Vol 11, No 4 (2018)

An assessment of the impact of streams on the state of littoral communities (phyto-, zooplankton, and macrozoobenthos) in Lake Naroch has been carried out. A similar reaction of littoral communities upon water entering from different streams is recorded. The change in zooplankton abundance correlates with that of phytoplankton and relates to the concentration of nutrient elements. The abundance of macrozoobenthos increases in the sites adjacent to the Kupa and Urliki streams, mainly due to oligochaetes, which could be related with the accumulation of organic matter by streams. The structure of community and biotic indexes indicate that the Kupa and Urliki streams have a low ecological status and impact on the state of littoral communities of Lake Naroch. However, the area affected by streams is not large due to the low water inflow.

Stomatocysts of the rare chrysophyte Chrysococcus furcatus have been recorded from the waterbodies of Yaroslavl and Murmansk Regions, Russia. They were studied by means of SEM. Currently there are five known localities of Chrysoccocus furcatus in Russia including our records.

Materials from waterbodies and watercourses in West and East Siberia have been studied, new data on morphology of some representatives of the genus Geissleria have been obtained, and the systematic position of some species and forms of the genus Geissleria reported in the literature as species has been specified. The number of areolae in 10 µm and marginal structures are used as differential features. Findings of some representatives of the genus Geissleria (G. acceptata, G. declivis, G. decussis, G. mongolica, and G. thingvallae) in the studied water bodies in Russia make it possible to broaden our knowledge of their ranges. The following species that are new for science are described: G. davydovae sp. nov., G. moiseevae sp. nov., G. bondarenkae sp. nov., and G. gollerbakhii sp. nov.

We have carried out a comparative analysis of the morphological features of Twaite shad Alosa fallax based on our own data (Curonian Lagoon, Baltic Sea (2008 and 2009)) and comparative materials (collections of Russian and foreign natural history museums, including published data). The results of this study allow us to assign the Baltic Sea population of Twaite shad to the taxonomic status of subspecies Alosa fallax balticus subsp. nov. The Baltic Sea subspecies differs from other subspecies of Atlantic Twaite shad A. fallax by a lower number of gill rakers (mean 36.7) and vertebrae (53.6) and larger pre dorsal distance (46.2% SL or 41.6–42.7% TL). A. fallax balticus is one of the subspecies that have the lowest number of gill rakers on the first gill arch among subspecies of the species Alosa fallax in the northeastern Atlantic and seas of its basins.

The morphology of the vegetative and generative sphere of the relic species Sparganium gramineum Georgi, collected from lakes of the central region of European Russia (Moscow, Tver, and Yaroslavl oblasts) in 2014–2016, is considered. It is shown that, in regards to its life form, S. gramineum is a vegetatively mobile, clearly polycentric, long-rhizomed, and short-lived plant, a polycarpic with a racemose root system. This bur-reed species has been defined as a nonabundant and uncommon, typically freshwater, stenobiotic plant found in the coastal zone of mesotrophic (rarely oligotrophic) waterbodies. In the waterbodies under study, it forms both pure plant communities and groups with aquatic mixed grasses.

The regional diversity of rheophilic macrozoobenthos communities in North India and Nepal has been studied based on material collected from 450 original quantitative samples in 160 small and large watercourses within the altitude gradient of 200–2800 m above sea level. A total of 22 types of communities from 5 classes are identified: rhithral (hard substrates at rapid flow), crenal (mosaic substrates of small watercourses), pelal (soft sediments), phytal (macrophyte beds), and rhipal (mosaic substrates of river bank edge). Many of the community types occur in different altitudinal temperature zones, but their composition and structure vary as the study proceeds further into the mountains. It has been shown that oriental tropical taxa dominate the lowland tropical zone, endemic subtropical taxa dominate the mid-mountain zone, and Palearctic (Central Asian) groups dominate the high-mountain zone. The key features of tropical rheophilic communities are described in comparison with temperate zone communities. The application of the Ramensky–Grime classification of ecological strategies to macrozoobenthos communities is discussed.

