scholarly journals DIEL AND INTER-SEASONAL DYNAMICS OF SPATIAL DISTRIBUTION OF FISH IN WATER AREA OF WINTERING RIVERBED DEPRESSION

2021 ◽  
Vol 2021 (3) ◽  
pp. 55-68
Author(s):  
Andrey Aleksandrovich Chemagin
Keyword(s):  
Spatial Distribution ◽  
Dark Period ◽  
Water Area ◽  
Light Period ◽  
Diurnal Dynamics ◽  
Entire Observation Period ◽  
Prey Escape ◽  
Riverbed Depression ◽  
Distribution Of Fish ◽  
Observation Period

To study the dynamics of the spatial distribution of fish under ice cover the research was carried out in the water area of the riverbed depression located in the lower reaches of the Irtysh River (Western Siberia, Tyumen region). The research was conducted by using the hydroacoustic method based on a computerized hydroacoustic software-hardware complex. It was found that, in the diurnal aspect, throughout the entire observation period (December - April), the number of fish in the riverbed increases during the dark period of the day, and during the light period it decreases. The dominant groups of fish change with the change of the period of the day: December - cyprinids prevail in the dark period of the day, in March and April - in the light period of the day, the rest of the time the group of percids predominated. With an increase in water temperature from December to April from 3.7 to 6.5 °C, it was noted that the density of fish decreases from 184 to 8 sp/hect. in the daytime and from 2157 to 91 sp/hect. at night (dark period), respectively. Fish explore the horizons of the water column of the riverbed depression during the day and night from the surface to the bottom with the highest density indicators near the surface, except - the daytime in December. With increasing density of fish at nightfall at the same time, there was an increase used water area of riverbed depression. In the vertical aspect, cyprinids avoid predators (pike, in-connu, burbot) in the diurnal dynamics; the distribution of cyprinids has a significant negative cor-relation with the distribution of the second group of fish. Thus, the features of the vertical and hori-zontal distribution of fish in the diurnal dynamics throughout the entire observation period are the strategy of their survival: for prey - escape from predators, for predators - search for food objects

scholarly journals Distribution of sturgeon in the River Irtysh

2020 ◽  
Vol 11 (3) ◽  
Author(s):  
A. A. Chemagin
Keyword(s):  
Size Structure ◽  
Water Area ◽  
Fish Density ◽  
Low Velocity ◽  
Result Show ◽  
Body Sizes ◽  
Software And Hardware ◽  
And Control ◽  
Riverbed Depression ◽  
Distribution Of Fish

Using the modern hydroacoustic methods and the computerized software and hardware complex “AsCor”, the features of the distribution of fish of the Acipenseridae family in the lower reaches of the large transboundary river the Irtysh (Western Siberia) have been investigated: in the water area of the riverbed depression (turbulent flow) and control sections (laminar flow). The identification of sturgeon was carried out by the echometric method according to the shape of the swim bladder. It is shown that in the water area of the riverbed depression, increased density of fish is formed, the share of sturgeons being 4.9–5.8%. Among other fish species, the group of cyprinids always dominates. The significant excess of the average fish density in the riverbed depression, in contrast to the control, was 6–30 times. In the water area of the riverbed depression, the average fish density was 4,524, in the control sections 245–2,091 individuals/ha. The size structure of the group of sturgeon in the control sections was represented by individuals with body sizes less than 25–30 cm, and in the riverbed depression – by individuals of different sizes and ages with a body length to 35 cm. The water area of the riverbed depression is located in the meandering section of the river and is characterized by intense vertical vortex structures (whirlpools) and the presence of malfunctioning currents. Features of the hydrological characteristics of the riverbed depression are factors in the formation of aggregations of fish, since fish can use the energy of discrete vortices, low-velocity areas, and as a result, show preference for certain turbulence regimes.

scholarly journals DISTRIBUTION OF FISH IN THE PREDATOR-PREY SYSTEM IN THE RIVERBED DEPRESSION OF THE LOWER IRTYSH

2017 ◽  
pp. 76-84
Author(s):  
Andrey Aleksandrovich Chemagin
Keyword(s):  
Vertical Distribution ◽  
Water Column ◽  
Water Area ◽  
Bottom Surface ◽  
Predator Prey ◽  
Prey System ◽  
Irtysh River ◽  
Riverbed Depression ◽  
Distribution Of Fish ◽  
The Irtysh River

