AbstractThe allelopathic effect of extracts from leaf litter of Betula pendula on the initial stages of ontogenesis (seed germination and growth and development of seedlings) of Rumex aquaticus has been studied in laboratory conditions. A significant decrease in laboratory germination by 1.5–36.3 times, depending on the concentration of the extract, is found. The change in the coefficient of inhibition

The quantitative parameters of mantle attachment scars have been studied in freshwater mussel Margaritifera dahurica Middendorff, 1850 (Margaritiferidae, Bivalvia) for the populations of the Amur River (Zabaykalsky krai). It is shown that the density of mantle attachment scars is approximately the same for all shells studied, regardless of their age: an average of 0.72 attachment scars/cm2. According

AbstractIn this study, the resistance limit of Hydrodroma despiciens, which is a common water mite in inland waters, against heavy metal salts such as iron, zinc, cobalt and manganese has been tested. Water mites were sampled in Karamik Lake in Afyonkarahisar, Turkey, during April–August 2015. Separate small lake ecosystems (microcosms) were modeled in the laboratory for each metal salt. Equal amounts

AbstractAn analysis of 181 species of trematodes according to the results of a complete helminthological autopsy of 1970 specimens of 80 waterbird species from reservoirs located in various regions of Azerbaijan has been carried out. Among 181 species of trematodes, 78 species are of northern origin, 39 species are of southern origin, and 64 species are ubiquists. A total of 135 species of trematodes

AbstractThe brine shrimp Artemia is of considerable economic importance in fish and shellfish larviculture. The quality of the Artemia product, differs, in terms of hatching and biometric characteristics, from strain to strain and from location to location. The same applies for their nutritional value which is not constant but varies among strains and within batches of each strain, causing unreliable

AbstractThis paper presents the first data on the flora of silica-scaled chrysophytes (orders Synurales and Paraphysomonadales) in the delta of the Mekong River (Vietnam). A total of 15 taxa have been identified: nine from the genus Mallomonas, one from Synura, and five from Paraphysomonas. Six taxa are reported for the first time from Vietnam. At most sites, 1–2 species per station are recorded. The

AbstractThe rise in temperature to anomalously high values for the Middle Volga (27–29°С) in the Cheboksary Reservoir in the summer of 2010 significantly increased (2–14 times) the biomass of some plankton components (phytoplankton, bacterioplankton, protozoans, and zooplankton) and the community as a whole. The total plankton biomass reached a record value of 3 g C/m3 for deep parts in the Upper and

AbstractExperimental studies have been performed on Tetraselmis viridis (Rouchijajnen) R.E. Norris, Hori & Chihara (Chlorophyta) and Phaeodactylum tricornutum Bohlin (Bacillariophyta) cultures of Black Sea microalgae using TsV-S1 and PtV-S18 algal virus strains isolated from the Black Sea ecosystem. The study assesses the effects of light intensity and the initial abundance of microalgae cells on the

The species diversity, distribution, and morphological features of centrohelid heliozoans (Centroplasthelida) (Haptista: Centroplasthelida Febvre-Chevalier et Febvre, 1984) from freshwaters of Central and Southern Vietnam have been studied using scanning electron microscopy (SEM). Twelve species, belonging to Acanthocystidae, Choanocystidae, Pterocystidae, Raphidiophryidae, and Raphidocystidae families

AbstractIn August of a low-water year (2018), the first correlated data on plant pigments in water column and bottom sediments (BS’s) in the Tsimlyansk Reservoir (Russia) were obtained. In the water column, chlorophyll (Chl) is represented mainly by the active form and its concentrations (16.7–415 µg/L) are characterized by a discrete distribution over the reservoir water area (Cv = 142%). The pigment

AbstractThe spatial distribution and interannual dynamics of the abundance and biomass of heterotrophic bacterioplankton have been evaluated in two recently formed large freshwater reservoirs (the Taishir and Durgun reservoirs, the Great Lakes Depression, Western Mongolia). The total abundance of bacteria range from 2.5 × 106 to 14.5 × 106 cells/mL; biomass is from 45 to 386 mg C/m3. These parameters

AbstractThe species composition of diatoms and cyanobacteria of the periphyton of experimental synthetic polymer materials, which are anthropogenic waste products and damage marine coastal ecosystems, are presented for the first time. A vertical collector with polymer material samples was exposed in Karantinnaya Bay (the Black Sea) at a depth of 1 to 12 m from August 4 to September 18, 2018. A total

