia) and identified using light and scanning electron microscopy. Phylogenetic analysis based on rbcL gene sequence comparison showed that the clone belongs to the genus Encyonema. Vegetative cell enlargement was described for E. simile for the first time, which is the first mention of this process in the genus Encyonema. As a result of the study the information on the phenotype (the upper limit of cell length, the number of striae and areolae in 10 μm, the structure of the cingulum) was supplemented and the first molecular data were obtained.
Inland Water Biology. 2025;18(2):260-268
260-268
The stability of the morphological characteristics of the semi-aquatic plant Phragmites altissimus Mabille (Poaceae) that is alien to the forest zone of Eurasia
Abstract
The discussion about the composition of the reed genus (Phragmites) and the nomenclature of individual reed taxa is still open. One of the most pressing questions is the taxonomic status of the highest reed (P. altissimus) due to its high invasive activity, recently noted in the forest zone of Eurasia. Many authors consider this species as a part of closely related the common reed (P. australis). In this regard, the purpose of our research was to prove the species independence of the highest reed using comparative morphological analysis. We showed that two closely related species, P. australis and P. altissimus, have statistically significant differences in such studied morphometric parameters as height of reproductive shoots, number of nodes on shoot, diameter of stem in the lower and upper parts of shoot, length and width of middle leaves, as well as raw above ground shoot biomass. We also found that P. altissimus stably retains morphological features in the forest zone of northern Eurasia and, according to the studied parameters, does not differ from P. altissimus from the region of the species' primary range, except for such an indicator as the number of nodes on reproductive shoot. This indicator is significantly higher in plants from the primary area compared to plants from the zone of invasion. The obtained results confirm the species independence of P. altissimus that retains its species-specific features within the entire modern species range.
Inland Water Biology. 2025;18(2):269-281
269-281
ФИТОПЛАНКТОН, ФИТОБЕНТОС, ФИТОПЕРИФИТОН
Features of the phytoplankton distribution in Lake Sevan (Armenia) in summer and autumn 2019
Abstract
The species composition, features of spatial distribution and diurnal dynamics of phytoplankton in Lake Sevan in summer and autumn under the influence of abiotic and biotic factors were studied. In the summer of 2019, low phytoplankton biomass was observed in Lake Sevan. Green algae dominated in biomass. The autumn biomass of plankton algae was significantly higher than the summer one, diatoms dominated, and the potentially toxic Cyanoprokaryota Nodularia spumigena was a subdominant. The highest biomass of phytoplankton was observed in the surface horizon, but at some stations deep maxima of biomass of some orders were noted. High zooplankton pressure was noted in the metalimnion, where the minimum total biomass of phytoplankton, the biomass of cyanoprokaryotes, green and diatom algae, were recorded in summer.
Inland Water Biology. 2025;18(2):282-291
282-291
Phytoplankton of the Neva Bay and the Inner Estuary of the Gulf of Finland in 2001–2020
Abstract
In 2001–2010 in the Neva Bay, as before, as from the beginning of the research (1980), the phytoplankton of the southern zone remained the richest, most diverse and highly productive. In the second decade, starting from 2014–2015 in the summer period, the indicators of phytoplankton biomass, in the northwestern zone of the bay increased sharply. In the inner estuary of the Gulf of Finland in late July – early August, conditions are created for the development of planktonic algae in the epilimnion with a predominance of cyanobacteria capable of causing water bloom. The most significantly quantitatively changing phytoplankton species during the study period were the cyanobacteria Planktothrix agardhii and the diatoms Skeletonema subsalsum. In the second decade of the studies, the biomass of phytoplankton in the summer was about 7 mg/L everywhere. Eutrophication observed in the estuary is provided by both anthropogenic and natural climatic factors.
Inland Water Biology. 2025;18(2):292-297
292-297
ВЫСШАЯ ВОДНАЯ РАСТИТЕЛЬНОСТЬ
Macrophyte phytomass and production in lakes of Belorussian Lakeland
Abstract
Information on the production characteristics of aquatic vegetation species in the lakes of the Belarusian Lakeland is summarized. For 43 different representatives, data are provided on the values of phytomass, air-dry weight, productivity, and number of specimens depending on the classes of projective cover. The values of phytomass and air-dry weight parameters obtained for the Belarusian Lakeland are within the ranges of values given for other natural territories of the Republic of Belarus. The values of phytomass of macrophytes of the Belarusian Lakeland were also compared with data for other regions, and the closest similarity of the indicators of the surveyed territory with data for the Komi Republic, Upper Volga region, north-west Russia and the Republic of Buryatia was established. The indicators of phytomass, projective cover and number of plants per square meter of 16 species in different lake’s types were analyzed and significant differences were received for Phragmites australis, Nuphar lutea, Potamogeton lucens, Persicaria amphibia, Equisetum fluviatile, Schoenoplectus lacustris. For 20 out of 28 species, reliable significant or high values of correlation and regression coefficients were established for the interconnection of phytomass indicators with the parameters of projective cover and (or) abundance per square meter.
