No 4 (2023)

This paper presents the state of biota of Drenova reservoir in Bosnia and Herzegovina (B&H) as water quality indicator. The Drenova reservoir has a multiple role: protection of the Vijaka river basin from floods, provision of water for the Prnjavor fishpond, as well as sport fishing. Bearing in mind the multifunctionality of this reservoir, but also the scarcity of data on the biota of this water body, in 2017, research on phytoplankton, zooplankton, macrozoobenthos and ichthyofauna was performed. Based on the obtained results (qualitative and quantitative composition, saprobic index according to Pantle Buck, Shannon index), it was established that the water of Drenova reservoir, as far as phytoplankton and zooplankton community is concerned, corres-ponds to the transition from oligosaprobic to β-mesosaprobic waters while macrozoobenthos and ichthyofauna refer to β-mesosaprobic water. A small number of representatives of phytoplankton (both qualitatively and quantitatively) is noticeable, as well as the absence of species common to this type of aquatic ecosystems in the observed period. The state of macrozoobenthos taxa is expected considering the properties of the substrate of this accumulation. Ichthyocenosis is characterized by a small number of species, but also by a small number of individuals within those species.

Using the electron microscopy, 435 diatom algae from 78 genera of 14 different types of tundra water bodies located in the vicinity of the Ust-Lensky State Reserve, north of the Arctic Circle, on the northern exposure of the slope of the Primorsky Ridge (the eastern spur of the Kharaulakh Range of the Verkhoyansk Mountain system) 435 diatom algae from 78 genera were revealed. Among them, 24 taxa of the species rank and 1 of the generic rank are new to the flora of Russia. Most of the identified species, which are new to the flora of Russia, are found in Europe and are characteristic of oligotrophic water bodies and watercourses. Of all the species under study, 66 species belonging to 28 genera have been identified to the genus, with the largest number of them belonging to the genera Planothidium (7) and Gomphonema (10).

Illustrated descriptions of two new species of free-living nematodes Hofmaenneria baikalensis sp. n. and Paratrilobus longisomus sp. n. found in the Lake Baikal (Russia) are given. Hofmaenneria baikalensis sp. n. is close to H. keoladeoensis Khan et al., 2005, H. niddensis (Skwarra, 1921) Schneider, 1940 and H. sitnikovae Gagarin, Naumova, 2010. It differs from these three species in a presence of crystals in the body cavity and presence of three oval cardial glands. Paratrilobus longisomus sp. n. is close in the body size to P. expugnator (Tsalolichin, 1976) and P. rapis Gagarin, 1991 but it has a relatively shorter and slenderer tail and presence of subterminal seta at the tail end.

Using the analysis of the 16S rRNA of mtDNA nucleotide sequences, the taxonomic composition of gobies of the genus Pomatoschistus of the Black Sea was refined. Among the 12 individuals of the genus Pomatoschistus studied in the Black Sea (Odessa Bay and Kazachiya Harbour, Sevastopol), the species P. marmoratus and P. quagga are reliably identified by haplotypes of the 16S gene. When comparing the parameters of the genetic variation of the most abundant species P. marmoratus from the Black Sea with populations of the Mediterranean Sea, it was found that the Black Sea population of P. marmoratus has all the features of a marginal population, which is probably due to the relatively recent naturalization of this species in the Black Sea. The species P. quagga is for the first time indicated for the Black Sea.

In the Sevastopol Bay (Black Sea), in the autumn period of 2021, fungal complexes were studied on plexiglass plates painted with anti-fouling enamel Bioplast-52 (control) and coatings based on it modified with nanoparticles (NP) Zn-FeO, ZnO and Fe-SiO. 16 species of fungi belonging to seven genera, five families, five orders, three classes of the Ascomycota division have been identified. The species composition was dominated by representatives of the genera Aspergillus (7 species) and Alternaria (4 species). The total number of fungal species isolated on substrates varied from 3 (with ZnO NP) to 8 (Bioplast-52) and with Zn-FeO NP), and by exposure time – from 3 (fourteenth day) to 14 species (sixty-first day). There were no representatives of the genera Aspergillus and Alternaria on the coating modified with Fe-CuO NP; only species of the genus Aspergillus were found on the coating with ZnO NP, the smallest number and number of fungal species were found on these coatings. Fe-CuO and ZnO nanoparticles enhanced the antifouling properties of Bioplast-52 enamel.

During the growing season of 2022, the studies were carried out in the water area of the Bratsk Reservoir (the Angara River) and in the near-dam site of the Bratsk high-level hydroelectric power station. The ecological effects of the hydroelectric dam on the zooplankton in the regulated section of the river were studied and the impact of the zooplankton downstream drift on the feeding conditions of the fish in the Bratsk Reservoir was assessed. It is established that the water column stratification is a significant factor in the ecological differentiation of plankton communities in the upper reaches of the hydroelectric power station. Unlike the warmed-up layer of the epilimnion, a specific, poor in species, low-abundant and low-productive plankton develops in the cold-water hypolimnion, which enters the dam intakes. A rigorous analysis does not reveal a transformation of the community composition, a statistically significant decrease in abundance and productivity, increased mortality of invertebrates during their passage through the dam, deterioration of the water ecological quality in the lower reaches of the hydroelectric power station. Both live and dead zooplankton drifting downstream from the reservoir makes up a significant proportion of the diet of fish, which during the feeding period come as close as possible to the hydroelectric power station and form aggregations exceeding those in the water area of the Bratsk Reservoir in density. The data obtained testify to the effective adaptation of lake-river planktocenosis to the specific natural and technogenic mode of operation of a large hydraulic structure. The local impact of the Bratsk hydroelectric power station has no ecologically significant negative effect on the plankton of the Bratsk Reservoir and the Angara River ecosystems and has a positive effect on the fish population in the lower reaches through the enrichment of its forage base.