AbstractThe ultrastructure of the mesonephros of the natural population of Atlantic salmon smolts (Salmo salar L., 1758) and brown trout smolts (Salmo trutta L., 1758) inhabiting the Luga River in Leningrad oblast, Russia, was studied. The general plan of the mesonephric kidney structure is presented. Specific features of the structure of leukocytes and nephron of salmonids under smoltification are

AbstractA comparison of the response of freshwater alga Chlorella vulgaris Beijer. on a quantitatively identical change in tonicity of growth medium by different osmotics (NaCl and sucrose) has been studied. Upon an increase in growth-medium osmotic potential (regardless the nature of osmoticum), increased thermogenesis and decreased oxygen absorption by Chlorella is observed first. The difference

AbstractAn illustrated description of two free-living nematode species—Leptolaimoides brevicaudatus sp. n. and Paramonhystera affinis sp. n.—from the water bodies of Vietnam is presented. L. brevicaudatus is similar to L. thermastris (Lorenzen, 1966); L. gangioensis Hoang Lai-Phu et al., 2009; and L. asiaticus Gagarin, Nguyen Vu Thanh, 2005 in regards to body size, but differs from these species by

AbstractA study of phytoplankton in Lake Bolshoe Toko (Yakutia) using scanning electron microscopy has made it possible to obtain the first data on the species composition of Bacillariophyta. A total of 162 species and varieties from 47 genera have been identified, including 96 taxa new for the Aldan River basin, 67 taxa new for Yakutia, and 6 taxa (Сymbopleura cf. lura, Fragilaria perminuta, Gomp

AbstractThe taxonomic composition of section Typha, genus Typha L. (Typhaceae Juss.), is considered. An ecological reconstruction for the Cenozoic geological epochs is proposed. The representatives of section Typha reached acme in the Paleogene (Poltavian flora). Climate cooling, first manifested during the Pliocene, was followed by shrinkage and insularization of the Eurasian living range of the section

AbstractTwo species belonging to the genus Reimeria were found in water bodies of Southeast Asia: R. sinuata and R. uniseriata. Species were studied using light and scanning electron microscopy. First species is characterized by biseriate striae and quantitate characteristic that are close with European populations. Second species is characterized by uniseriate striae and large valve sized that is

AbstractForty-four taxa belonging to 14 genera of testate amoebae were recorded in three biotopes: benthal, benthal with an overgrowth of aquatic vegetation and phytal from the coastal zone of the “Marsh Malak Preslavets” protected area. It is found that in regard to taxonomic richness the testacean fauna in investigated biotopes is quite similar. Concerning the species composition and number of specimens

AbstractThe ultrathin structure of carnivorous flagellate Metromonas grandis Larsen et Patterson has been investigated. The predator captures the whole cell of the prey (bodonids or chrysomonads). Cytostome as a cell pocket has not been found. The cell, besides the flagella and small parts of the folds, is surrounded by a fibrous layer 0.05–0.12 µm in thickness which consists of thick and thin bent

AbstractBased on a biomorphological analysis, the structural organization of the Nelumbo nucifera Gaertn. plant is described. The shoot system is represented by semiroselatte polycarpic vegetative–generator axes; the shoot formation model is a monopodial semiroselatte. The anatomical structure of the N. nucifera stem, petiole, and peduncle corresponds to representatives of monocotyledon plants.

AbstractThe interannual changes in the zooplankton of periodically drying (pulsating) lakes at the beginning of the stabilization period of their level regime under conditions of significant fluctuations in the amount of precipitation, air temperature, and water mineralization are analyzed. It has been shown that the amount of precipitation, the increase of which may indirectly enrich the food supply

AbstractThis paper provides a review of literature published in 2000–2016 on the responses of lysozyme in cyprinids, which was experimentally obtained based on substances of different origin. Ten species, representing objects of aquaculture, are studied. The effects of pathogenic and parasitic infection, vaccination, and immunization, as well as immunostimulants, including endotoxins, secondary metabolites

AbstractThe effect of cholinolytics inhibiting the transmission of signals in the cholinergic system on the rate of feeding reaction of juvenile carp Cyprinus carpio L. has been studied. We have revealed differences in the rate and duration of the impacts of cholinolytics affecting M- and N-cholinergic receptors on one of the parameters of the feeding behavior of fish: the rate of feeding reaction