Inland Water Biology. 2025;18(2):298-311
298-311
ЗООПЛАНКТОН, ЗООБЕНТОС, ЗООПЕРИФИТОН
Features of the structure of macrozoobenthos of watercourses in the conditions of an intact, heavily swamped area – the basin of Lake Vodlozero and the Vodla River (Vodlozersky National Park, Lake Onega basin)
Abstract
The features of the composition, diversity, abundance and trophic structure of macrozoobenthos in nine rivers of the Vodlozersky National Park and its buffer zone (Ileksa, Verkhnyaya Okhtoma, Novguda, Kelka, Okhtoma, Sukhaya Vodla, Vama, Lepruchey, Vodla) were analyzed. A total of 17 stations were surveyed in the summer of 2019 and 2022. Vodlozersky Park is one of the largest untouched areas in Europe, characterized by high swampiness and low-mineralized, highly colored waters. In the macrozoobenthos of rivers, chironomid larvae are the leaders in abundance. Along with them, there are numerous caddisflies on boulder-pebble soils, oligochaetes on sandy soils and bivalves on silt-clay-detritus soils. The areas located at the source of the lake are particularly abundant. The greatest α-diversity was observed in the biotope of boulder-pebble soils. The differences between biotopes in the ratio of trophic groups lie in the predominance of collectors-filters in fast flows and collectors-gatherers in slow flows.
Inland Water Biology. 2025;18(2):312-320
312-320
ИХТИОЛОГИЯ
Fishes of the Salgir River in modern realities: anthropogenic impact and invasive species
Abstract
The fish fauna of small mountain and foothill rivers of Crimea is currently undergoing significant changes. The main factors determining these processes are the penetration of alien species, active exploitation of rivers by humans, and modification of the Crimean hydrographic network associated with the North Crimean Canal. All this necessitated an assessment of the current state of the Salgir River ichthyofauna. In the period from 2010 to 2014 and in 2023, 2465 fish specimens were sampled in four areas of the river. A decrease in species diversity was revealed, especially pronounced in the upper reaches of the Salgir River (from 11 to 7 species), where the invasive species Alburnoides maculatus (Kessler, 1859) was a stable superdominant. The share of other alien species also increased from 1.5 to 13.1%. In the transition area between the upper and middle reaches of the Salgir River, extremely low numbers and diversity of fish communities have been recorded. A change in the species composition was noted here: the previously common minnow Phoxinus phoxinus (L., 1758) (70%) was replaced by the chub Squalius cephalus (L., 1758) and the gudgeon Gobio krymensis Bănărescu & Nalbant, 1973. Invasive species were occasionally encountered – the pumpkinseed Lepomis gibbosus (L., 1758) (25.0%) and the bleak Alburnus alburnus (L., 1758) (1.95%), but the previously common shemaya A. mentoides Kessler, 1859 and the Crimean barbel Barbus tauricus Kessler, 1877 were absent. The elimination of the rheophilic native species – the stone loach Barbatula barbatula (L., 1758) – was recorded. In the direction from the upper to the lower reaches of the river, the indices of species richness and evenness increased, and the dominance index decreased. An improvement in the diversity of fish population in the lower reaches of the river was noted, but it should be taken into account that they are represented mainly by alien species, the proportion of which varied from 80.9 to 98.7% (on average 89%).
Inland Water Biology. 2025;18(2):321-329
321-329
Reproductive characteristics of pike Esox lucius (Esocidae) of the Kama reservoir (Perm krai)
Abstract
The pike Esox lucius (L., 1758) is an apex predator important for commercial and recreational fisheries in Eurasia and North America, and aspects of its reproductive biology remain mainly unstudied. Based on materials collected in 2016–2023, we have studied the ontogenetic, interannual and geographic variability of sex-age composition, absolute (AF) and relative (RF) fecundity, gonadosomatic index and egg diameter of pike in the Kama Reservoir. The spawning requirements were also investigated. The individuals from three-year old to 16 years old were used in the study. The results of the study showed the high importance of plant substrate for spawning of the species. In years with early spring, pike spawning occurred extremely late at 14–19°C only after the water level had risen, providing access of adults to spawning substrate. The values of AF of the pike of the Kama reservoir corresponds to fish from the southern part of the species' range. In terms of RF, pike in the Kama reservoir occupy an intermediate position between the northern and southern populations. In contrast to AF, which constantly increase with age, RF and GSI (gonadosomatic index) of pike in the Kama Reservoir increase in fish up to 8 years of age. In older individuals, a decrease in these indices were observed. The results of the studies may indicate that the most favorable conditions for pike habitat are formed in the central part of the reservoir, which is characterized by the largest area of shallow habitats, as evidenced by the maximum values of AF and RF, as well as reduced mortality of males. At the same time, under conditions of negative climatic anomaly, despite large linear growths, pike from the central part of the reservoir were characterized by lower condition factor, as well as GSI, AF and RF, which may be determined by a greater amplitude of water temperature fluctuations in shallow habitats under adverse weather conditions.