The article presents are features of the horizontal and vertical distribution of fish in the water area of the Kondinskaya riverbed depression in the lower reaches of the Irtysh River (Tyumen region, Russia). There have been considered horizons of the water column from the surface to the bottom: surface-pelagic horizon (< 10 m), 1st pelagic horizon (10-20 m), 2nd pelagic horizon (20-30 m), and bottom-pelagic horizon (> 30 m). Hydroacoustic survey was conducted using a software and hardware complex "AsCor" on board a small ship that moved in tacks (zigzags). The recorded information, including the GPS track, processed with special application software "AsCor". Taxonomic belonging to the families was determined remotely - by the type of the reflected sound. According to the data of echometric sensing, main part of fish population on the studied water area was presented by carp species (Cyprinidae) - 66.81%, perch species (Percidae) - 23.77%, cisco species (Coregonidae) - 5.60%, unrecognized species (sturgeon (Acipenseridae)), eelpout species (Lotidae), pike species (Esocidae)) - 3.82% of the registered plurality of fish. All fish groups of the registered mass in terms of abundance have been distributed predominantly in the surface and 1-st pelagic horizons of the water column of the riverbed depression. The difference in the distribution of registered taxonomic fish groups in the vertical aspect from the surface to the bottom is different: in planktivorous fishes more than 190 times, in predatory fishes from 10 to 27 times. A more even distribution of predatory species reduces their aggressive interaction - interspecific and intraspecific competition. There has been revealed a tendency to decrease the percentage of planktivorous species (Cyprinidae) in each succeeding horizon in direction from the surface to the bottom; for Percidae and Coregonidae species and a group of unrecognized fishes it was established, vice versa, in the direction from the bottom to the surface. Due to the wedge-shaped decrease of the living space in the riverbed, the general tendency of a decrease in the number of fish has been registered in the direction of deeper horizons. There has been noted the statistical reliability of differences in the vertical distribution for all registered fish groups. The features of the fish distribution in the predator-prey system on the Irtysh river section with heterogeneous conditions of the aquatic environment (intensive ascending currents and funnels, significant depth changes) characterize it as a "window of antipredation".

scholarly journals Meander reshaping – the formation process of a wintering riverbed depression of fish

2021 ◽  
Vol 29 (4) ◽  
pp. 380-386
Author(s):  
A. A. Chemagin
Keyword(s):  
Life Cycle ◽  
Research Work ◽  
Aquatic Organisms ◽  
Water Area ◽  
Average Density ◽  
Winter Period ◽  
Channel Processes ◽  
Siberian River ◽  
Riverbed Depression ◽  
Distribution Of Fish

The study of the spatiotemporal distribution of fish is an important and poorly studied aspect of the ecology of aquatic organisms. The research work was performed using the modern hydroacoustic method and geographic information systems. A section in the lower reaches of the Irtysh, a large transboundary Siberian river (in Western Siberia, Russian Federation), was studied. It has a strong development of meandering. The merging (i.e., reshaping of closely spaced meanders and erosion-accumulating channel processes) results in development of wintering riverbed depression, which is a critical “temporal bottleneck” during the winter period of the fish life cycle. The average density of fish in the study area in summer and autumn was 8,031 and 9,194 individuals per ha, respectively. Analysis of the distribution of fish showed that the distribution in the horizontal aspect had a more aggregated character in the autumn. In the vertical aspect, it had a more surface (pelagic) character. The ichthyofauna in the water area of the riverbed depression is mainly represented by cyprinids. The loop-shaped evolution of the channel formed a section of the river with multidirectional, circulating, and counter-current flows. It also created zones with depths exceeding 20 m and aggregations of fish. These features characterize the studied water area as a wintering riverbed depression of the fish of the Lower Irtysh. This section of the river should be included in the list of protected wintering biotopes of fish in the West Siberian fishery basin, which will ensure the conservation of fish at the critical stage of the life cycle.

scholarly journals FISH POPULATION OF GORNOSLINKINSKAYA RIVERBED DEPRESSION OF THE LOWER IRTYSH IN WINTER PERIOD

2018 ◽  
pp. 39-47
Author(s):  
Gleb Igorevich Volosnikov ◽  
Andrey Aleksandrovich Chemagin
Keyword(s):  
Water Column ◽  
Fish Population ◽  
Water Area ◽  
Fish Distribution ◽  
Winter Period ◽  
Composition Control ◽  
Ecological Features ◽  
Hydroacoustic Survey ◽  
Riverbed Depression ◽  
Distribution Of Fish