Turkey has many ecological characteristics due to its geographical location, allowing it to have a rich biodiversity in freshwater ecosystems. This study was carried out on the Kızılırmak river, the longest river (1.355 km) in the country; it originates and empties into the sea within its borders. The Kızılırmak river serves various agricultural, industrial, drinking water-related, and recreational purposes and greatly contributes to the region’s economy. This study aimed to determine the distribution of the river’s macroinvertebrate fauna and evaluate the impact of environmental variables on species distribution. In addition, using species-based biodiversity indices such as the Biological Monitoring Working Party (BMWP), Average Score per Taxon (ASPT), the Shannon–Wiener index, and evenness analysis, spatial and temporal similarities and differences were determined. According to the results, the ten taxonomic groups in the Kızılırmak river belong to the following categories: Gastropoda (81.5%), Gammaridae (9.8%), Oligochaeta (6.2%) Chironomidae (2.1%), Hirudinea (0.3%), and various others (0.1%). The Shannon–Wiener and evenness indexes were 0.29–1.9 and 0.46–0.14, respectively. TR-BMWP scores are in the poor to very poor water quality classes, and the ASPT ranges from moderate to poor water quality. Correlation analysis between species and physicochemical parameters indicated that the benthic macroinvertebrate fauna diversity of the river is affected by natural and anthropogenic factors.

The paper provides a review features of the strike Teleostei methods – suction, ram and bite, in different representatives at the definitive stage of development with characteristic morphology traits their feeding apparatus at qualitative level. In the paper we describe new traits of construction jaw apparatus some Teleostei species, those testifie in favour application them several methods of the strike separately or at a time during feeding.

The main indicators of infestation of European anchovy Engraulis encrasicolus (L.) with larvae of the nematode Hysterothylacium aduncum (Rudolphi, 1802) in winter were studied in two areas of the Black Sea: off the coast of Crimea and the Caucasus. Regional differences in the indicators of invasion intensity and abundance index in two-year-old and three-year-olds were revealed. When analyzing the values of the extensiveness of invasion, no significant differences were found. Three main factors that determine regional differences in anchovy infestation in the studied areas are analyzed.

The tolerant salinity ranges are 0.008–6 and 0.09–9.3 g/L, respectively, for Ch. plumosus L., 1758 and Ch. balatonicus Devai, Wülker et Scholl, 1983. In the tolerant range of salinity, the level of sodium, potassium, calcium, magnesium in the body of Ch. balatonicus was regulated within 33.9–77.1, 7.7–13.7, 11.9–37.6, 54.7–110.6 mmol/kg wet weight, respectively. The concentration of sodium, potassium, calcium, magnesium in the body of Ch. plumosus was maintained within of 62.7–80.8, 10.6–18, 6.7–12, 2.9–6 mmol/kg wet weight in stage III larvae and 49.6–62.3, 9.7–14.8, 42.5–62.2, 47.9–83.4 mmol/kg wet weight in individuals of IV age. In the optimal salinity range of 0.8–5.3 g/L, the sodium concentration in the body of Ch. balato-nicus was maintained at a constant level, decreased in the critically low zone of 0.8–0.09 g/L, and increased in the critically high zone of 5.3–9.3 g/L. In the critically low and high salinity zone, the organism’s ability to survive is reduced. The content of sodium in the body of freshwater aquatic organisms serves as a reliable criterion for assessing the optimal, critically low and high salinity zones.

The concentration of lysozyme in liver, kidney, spleen and serum, as well as the size of immune organs in male pike Esox lucius L. vary in different seasons of year. The enzyme concentrations in organs and serum are weakly interrelated. The organs by the absolute values of mass show a strong relationship with each other, while the correlation between their somatic indices is very weak. The size of the organs affects the concentration of lysozyme in the organs and serum. The liver plays a major role in annual fluctuations of lysozyme concentration in all the organs and serum. Kidney has a leveling effect on the concentration of the enzyme in liver and serum, whereas liver has the opposite effect. The most profound morphophysiological changes in organs and lysozyme as an indicator of nonspecific immunity coincide with the reproduction period of fish.

A comparative study of the morphofunctional parameters of testicular (non-activated) and urinal (activated) spermatozoa of the common toad Bufo bufo (L., 1758) before and after cryopreservation was carried out. Cryopreservation was performed by a slow method. Sucrose (10%) and dimethylformamide (12%) were used as cryoprotectants. It was shown that the pool of testicular spermatozoa contains significantly more cells with abnormal morphology both before and after cryopreservation. The osmoticity of the base medium for the cryoprotective solution (Ringer’s solution for amphibians – 230 mOsm or urinal plasma – 45 mOsm) had little effect on the survival of testicular and urinal spermatozoa during cryopreservation. Comparison of the morphological and functional characteristics of spermatozoa before and after freezing-thawing indicates that the cryoresistances of testicular and urinal spermatozoa differ slightly.