No 1 (2023)

The fauna of caddisflies was studied from two protected areas of federal significance such as Mordovia State Nature Reserve (Temnikov district, Republic of Mordovia) and National Park “Smolny” (Ichalki district and Bolshoe Ignatovo district, Republic of Mordovia). The material was collected from May to October 2008, 2009, 2013–2021. There were 677 specimens from 59 caddisfly species from 12 families. The largest family Limnephilidae includes 29 species, there were 9 species each in the families Phryganeidae and Leptoceridae. Limnephilus sericeus and Holocentropus dubius dominated in the collections (12 and 10% from the total amount respectively), Hydropsyche angustipennis (8.9%), Hagenella clathrata (8.7%), Phryganea grandis (7.5%), Hydropsyche pellucidula (7.1%), Halesus tesselatus (6.6%) were numerous. Eighteen species of caddisflies (Rhyacophila fasciata, Holocentropus dubius, Agrypnia varia, Oligostomis reticulata, Anabolia concentrica, Anabolia furcata, Chaetopteryx villosa, Halesus digitatus, Limnephilus binotatus, Limnephilus extracatus, Limnephilus fuscicornis, Limnephilus ignavus, Limnephilus sericeus, Limnephilus sparsus, Limnephilus vittatus, Micropterna lateralis, Molanna albicans, Ceraclea excisa) supplement the known information on the fauna of the Republic of Mordovia, where 73 species from 14 families are currently recorded. The species Molanna albicans is indicated for the first time for the fauna of the Middle Volga region. Non-metric multidimensional scaling analysis revealed similarities and differences in the composition of trichopterofauna among the study sites. There was the maximum similarity among the sites with more diverse biotopes. There were indicated preferred habitats of some species.

The abundance, biomass, size-morphological structure, growth rate and production of bacterioplankton, the intensity of primary phytoplankton production and dark fixation of CO₂, as well as the abundance and biomass of heterotrophic nanoflagellates were determined in a large plain eutrophic reservoir (Gorky Reservoir, Middle Volga). The abundance, biomass, and production of bacterioplankton were relatively high and averaged 7.6 × 10⁶ cells/mL, 117.9 mg C/m³, and 59.2 mg C/(m³ × day), respectively. Heterotrophic nanoflagellates reached a high level of quantitative development – 6.9 × 10³ cells/mL, 47.9 mg C/m³. Their biomass averaged 41.6 ± 18.4% of the bacterioplankton biomass, which indicates that, in addition to bacteria, nanoflagellates used other food sources. Small rods and cocci dominated among the size-morphological bacterioplankton groups and accounted for 36.3 and 33.3% of its total abundance, respectively. Small rods averaged more than a half (56.2%) of the total biomass and were the most stable component of the community. The growth rate and production of bacterioplankton increased in those parts of the reservoir where the medium-sized cocci and coccobacilli accounted for from 18.2 to 29.3% of the total abundance. The highest bacterial activity was recorded in the area affected by the warm waste waters of the Volgorechensk State District Power Plant. Based on the data obtained, the reservoir divided on the upper river section and the lower lake section.

The mycobiota on dead submerged plant parts of Phragmites australis reed (leaves, stems, leaf sheaths) was studied in lakes – Pleshcheyevo, Mostetskoye, a lake in the Zavolzhsky district of Yaroslavl and the Kotorosl river (Yaroslavl region, Russia). The kingdom Fungi is represented by 53 species belonging to 33 genera, 25 families, 12 orders, and 7 classes in 2 taxonomic phyla: Mucoromycota (4 species), Ascomycota (48). The kingdom Chromista (fungi-like organisms) includes 8 species belonging to 3 genera, 2 families, 2 orders, and 1 class under phylum Oomycota. For the first time, 23 species of micromycetes were found on reeds. Representatives of the orders Pleosporales (16 species), Helotiales (11), Saprolegniales (7), Hypocreales (5) prevailed. The number of species of fungi on fragments of plants in different aquatic bodies varied from 16 to 39, the statistically significant difference in the species composition of communities of dead reeds was found between a lake in the Zavolzhsky district of Yaroslavl and the Kotorosl River (R = 0.646, significance level of sample statistic 0.1%).

Plankton metabolism determines fluctuations in the oxygen concentrations of a water body, its ecological condition, and exchange of СО₂ with the atmosphere. We used an automated device that allowed us to make mass measurements of intraday values of the gross primary production (GPP) and respiration (R) of plankton. During our studies of the Mozhaisk reservoir (Russia) in the summer of 2017, we established an important fact: the maximum values of GPP are observed essentially earlier in the daytime than those of R. This is explained by the fact that GPP is related to solar radiation (the maximum values are observed at noon), whereas R is related to the temperature of water, which reaches its maximum several hours after in the afternoon. As a result, the maximum value of dissolved oxygen is observed in the second half of the day, when GPP and R become even. The device we have designed may be used for continuous monitoring of metabolism of plankton and of its responses to various hydrometeorological, hydrochemical and anthropogenic impacts.