Fish distribution was studied using sonar computerized complex in the deep part of the water column of Gornoslinkinskaya riverbed depression in winter. In the horizontal aspect there was estimated the number of fish registrations, in the vertical aspect the fish density was analyzed in three conditional horizons of the water column: surface, pelagic, bottom. Additionally, the bathymetric characteristics of the riverbed depression in the fish registration areas were evaluated. In the study period the depths were lower than 40 m. On the trajectory of the planned research route there were drilled holes in ice with a motor-drill (screw D=200 mm). Hydroacoustic survey was performed for each drilled hole. To control the species composition control fishing was carried out by gillnets. The hydroacoustic survey files were further processed in the laboratory using AsCor and Taxonomy applications for carrying out dimensional-taxonomic identification of fish. It has been established that fish inhabits the water area of the riverbed depression non-uniformly, both horizontally and vertically. The density of fish in the horizons of the investigated water area is distributed in descending order: pelagic - 105 sp./ha, bottom - 61 sp./ha, surface - 18 sp./ha. The features of the taxonomic distribution of fish are the following: in the surface horizon there are not found percid species and non-identified fish, their shares are decreasing from the bottom to pelagic horizons. The groups of cyprinids and whitefish-pike fish are registered throughout the water column of the riverbed depression: their shares increase from the bottom to the surface. The uneven distribution of different taxonomic fish groups in the investigated water area can be explained by the ecological features of different species in winter, as well as their trophic-defensive behavior.

Immunocytochemical studies on the behavior of RuBisCO and LHCP II during the cell cycle of synchronized Euglena gracilis

1990 ◽  
Vol 48 (3) ◽  
pp. 662-663
Author(s):  
Tetsuaki Osafune ◽  
Shuji Sumida ◽  
Tomoko Ehara ◽  
Eiji Hase ◽  
Jerome A. Schiff
Keyword(s):  
Cell Cycle ◽  
Immunoelectron Microscopy ◽  
Growth Phase ◽  
Euglena Gracilis ◽  
Dark Period ◽  
Light Period ◽  
Carboxylase Activity ◽  
Immunocytochemical Studies ◽  
Lhcp Ii

Changes in the morphology of pyrenoid and the distribution of RuBisCO in the chloroplast of Euglena gracilis were followed by immunoelectron microscopy during the cell cycle in a light (14 h)- dark (10 h) synchronized culture under photoautotrophic conditions. The imrnunoreactive proteins wereconcentrated in the pyrenoid, and less densely distributed in the stroma during the light period (growth phase, Fig. 1-2), but the pyrenoid disappeared during the dark period (division phase), and RuBisCO was dispersed throughout the stroma. Toward the end of the division phase, the pyrenoid began to form in the center of the stroma, and RuBisCO is again concentrated in that pyrenoid region. From a comparison of photosynthetic CO2-fixation with the total carboxylase activity of RuBisCO extracted from Euglena cells in the growth phase, it is suggested that the carboxylase in the pyrenoid functions in CO2-fixation in photosynthesis.

SPATIAL DISTRIBUTION OF FISH DIVERSITY IN GODAVARI RIVER AT AMBAD STRETCH

2019 ◽  
Vol 34 (1-2) ◽  
pp. 81-93
Author(s):  
D. D. BHUTEKAR ◽  
◽  
S. B. AHER ◽  
M. G. BABARE ◽  
◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Fish Diversity ◽  
Godavari River ◽  
Distribution Of Fish

Studies of rootstocks for stone fruit breeds (sweet cherry) in the condition of Hissar valley in Tajikistan

2019 ◽  
Vol 1 (4) ◽  
pp. 28-34
Author(s):  
Rahima I. Ismoilova ◽  
Sodzhida D. Umarova
Keyword(s):  
Sweet Cherry ◽  
Sour Cherry ◽  
High Specificity ◽  
Stone Fruit ◽  
Wild Cherry ◽  
Phenological Observation ◽  
Entire Observation Period ◽  
The Individual ◽  
Leaf System ◽  
Observation Period

This paper is about studying the rootstocks for stone fruit breeds (sweet cherry) in condition of Hissar valley in Tajikistan. Each type of rootstock has its own biological characteristics and imposes specific requirements for growing and development, both during reproduction in the mother plantation and during the growth of trees. For example, the root system in sour cherry is more superficial that of wild sweet cherry. Therefore, the care of trees grafted on sour cherry and wild cherry and of mother plantation bushes of these rootstocks cannot be same. Besides, there are very significant differences among the individual groups of rootstocks. Wild cherry, Mahaleb cherry and Lubskaya cherry are used as rootstocks in the conditions of the Hissar Valley in Tajikistan. High specificity of sweet cherry cultivar varieties depends on the rootstocks. Phenological observation were carried out in our experiments during years 2013-2018 in order to study their winter resistance, yield capacity and fruit quality. The same care for root and grafted plants was carried out during the entire observation period. At the same time a certain ratio between the leaf system of the rootstock and the graft was maintained by trimming the crown. As a result of the evolution and selection, we have identified the wild cherry forms which are distinguished by the highest yields. The most valuable cultivar varieties are Napoleon cherry and Bagration cherry. Compotes made of these varieties have received high evaluation in tasting.

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