Vol 12, No Suppl 1 (2019)

A first generalization of all available data on algal flora of the Lena River estuary has been performed. As a result of the revision of the data obtained in accordance with modern taxonomic reports, a species list of algae has been identified (646 species). It is established that the taxonomic structure of algae characterizes the water bodies as arctic undisturbed. Our analysis shows that the Lena River, being a large transiting waterway, shifts boreal flora to the Arctic region. In the zone where seawater and freshwater mix, signs of an edge effect are revealed. The influence of marine flora on all studied water bodies of the lower Lena River (drift of marine and brackish-water algae species) is established.

A biomorphological analysis of three biomorphs of Persicaria amphibia (L.) Delarbre characterized by features of shoot formation under different environmental conditions has been carried out from positions of a systematic approach and modular organization. The shoot systems of all biomorphs are formed according to the sympodial long-shoot formation model and are composed of the same type of elementary modules. Monocarpic innovation shoots, silleptic shoots, and shoots with an incomplete development cycle are universal modules in various habitats. The variability of plant-shoot systems is determined by modular organization and demonstrates the plasticity of the P. amphibia biomorph.

This paper considers the influence of environmental conditions on the specificity of the process of ossification of the skull of yearlings of common newt Lissotriton vulgaris (Linnaeus, 1758), depending on the degree of urbanization. It is found that the degree of sagittal suture closure in the cranial skeleton of yearlings depends on the level of mineralization of surface waters in which the common newt develops. The accumulating nature of urban ecosystems promotes the intensification of the mineral metabolism of juveniles due to the abundance of calciphilous animals in newt habitats and their dominance in the diet of newt yearlings. This contributing factor accelerates the formation of cranial ossifications in animals from the residential part of urban agglomeration.

This paper reports the isolation and identification of the stalked prosthecate bacterium Asticcacaulis sp. VKM B-2400 culture from the ochreous deposits of a creek with predominating iron-oxidizing bacteria. Molecular genetic analysis has demonstrated that, according to the nucleotide sequence of the 1368 bp 16S rRNA gene fragment, the isolated strain is most closely related (99% identity) to the A. taihuensis species previously described based on a single strain. A description of the Asticcacaulis sp. strain VKM B-2400 is provided. It has been demonstrated that the isolated bacteria, the inhabitants of ochreous deposits, neither convert nor accumulate Fe³⁺ compounds and transform their metabolism at high dissolved iron concentrations (0.5 mM). The indicators of the change in metabolism were biomass peptide composition and the accumulation of storage organic compounds in the bacterial cells. The data obtained in the present article is the first report of the effects of high concentrations of dissolved iron (Fe³⁺) on the metabolism of bacteria not belonging to iron-oxidizing bacteria.

Comparative data from field observations in August 2005 and 2013 on phytoplankton and epiphyton productivity in the Ivankovo and Uglich reservoirs (Upper Volga) are presented. The average chlorophyll content (Chl a) varies from 7.6 ± 1.6 to 39.1 ± 0.7 μg/L in plankton and from 6.6 ± 2.8 to 28.4 ± 4.2 mg/m² of the substrate in epiphyton; the daily primary production values are 0.55–1.64 mg C/L and 0.10–0.68 g C/m² of substrate, respectively. Interannual different-direction changes in the development of the two communities have been identified. In the conditions of more intensive heating in 2013, Chl a content in plankton increased by factors of 1.5–2.5 when compared to 2005, while in epiphyton it decreased by factors of 2–3.5 times. In the Ivankovo Reservoir, abounding in large shallow areas, phytoplankton of the pelagic zone accounted for a lower proportion of algae biomass and primary production (66.6–78.6%) than in the Uglich Reservoir (86.5–97.0%), while, on the contrary, the share of epiphyton in the former reservoir (22.2 and 14.2% in 2005; 8.2 and 4.6% in 2013) was 1.8–5.1 times higher than in the latter.

Data on the taxonomic composition of zooplankton in the Sea of Azov and Taganrog Bay are presented for the period of 2005–2015. The main plankton communities have been identified and the changes in the taxonomic diversity of plankton animals and their community structure caused by sea salinization have been analyzed. The salinization of the sea observed these years affected the early summer zooplankton, and the species composition of its communities is shown to become much poorer; their taxonomic diversity decreased 1.4–1.5 times. The increase in salinity caused the replacement of freshwater and brackish water species by the euryhaline copepod Acartia tonsa that spread all over the sea.

A horizontal echosounder has been used to study the spatial distribution of fish in the Savala River lower reaches. Fish densities in different parts of the studied area with varying degree of meandering are compared. It has been shown that river channel morphology influences fish spatial distribution at a high water level in spring. The difference in the density of fish aggregations in areas with varying degrees of river meandering decrease in autumn, with maximum densities being observed in the deepest sections of the river, when an overall decrease in fish density associated with a decrease in water level and downstream migration after spawning has taken place.

A study of the parasitic fauna of the common ruff from Tsipo-Tsipikanskiye lakes (Baunt and Large Kapylushi) has made it possible to identify 19 species, including 12 in the first Lake Baunt and 15 in the second Lake Large Kapylushi. A study of the parasitic fauna of the common ruff in Lake Baunt has been carried out for the first time. Ten species of parasites (ciliates Apiosoma campanulatum and Trichodina sp., monogeneans Dactylogyrus hemiamphibothrium and Gyrodactylus sp., cestodes Cyathocephalus truncatus and Proteocephalus cernuae, trematodes Diplostomum volvens and Tylodelphys clavata, the nematode Raphidascaris acus, and acantocephalan Pseudoechinorynchus borealis) have been recorded in the common ruff from Tsipo-Tsipikanskiye lakes for the first time.

A brief review of the effects of glyphosate-based herbicides on the morphological and physiological–biochemical parameters of fish is presented. The dependence of the effect on the fish species, age and ecology, herbicide concentration, and experimental conditions, as well as on certain anthropogenic factors, is demonstrated.

Invasive mollusk of genus Corbicula, a new species for the Volga River basin, has been found in the Gorky Reservoir in the zone of exposure to the heated waters of the cooler pond of the Kostromskaya thermal electric power station. According to the morphological features and nucleotide sequences of the mitochondrial cytochrome c-oxidase I (COI) gene fragment, the mollusks have been identified as Corbicula fluminea (Müller, 1774). At present, C. fluminea has naturalized and found a new habitat that can become a source of further distribution for the species.