Inland Water Biology. 2025;18(2):330-345
330-345
Rate of change in COX1 mitochondrial DNA, behavior and body size of the roach Rutilus rutilus, bream Abramis brama and their reciprocal hybrids
Abstract
Variability of the mitochondrial cytochrome c-oxidase I (mtDNA) gene fragment is negatively associated with body size of roach Rutilus rutilus (L., 1758), and bream Abramis brama (L., 1758), and is the cause of intergenomic conflict in hybrids with of highly polymorphic mtDNA of roach. Different aerobic requirements due to differences in body size between roach and bream may have increase the selection of co-adapted mitochondrial-nuclear genes for ATP production and led to divergence of species in locomotor activity and neural processes. These differences may be related to the rate of free radical leakage (ROS), which is set by the apoptotic threshold and is linearly related to the rate of change in COX1. The roach has a smaller body size, higher motor and feeding activity, and a low threshold of excitability, which determines the interspecies differences of behavioral reactions with bream without a predator and in the presence of a low-active predator. The high rate of changes in COX1 and ROS leakage in roach allow to tolerate the suboptimal correspondence of mitochondrial-nuclear respiratory complexes for ATP production and to reduce the threshold of excitability of the nervous system. Intergenomic conflict, which manifests itself in hybrids ♀R. rutilus × ♂A. brama by a violation of the inheritance of greater body length from the male bream, does not affect the maternal effect of behavioral traits. Whereas high genomic compatibility leads to an increase in boldness (ROS threshold), the strength of the excitatory process, and the similarity of hybrids ♀A. brama × ♂R. rutilus with the male roach in terms of motor activity, which may be a consequence of remodeling of energy metabolism due to the inheritance of the roach body length. However, under stress conditions, the curve of the dynamics of the behavior of AR hybrids is similar to A. brama, but hybrids can no longer quickly reduce the metabolic rate to zero, like bream.
Inland Water Biology. 2025;18(2):346-358
346-358
ПАРАЗИТОЛОГИЯ ГИДРОБИОНТОВ
Similarity in Parasitic Metazoa Fauna Between Two Sympatric Grayling Species (Salmonidae) in Two Bays of Lake Baikal
Abstract
A comparative analysis of the fauna of parasitic Metazoa of two sympatric grayling species, the black Baikal one and the white Baikal one, from the Chivyrkuisky and Barguzinsky Bays of Lake Baikal was carried out. The level of similarity in the species composition of parasitic Metazoa between the black and white grayling in Chivyrkuisky Bay is the largest among all pairs of host groups, in Barguzinsky one – minimal, half as much, which is due to the characteristic features of the second Bay.
Inland Water Biology. 2025;18(2):359-366
359-366
ЭКОЛОГИЧЕСКАЯ ФИЗИОЛОГИЯ И БИОХИМИЯ ГИДРОБИОНТОВ
The Influence of Nutritional Spectra on the Fatty Acid Composition of Muscle Tissue and on Omega-3 PUFA Content in the Brain, Muscle and Adipose Tissues of Fish of the Genus Thymallus.