The intrapopulation morphometric variability of the widespread species Arctodiaptomus salinus (Daday, 1885) has been studied in different water bodies of the Mediterranean and Black Sea regions. The authors evaluate the effect of temperature, salinity, and population density; estimate the integral characteristics of the variability levels and connectivity of morphometric parameters; and discuss the possibility of using these integral characteristics for diagnostics of the planktonic-crustacean population status.

The distribution and feeding of the ecological morphs of whitefish is studied in Lake Imandra, the largest subarctic water body. Data on the hydrochemical and hydrobiological characteristics of the reaches of the lake, as well as on the morphological features of the whitefish branchial apparatus with low and medium gill raker number, are obtained. A relationship between feeding preferences of whitefishes and size characteristics and trophic levels of the habitats is revealed.

Three-spined sticklebacks of different ages use various simple strategies of exploratory behavior in an unfamiliar plus maze. These strategies involve a specific order of visits to the maze arms and they alternate during maze exploration. One of the strategies (touring) involves sequential visits to the arms during movement in a clockwise or counterclockwise direction. This strategy reduces the probability of returning to recently visited arms, but it does not require memorizing the sequence of arms visited. Another strategy consists of repeated shuttling between any two arms. Random transitions between arms are also observed. These transitions are difficult to explain within the concept of a specific simple strategy. An analysis of maze exploration strategies is proposed for comparative studies of behavioral organization in organisms of different taxonomic levels occupying different ecological niches.

A parasitological examination of the Chinese sleeper Perccottus glenii was carried out in the water bodies of St. Petersburg and its environs. Twenty-seven parasite species/taxa have been recorded. Host-specific heteroxenous parasites of the Chinese sleeper were not found; this corresponds to the origin of the local populations of this fish from the aquarium-released specimens.

Study deals with peculiarities of four genetic loci alleles’ distribution in different populations of common kilka from some parts of its range. Geographical differentiation in muscular lactate dehydrogenase-A (LDH-A*) allele frequencies between populations was found. Allele LDH-A*100 frequency is higher in native range. Allele LDH-A*120 prevails in Volga populations of kilka probably due to presence of landlocked freshwater form in historical perspective.

A comprehensive study of the main morphophysiological parameters of blood and immunocompetent organs of Polypterus senegalus Cuvier, 1829, one of the most ancient living species of fish, is presented. No fundamental differences in morphological or basic physiological and biochemical parameters of blood or the immune system in comparison with other fish species from polypterus are revealed. The investigated species has well-developed mechanisms of nonspecific protection and a high adaptive potential.

River basins are important for both industrial and agricultural activities. Pollution of air, water and soil is increasing owing to an insufficient number of treatment facilities; thus, most industrial and domestic wastewater either is directly discharged into water or is improperly treated. Here Chironomus spp. mentum deformities were used to determine environmental stress sources. A total of 4701 chironomid larvae were collected from 31 stations located in the Büyük Menderes River Basin. The mean mentum deformity incidence was 2.82%, and the frequency of deformities varied from 0 to 14.7%, with the highest frequencies calculated for the Dokuzsele (14.7%) and Banaz (9%) streams. The feature common among both stations is that they receive wastewater from textile, tannery and agricultural facilities. Our results show that mentum deformities are at least five times more pronounced at the most highly polluted sampling stations and indicate that mentum deformities of chironomid larvae are strongly related to ammonium-N and Cl is positively associated with agricultural and household wastewater.

A device for the automated determination of the primary production (PP) and destruction (D) of organic matter in a water body by the oxygen method is presented. It consists of light and dark bottles with optical dissolved oxygen sensors (Onset, YSI) and the pump changing water in bottles through a predetermined period (3 h). Results of 3-day measurements performed in the Mozhaisk Reservoir have shown that the device describes the studied processes fairly well, significantly facilitating field research. The gross PP obtained during the experiment constituted about 4 mg O₂/(L day), which corresponds to the eutrophic status of the reservoir. The device can be used for studying the functional characteristics of aquatic ecosystems under changing environmental factors such as temperature, illumination, and content of biogenic elements.