Purpose. Using as an example of a small river, which flows through a bar plain of the Dnipro, to study species composition of the littoral ichthyoplankton, dynamics of its structure during the season and its diversity in different parts of the river.
Methodology. The littoral ichthyoplankton was investigated during four seasons of 2011-2014 on the Vita river, a right tributary of the Dnipro affected by the operation of Kaniv HPP. The research covered the main channel, a permanent backwater connected with the channel, as well as temporarily flooded areas of the floodplain and separated from the channel oxbow lakes. Samples were collected with standard sweep nets and Bagenal buoyant nets. Identification of young fish was carried out under binocular microscope MBS-9. Early life stages of larvae were determined according to the system of V. Vasnetsov. Species diversity of ichthyoplankton was assessed by the Shannon index.
Findings. The littoral ichthyoplankton during May-July mostly consisted of limnophilic fish larvae belonging to a family Cyprinidae. In the river channel and the backwater at the beginning of the period the larvae of roach (Rutilus rutilus) prevailed, later they were substituted by larvae of more thermophilic species, among which the rudd (Scardinius erythrophthalmus) was the most abundant. In the oxbow lakes and temporarily flooded areas in spring the coastal ichthyoplankton was mainly structured by larvae of Carassius sp. and the rudd, in summer the larvae assemblages of oxbow lakes were quantitatively dominated by the sunbleak (Leucaspius delineatus). In areas covered with vegetation the larvae of invasive Chinese sleeper (Perccottus glenii) were firstly found. Rheophilic species among young fish were absent, which indicates unfavorable conditions for their spawning at present hydrologic regime of the river.
Originality. For the first time the coastal communities of early young fish in a small tributary of the Dnipro were investigated, seasonal dynamics of their structure was considered, the main spawning grounds of industrial fish were determined.
Practical value. The obtained results point out the important role of small tributaries of the Dnipro in reproduction of many fishes, particularly the industrial ones. They can serve as a basis for identifying the most suitable places for restoration of fish populations, as well as for proper planning of measures aimed at protection, conservation and restoration of ichthyofauna of small rivers and waters associated with them.
Purpose. An increase in the informativeness and shortening of the timing required for biotesting of water from surface water sources in the city of Zhytomyr with the use of Danio rerio Hamilton-Buchanan instead of the traditional test object Poecilia reticulata Peters and observation of their ethology using the «time sampling» method.
Methods. Water samples were collected from reservoirs of the Teteriv river in April 2016. They were used placed in aquaria (10 dm3), where control and experimental groups were formed according to the following scheme: control group – samples with settled (24 hours) tap water; experimental group D-1 - water samples from the Denishivsky reservoir; experimental group D-2 – from water intake Vidsichne. Test specimens were females of P. reticulata and D. rerio, in which the parameters of typical and non-typical motor activity and feeding behavior were determined. Fish were exposed to water for 12 hours. Water toxicity indexes were determined for both experimental and control groups.
Findings. The studies showed the possibility of using the "time sampling" method for rapid assessment of the water toxicity of surface water sources of Zhytomyr with the use of P. reticulata and D. rerio, which consists in the instantaneous fixation of the number of individuals preferring different behavior acts. D. rerio were more susceptible to the combined action of pollutants in experimental waters than the traditional test object guppies regarding the test reactions of increasing the vector movement and reducing the activity of consumed feed (in 12 hours after the start of biotesting on average by 8,43% in the group D1 and by 11,71% in the group D2). The calculation of toxicity indexes based on the above-mentioned ethological acts, which exceeded 50%, detected an average level of pollution of the experimental water.
Originality. For the first time, the rapid assessment of the water toxicity of surface water sources in the city Zhytomyr was carried out by observing the motor activity and feeding behavior of D. rerio.
Practical value. The results of the research are used for the rapid assessment of the toxicity of water of surface water sources in the city Zhytomyr.
Purpose. To perform a comparative analysis of information diversity indices of phytoplankton development in fish-rearing ponds fertilized with biohumus, Riverm and traditional types of organic fertilizers for the determination of the presence or absence of phytoplankton degradation in these water bodies under the effect of the application of these fertilizers.