AbstractThe morphology of rare cryophilic species of dinoflagellates Borghiella dodgei Moestrup, Hansen & Daugbjerg from Eastern Europe (Kiev, Ukraine) has been studied. Until now, only two locations of this species—freshwater reservoirs in Italy and Portugal—were known. The original description of B. dodgei from the new locality, drawings, and photos are given in this work. The morphological variability

AbstractNew data on the chlorophyll a (Chl a) content in the water of the Volga River reservoirs are presented. In years with different temperature regimes (2017 and 2018), the content of Chl a varied from minimal 2.2–13.8 to maximal 7.6–50.5 and 25.8–104 µg/L, respectively. As before, the Chl a concentration in the Volga cascade decreases from the upstream reservoirs to downstream ones; the maximum

AbstractA species of Caspian fauna, leech Archaeobdella esmonti, introduced earlier into most reservoirs of the Volga cascade, was recorded for the first time in the Uglich Reservoir in summer 2017. In 2009, A. esmonti was first detected in the Rybinsk Reservoir, where it was successfully established by 2015, and its occurrence frequency increased to 50%. The quantitative and size-weight characteristics

AbstractInformation on the findings of two amphibiotic species new to Belarusian fauna, Osmylus fulvicephalus (Scopoli, 1763) and Sisyra terminalis Curtis, 1854 of the net-winged insect order Neuroptera, is reported. Data on the location, distribution, and ecological and biological characteristics of each species are provided.

AbstractThe activity of glycosidases (maltase activity and amylolytic activity) in the intestinal mucosa of juvenile common carp Cyprinus carpio (L.) under a sharp increase in water temperature depends on its physiological state (satiety or starvation). The fish are acclimated to a temperature of 22°С during the summer (young-of-the-year) and winter (yearling) seasons. An increase in water temperature

AbstractThe thermoadaptive characteristics of the lake minnow Rhynchocypris percnurus (Pallas, 1814) have been obtained for the first time in experimental conditions. The final preferred temperature in adult fish previously acclimated to a water temperature of 15°С is ~23°С. The sublethal temperature, as determined by a critical thermal maximum at a water heating rate of 8°C/h, in fingerlings and adult

AbstractIn vitro studies of the effect of the herbicide Roundup (25 µg/L) on the activity of glycosidases that hydrolyze starch in the intestinal mucosa and chyme of typical (pike Esox lucius L., zander Sander lucioperca (L.), and wels catfish Silurus glanis L.) and facultative (common perch Perca fluviatilis L. and burbot Lota lota (L.)) ichthyophages have revealed the dependence of the strength and

AbstractThe antioxidant glutathione system (AGS) and lipid peroxidation (LP) level in tissues of the Black Sea cockle Cerastoderma glaucum (Bruguière, 1789) have been investigated and compared with those of other Black Sea bivalve mollusks with high resistance to oxidative stress (OS), namely, mussel Mytilus galloprovincialis (Lamarck, 1819) and anadara Anadara kagoshimensis (Tokunaga, 1906). The activity

AbstractSixty-two species of free-living nematodes have been found in samples from four artificial reservoirs in Vietnam; one genus and eleven species are new for science. The dominant species are Dichromadorageophila (de Man, 1876); Sabatieriafoetida Gagarin, Nguyen Vu Thanh, 2008; Paradontophorafluviatilis Gagarin, Nguyen Vu Thanh, 2008; and Terschellingia longicaudata de Man, 1922. A species list

AbstractIn 2013, a new species, Eurytemora caspica Sukhikh et Alekseev, 2013, was described from the northern part of the Caspian Sea. A thorough morphological analysis of Eurytemora from the Volga River basin by the original descriptors of the species has shown that E. caspica, rather than previously assumed E. affinis, actually inhabits the studied area. The species E. affinis itself was not detected

AbstractUnlike in nonregulated rivers, new ecological filters are formed in artificial reservoirs: structures (gradient zones between biotopes) which affect the behavior and distribution of juvenile fish and therefore change parameters of the downstream migration. One distinct feature of such filters is their selective effect on different species and age groups of migrants when they pass boundaries

AbstractStudies on zooplankton in the littoral zone of Bahir Dar Gulf of Lake Tana (Ethiopia) carried out in March 2018 have revealed its high qualitative characteristics and species richness (Rotifera (61 species) Copepoda (4), Cladocera (13)). High quantitative characteristics were also recorded. The maximum abundance and biomass of zooplankton were recorded in the sites with hydatophytes (the degree