This review focuses on cyanobacteria and their metabolites with beneficial properties for humans. Cyanobacteria metabolites are uniquely diverse. Many of them exhibit antibacterial, antifungal, anti-carcinogenic, immunosuppressive, antioxidant types of activity, etc. The problems and prospects of using biologically active products of cyanobacteria metabolism are discussed. The issues of obtaining pharmaceuticals and other valuable products (pigments, enzymes, amino acids, vitamins, biodegradable plastic) are considered, and the potential of cyanobacteria as a source of biofuels is evaluated.

Based on the results of hydrobotanical research in 2015–2021, it has been found that the global expansion of the Bonnemaisonia hamifera Hariot filamentous sporophyte stage had reached the Southern Coast of Crimea (SCC) by 2017. At present, the invader is registered in all horizons of the SCC phytal. Massively developing in the epiphyton of native species, it inhibits their growth, and in some areas it becomes one of the dominants. This changes the appearance, structure, and production indicators of algal communities (up to their degradation in some areas), which makes it possible to attribute this invasive species to the “transformers” category. It has been shown that the invasion develops rapidly, its vector coincides with the direction of the Main Black Sea Current. Eutrophication can play a stimulating role. Presumably, the species is already present on the southwestern and western coasts of the Crimean Peninsula and will populate the western and northwestern regions of the Black Sea in the next one or two years; expansion into the Sea of Azov is also likely. B. hamifera invasion may threaten biological diversity of the of the entire Azov-Black Sea basin, which under the conditions of its relative isolation can lead to ecological catastrophe that will affect all countries in the region. Currently, there are no ways that could stop or slow down the process of invasion.

The Posolskaya Bank methane seep (southern Baikal, depths of ~300–500 m) is characterized by weak metha-ne discharge and the deep occurrence of gas hydrates. The species composition and distribution of nematodes from 44 samples of meiozoobenthos on the seeps (gas unloading point and gas hydrate) and background stations were analyzed. 31 species of nematodes from 12 genera, 8 families and 6 orders were identified; 94% of them were found at background stations and/or in other areas of the lake. The ratio of Baikal endemic and Siberian-Palearctic species was 6 : 1. Endemic species of the genera Paratrilobus and Tripyla dominated occurrence frequency and population density. The data obtained on the heterogeneous distribution of nematodes, the relationship between the density of their population and the presence of filaments of sulfur bacteria, copepod detritus, and ferromanganese crusts in the bottom sediments, as well as the habitation of worms with different types of food. These data are discussed.

Data on spatial and age-related changes in the qualitative composition of food spectra (species and taxonomic diversity of invertebrates used as food objects) and quantitative characteristics (dominant types of food) of the common bream Abramis brama (L., 1758) are presented. Changes in nutrition and the ratio of prevailing taxonomic groups in different age groups are shown as the bream grows in the middle and lower reaches of the Severnaya Dvina River. Analysis of the results showed that the composition food’s lump included both representatives of the bottom fauna and planktonic organisms. Amphibiotic insect larvae, mollusks, and aquatic vegetation were the most numerous among the feeding objects. In addition, juvenile fish were present in the food lump of some age groups. Age variability in bream nutrition is reflected in the size-breadth of the food spectrum – in juveniles and older individuals, the components of nutrition are significantly less than in middle-aged fish.

The species composition of parasites in the estuary of the Penzhina River was studied (114 species). The influence of the specific conditions of the estuary on the parasite fauna was shown. High flow rates, mixing of fresh and sea waters, and the abundance of organic matter determine the predominance among parasites of species with morphological adaptations for reliable fixation on fish tolerant to changes in salinity and associated with benthos in the life cycle. Transitions of parasites to atypical hosts have been noted. The component communities of parasites of most fish species are characterized by high indices of diversity and evenness and low indices of dominance. In the marginal populations of pike and whitefish, they are strongly depleted with pronounced dominants and their change in ontogeny. The Arctic and Pacific elements of the ichthyoparasite fauna testify to the influence of the Arctic and Pacific oceans on its formation.

A new species of diatoms, Aulacoseira сhukotkaensis sp. nov., has been described using scanning electron microscopy. The new species has morphological similarity to other Aulacoseira taxa but can be distinguished from A. alpigena by the number of rows of areolae in 10 µm and the length and shape of spines, from A. helvetica by the valve height and the number of areolae rows in 10 µm, and from A. pardata by the shape of spines and the number of rows of areolae in 10 µm.