Methodology. The article describes the results obtained during three years of the studies of phytoplankton in fish-rearing ponds, in which was carp seeds were grown in monoculture and polyculture using intensive and extensive cultivation technologies. The information diversity of algal communities of ponds was determined by calculating the Shannon index based on quantitative characteristics of phytoplankton development.
Findings. The performed studies have shown that the application of the studied fertilizers did not lead to the degeneration of algal communities in fish-rearing ponds, which would be expressed as a depleted information diversity of phytoplankton quantitative characteristics; the degree of the information diversity of phytoplankton abundance and biomass varied in time independently; the seasonal dynamics of the informative diversity of phytoplankton biomass was shaped by the amounts applied studied organic fertilizers such as cattle humus, biohumus and Riverm; the seasonal dynamics of the information diversity degree of phytoplankton abundance depends mainly on natural factors; an increase in the abundance of blue-green algae by the end of the season, like algal blooms during the season, is not a consequence of the effect of the applied fertilizer.
Originality. For the first time Shannon diversity index was used to characterize the development of phytoplankton in fish-rearing ponds after the application of biohumus and Riverm for their fertilization.
Practical value. The obtained results indicate on the promising use of biohumus and Riverm to stimulate the development of the natural food supply for fish, in particular, when growing carp seeds.
Purpose. To provide the biological assessment of the silver Prussian carp (Carassius auratus gibelio (Bloch, 1782)) commercial stock of the Dnieper-Bug estuary in the conditions of the transformed Dnieper river flow.
Methodology. During the analysis of the biological state of the Prussian carp commercial stock, the main attention was given to the dynamics of age and sexual structure, length-weight growth rate, absolute fecundity and condition factor. The basic data were collected during the work of control-observation stations of the Institute of Fisheries in the Dnieper-Bug estuary during the current century. The collection and processing of ichthyological materials were performed in accordance with the generally accepted methodologies.
Findings. The analysis showed that during the current century, the age structure of the Prussian carp of the Dnieper-Bug estuary was the most labile among other commercial cyprinids. It was found that as a result of an increase in the right wing of the age series, there was a gradual increase of the mean weighted age of its commercial stock. At the beginning of studies (2001-2002), the core of the stock was formed by age-3-6 fish (up ); however in subsequent years, a displacement of dominant groups toward the dominance of age-4-7 fish (more than 80% of the total stock) was observed. At the same time, the relative number of age-3 fish (recruits) was at a relatively high level – up to 10.6%.
The linear growth varied more intensively until the age-5, but it reduced with ageing and did not show high variability. The body weight most variable was in age-4 fish (Cv=9.62%). The noted insignificant deviations in the body weight growth rate of the right wing of the age series was due to stable predominance of females in the stock structure, which were characterized by a variability of the mean weight as a result of different development of gonads.
The dynamics of the age-related changes in the condition factor indicated on a gradual decline Fulton condition factor from 3.47±0.22 in age-3 fish to 3.12±0.06 in age-6 fish. The highest variability of these indexes was typical for age-5 fish (Cv=10.9%; lim=2.46-3.89), that was related to the linear-weight growth and fecundity. With an increase in the age, the variableness of condition factor reduced substantially.
Originality. The paper contains modern and significantly updated data on main biological characteristics of the Prussian carp commercial stock in the transformed conditions of the Dnieper-Bug estuary.
Practical value. The obtained results are a scientific background for rational fishery optimization of commercial pressure on the representatives of valuable fish fauna of the Dnieper-Bug estuary. In current conditions, the presented information is actual enough from the point of view of the maintenance and support the biodiversity of valuable commercial species in natural water bodies of Ukraine.
Purpose. To investigate the effect of the bacterial fertilizer "Phosphobacterin" on the formation of the hydrochemical regime, development of the natural food supply and fish productivity in the growing ponds.
Methodology. The work was conducted according to generally accepted hydrochemical,, microbiological, hydrobiological and fish farming methods.
Findings The article presents the results of a study of the productivity of growing ponds with different methods of the application of the bacterial fertilizer "Phosphobacterin".
It was found that the hydrochemical regime of the experimental ponds was formed under the effect of the source of water supply and measures aimed at intensifying the development of the natural food supply and was favorable for the development of feed organisms and the cultivation of fish seeds.