The distribution of organic matter (OM), hydrocarbons, phytopigments and ecological–trophic groups of bacteriobenthos has been investigated in the bottom sediments of the internal estuaries of the small Muchke and Toki rivers. The morphological and hydrological characteristics of estuaries influence the quantitative and qualitative composition of the OM in bottom sediments. The investigation into the

AbstractA study of 2536 fish specimens of 22 species from Lake Tana in Ethiopia has revealed the presence of five species of clinostomid metacercariae represented by two genera: Clinostomum complanatum (from Enteromius humilis, E. tanapelagius, and Garra tana), Euclinostomum sp. and Clinostomum brieni (from Clarias gariepinus), and C. phalacrocoracis and Euclinostomum heterostomum (from Oreochromis

AbstractPseudostaurosiropsisgeocollegarum (Witkowski) Morales is reported for the first time from India. This is very rare and neglected species was found from a Powai Lake in Mumbai, Maharashtra, India. This species was described from Poland. P.geocollegarum differs from other three members of the genus Pseudostaurosiropsis by the shape of the valves, size and number of striae in 10 µm. The present

AbstractCultured hydrocarbon-oxidizing bacteria have been isolated for the first time from bacterioplankton in urban Lake Beloye (Moscow). The taxonomic positions of two bacterial strains (2012B and 2012C) isolated from this lake have been determined. Lipids of the strain 2012B comprise C14:0–C19:0 fatty acids, the most abundant of them being C15:0 (54%), C16:0 (17%), C17:0 (10%), and 10-methyl С18:0

AbstractIn August 2016, the pelagic zooplankton (Cladocera, Copepoda, and Rotifera) and meroplankton (veligers of mollusks of g. Dreissena) were studied in four reservoirs of the Kama River (Kama, Votkinsk, and Nizhnekamsk reservoirs, and the Kama Reach of the Kuibyshev Reservoir). A total of 108 species were found; 14 species were new for the Kama River, including five crustaceans introduced from

AbstractThe regional diversity and characteristics of rheophilic macrozoobenthos communities in the western Tien Shan are described based on 370 original quantitative samples from lotic waters in the western Tien Shan (Kyrgyzstan). We have determined altitudinal differences in the composition and structure of the communities in three zones ranging from 1000 to 3700 m above sea level. Twenty-three types

AbstractThe first data on testate amoeba composition from Trang An and Van Long wetlands (Ninh Binh province, Vietnam) was obtained. Sixty-three species and subspecies belonging to 9 genera and 6 families were identified from 108 samples collected from these wetlands. Arcella conica, Difflugia pulex, and D. sarissa were recorded in Vietnam for the first time. Species diversity of wetland Van Long (52

AbstractThe effect of slow magnetic fluctuations, lighting modes, and the combination of these factors on the maturation, lifespan, brood size, and the period between hatching of juvenile specimens in Daphnia magna Straus, as well as on some morphometric parameters of the females and their offspring, have been studied. The lighting modes influence the period between the delivery of offspring and the

During a parasitological survey of nonnative fish species—rudd Scardinius erythrophthalmus—in the Rybinsk Reservoir, the metacercariae Ornithodiplostomum scardinii were found in its brain. This is the first find of this helminth in the Upper Volga basin. The rudd was infected with the prevalence 31.3%, with an intensity of 1–12 parasites per fish. Data on the current distribution of the trematode O

AbstractThe level of lipid peroxidation in the hemolymph, hepatopancreas, gills, and muscles of the swan mussel Anodonta cygnea (L., 1758) of different ages has been studied. The dependence of malondialdehyde content in hemolymph and studied tissues on the age of the mollusk and structural and functional characteristics of tissues is found. The content of malondialdehyde increases in the hepatopancreas

AbstractDescriptions and illustrations are presented for a new genus and two new species of free-living nematodes found in sediments of four artificial reservoirs for shrimp aquaculture. Paradaptonema gen. n. is morphologically close to Daptonema Cobb, 1920, but it has three glands around cardia that are absent in Daptonema, as well as a peculiar structure of the reproductive apparatus in males. Paradaptonema

AbstractThe species composition and abundance of zoobenthos are studied to reveal the structure of bottom invertebrate communities under the effect of biotopical, hydrological, and climatic factors. One hundred and six quantitative samples were collected from 15 pools of rapid rivers (61.6°–67.1° N) from 2003 to 2017 in eastern Fennoscandia. The basic part of the fauna is formed by 151 species, including