Abstract
In human nutrition, fish is a primary source of physiologically valuable polyunsaturated fatty acids (PUFAs) of the omega-3 family: eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The content of these PUFAs in the biomass of different fish species varies significantly. Differences in the content of EPA and DHA at the higher taxonomic levels (order, family) are associated with phylogenetic factors, while intraspecific variations are linked to the spectrum of diet. However, the impact of these factors on PUFA content in lower taxonomic ranks (genus) remains understudied. This study focused on three species of grayling from nine water bodies. Thymallus baicalensis was collected from the Yenisei, Angara, Mana, Bazaikha, Gladkaya Kacha, Krutaya Kacha, and Tamasul rivers; T. thymallus from the Sylva River, and T. arcticus from Lake Sobachye. Fish diets were determined based on the fatty acid composition of their adipose tissue and stomach contents. The research revealed that the diet had a more significant influence on the fatty acid composition of grayling muscle tissue than the taxonomic position of the fish. The absolute content of physiologically valuable EPA and DHA in muscle tissue depended on the diet, ranging from 2.3 mg/g wet weight in fish with a high proportion of allochthonous organic matter in their diet to 6.5 mg/g wet weight in fish whose diet consisted exclusively of autochthonous organic sources. The impact of fish diet on the EPA and DHA content in the brain tissue was negligible. Among the studied tissues, adipose tissue was the leader in EPA+DHA content (35.8–120.3 mg/g wet weight), surpassing the content of these PUFAs in muscle tissue by 15–31 times. Thus, the nutritional value of grayling for human consumption, assessed based on the EPA and DHA content, varied threefold.
Inland Water Biology. 2025;18(2):367-380
367-380
ВОДНАЯ ТОКСИКОЛОГИЯ
Features of the accumulation of heavy metals by macrophyte algae of salt lakes in the Transbaikal territory
Abstract
Among the currently known pollutants, heavy metals (TM) are of particular concern. A study of the content of TM in water and macroalgae in the salt lakes of the south-east of the Transbaikalia Territory, which do not experience pollution from industrial enterprises, was carried out. The aim was to study the features of the accumulation of heavy metals in soda and sulfate-type lakes. The studied rivers and lakes differ in mineralization (from 0.45 to 45.29 g/dm3) and pH (from 7.80 to 9.55). With the increase in water mineralization, the contents of the main ions increase, with the exception of calcium, and the chemical type of HCO3 Ca–Mg changes to HCO3 Na–Mg. A similar pattern, but with a more pronounced salinization process, is noted for soda lakes. The value of mineralization and pH in the waters of soda lakes is higher than that of river lakes. The sulfate type differs from soda by a higher mineralization of water, but a lower pH value. With increasing salinity, CO32- and HCO3- do not accumulate Cladophora fracta, Enteromorpha intestinalis, Stigeoclonium flagelliferum, Spirogyra sp. ster., Rhizoclonium riparium. The rivers and lakes of this area have low concentrations of most heavy metals. The maximum number of them is determined in a saltier lake with an oxidizing environment Barun-Shivertui. A comparative assessment of the content of TM in macroalgae of salt lakes with macroalgae of fresh and marine waters showed comparability with their clarks, therefore, the concentrations obtained will be background for salty reservoirs of the south-east of Transbaikalia. Macroalgae accumulated less metal in total with increasing salinity, but reacted differently to the pH of the water. In soda reservoirs, with an increase in pH, the total value of the accumulation coefficient decreased, while in sulfate reservoirs, on the contrary, it increased. The linear dependence of the values of the TM accumulation coefficient in macroalgae containing Men+ in water and with positively charged complex ions MeCl+, MeHCO3+ indicates the possibility of their assimilation by plants. At the same time, the established inverse dependence of KN TM in plants with FA-Me, Me(OH)3, MeCO3, AsO43- indicates a negative effect of these complexes on the bioavailability of metals.
Inland Water Biology. 2025;18(2):381-392
381-392
The effect of low doses of mercury on the temperature tolerance of juvenile carp Cyprinus carpio
Abstract
The effect of supplied with food mercury on the temperature tolerance of juvenile carp Cyprinus carpio L. data were obtained for the first time in a chronic experiment. The total mercury content in the fish feeds of the two experimental groups was 0.02 mg/kg and 0.27 mg/kg of crude weight. After 5 months of the experiment, the mercury content in the muscles of fish fed with a higher concentration of mercury increased by 26 times, and from a lower concentration – by 5 times. The temperature tolerance of juvenile carp was determined monthly using the method of critical thermal maximum and the method of chronic lethal maximum. The accumulation of mercury in muscles up to 1.82 mg/kg did not have a significant (p >0.05) effect on the studied temperature characteristics of carp both under conditions of rapid (~8°C/h) and slow (1°C/day) water heating. The average values of KTM were 35.8–36.1°C, CLM – 39.6–39.7°C in fish of all experimental groups. At the same time, slow heating (the HLM method) contributed to accelerated accumulation of mercury in the muscles of fish receiving both low and increased doses of mercury. Apparently, the level of accumulated mercury did not cause significant failures in the operation of systems that ensure the temperature stability of the body. At the same time, the increased temperature background led to a significant acceleration of its accumulation.
Inland Water Biology. 2025;18(2):393-400
393-400