AbstractThe results of a study of phytoplankton in Taganrog Bay in the Sea of Azov and the downstream reaches of the Don River carried out in January–November 2017 are presented. A total of 210 species of eukaryotic algae and cyanoprokaryotes are identified. An analysis of the taxonomic, ecological, and geographical composition of the plankton algal flora and seasonal dynamics of biomass of phytoplankton

AbstractThe trophic structure of benthic macroinvertebrate communities in lakes varying in salinity levels (from oligohaline to hyperhaline) in the southern Ob–Irtysh interfluve has been investigated. Four trophic groups of macroinvertebrates have been identified in 48 lakes: (1) predators, (2) grinders, (3) scrapers, and (4) collectors–detritophages and facultative filter feeders. It is found that

AbstractInformation on the pattern of oxygen diffusion in skeletal muscles of bony fish is discussed. This diffusion is determined by a number of variables. Endothelium of microcirculatory vessels should not be considered the main barrier for oxygen diffusion, as it has large pores and perforations. The main diffusion barrier is cytoplasmic and intracellular membranes of muscle fibers. A substantial

The article describes quantitative and structural characteristics of zooplankton of polytypic sites of a water system including a lake, canal, and a water reservoir. It is shown that in the littoral zone of lakes and water reservoirs, the number of species and communities is higher, and biomass, lower. However, in the littoral zone of shallow lake zooplankton in number, took priority due to Rotifera

AbstractResults of a study of the water temperature and phytoplankton abundance in different regions of Lake Baikal according to 15 expeditions from 1994 to 2013 during late summer are present. The spatial distribution and interannual dynamics of phytoplankton are analyzed. The total abundance of phytoplankton in late summer is shown to be high. Its average long-term value for all of the open area

AbstractOn the basis of 120 original stations, macrozoobenthic communities of rivers from two adjacent areas of the Lower Amur Region (Khabarovsk krai) have been described. Rivers basins are characterized by contrasting landscape conditions: the Anyuy River basin in the piedmonts of the Sikhote-Alin mountain range and the Simmi River basin on the Amur Lowland. About 250 taxa of macroinvertebrates have

AbstractFive bryozoan species of the class Gymnolaemata and a single Plumatella emarginata species of the class Phylactolaemata are found in the Caspian Sea. The class Gymnolaemata is represented by bryozoans of the orders Ctenostomatida (Amathia caspia, Paludicella articulata, and Victorella pavida) and Cheilostomatida (Conopeum grimmi and Lapidosella ostroumovi). Two species (Conopeum grimmi and

AbstractThe accuracy of estimating the relative abundance of generations of fish species under conditions of incomplete initial information is analyzed. Using the example of bream from the Kuibyshev Reservoir, it is shown that, if the information on the age structure is lost for 1 to 8 years, the error in estimating the abundance of generations averages from 5 to 15%. This makes it possible to apply

AbstractData on the dynamics of anadromous migration, age composition, body length, body weight, and morphometric characteristics of Caspian anadromous shad from the Akhtuba River are presented. Currently, Caspian anadromous shad from the Akhtuba River is monomorphic; no temporal groups have been identified. The population is represented by medium-sized young early-maturing (age of 2–3 years) fish

AbstractThe structural parameters of phytoplankton in the estuarine region of a small tributary (Ild River) were studied in 2009–2011 and compared with the adjacent sections of the free-flowing section of the river and the pelagic zone of the Rybinsk Reservoir. Phytoplankton of the mouth estuarine region of the Ild River is characterized by high floristic and specific richness, biomass and coenotic

AbstractThis study analyzes the data of spectrophotometric determination of plant pigments in the bottom sediments of Lake Nero based on bottom survey data of 2017. A low variability (Cv = 27–31%) in concentrations of chlorophyll a and pheopigments over the bottom area and vertically in the sapropel cores is established. The values of pigment concentrations in bottom sediments of the lake belong to

AbstractThis study presents data on actual seed productivity and the ability to spread generative diaporas of various Sparganium species. It is established that, by decreasing the actual seed-productivity index, Sparganium species are arranged in the following order: S. microcarpum (Neum.) Domin. > S. emersum Rehm. > S. glomeratum (Laest.) Neum. > S. gramineum Georgi. > S. erectum L. > S. hyperboreum