Application of the bacterial fertilizer at the beginning of the growing season along the water pond surface proved to be little effective for increasing the productivity of the pond ecosystem as a whole. A more effective method of increasing biological productivity, including fish productivity of growing ponds, was the application of "Phosphobacterin" during the growing season both on the bed and on the water surface in combination with the organic fertilizer - cattle humus. In the experimental pond under complex fertilization, the average phytoplankton biomass during the growing season was 1.5 times, bacterioplankton 1.1 times, zoobenthos 2.6 times higher, and the obtained total fish productivity was 1.2 times higher than in the control pond (when applying only cattle humus).
Originality. The peculiarities of formation of hydrochemical and hydrobiological (phyto-, bacterio-, zooplankton, zoobenthos) regimes of growing ponds and the fishery indices are studied, both for bacterial fertilizer "Phosphobacterin" independently and together with the traditional organic fertilizer - cattle humus.
Practical value. Based on the obtained results, we developed temporary recommendations for using the bacterial fertilizer "Phosphobacterin" to increase the productivity of growing ponds.
Purpose. To analyze the results of morphometric measurements and dates of aquaculture-biological characteristics of the young-of-the-year and age-1+ rainbow trout reared under industrial technology at instable conditions of the fish farm “Sloboda-Banyliv”.
Methodology. The study has been performed at the industrial fish farm “Sloboda-Banyliv”, Chernivtsi region. The materials for the study were young-of-the-year and age-1+ rainbow trout obtained from the eggs of autumn-spawning form rainbow trout. The young-of-the-year were reared in a 216 m2 tank with stocking density of 255 ind./m2, age-1+ fish were reared in 108 m2 tank with a stocking density of 33 ind./m2 according to generally accepted methods in trout culture. Morphometric measurements of fish were performed according to I.F. Pravdin. Statistical processing of data was carried out in Microsoft Office Excel (2003). The analysis of values was done in the system of absolute values. The analyzed criteria of the measured parameters were their mean values and standard errors (M±m), deviation (σ), variability coefficient (Cv). Fish were fed with the artificial feed with high protein content manufactured by “Biomar” (Denmark).
Findings. The studies on rainbow trout rearing under industrial conditions showed that fish body proportions did not change with age, however, the length of their fins decreased. The slenderness coefficient in age-1+ fish decreased insignificantly that is typical with increasing body depth. Despite instable rearing conditions, both young-of-the-year and age-1+ fish were characterized by moderate growth rate and high feed-conversion efficiency.
Originality. For the first time, in conditions of Ukraine, a study on the formation of rainbow trout brood stocks in a fish farm with instable rearing conditions was performed with the use of the analysis of phenotypical and productive features.
Practical value. The results of the performed work will provide an opportunity to form a rainbow trout brood stock based on characterized phenotypical and productive features that would have high productive and reproductive features in a fish farm with instable rearing conditions.
Purpose. To investigate the genetic structure of the Galician carp population using microsatellite DNA markers.
Methodology. Blood samples taken from the caudal vein of the specimens of the Galician carp farm "Velykyy Lyubin", Lviv region. (N = 15 persons). When landing, they were labeled with electronic chips of the brand Aqua Pump and A-CHIP. The total DNA was isolated using the standard method, using the Gene JET Whole Blood Genomik DNA Purification Mini Kit (USA). The concentration and quality of DNA were determined on an Eppendorf Bio Photometr biophotometer.
To study the genetic structure of the Galician carp population, four microsatellite markers were used: MFW 06, MFW 15, MFW 23, MFW 31.
Findings. Blood samples taken from the tail vein of fish (n = 15 oz.) Were used as research material. In the course of work, optimal conditions for SSR-PCR analysis have been selected. The conducted studies allowed to determine the factors that have the greatest impact on the amplification efficiency, namely: the concentration of the DNA preparation, the concentration of the primer in the reaction mixture and the number of amplification cycles. In the study group, for all 4 microsatellite loci, only 18 alleles with a molecular weight of 130-343 ng were detected. The number of alleles per locus varied from 3 to 6. The most polymorphous was the locus MFW 23 (6 alleles were detected), and the least polymorphic was the locus MFW 31 (3 alleles were detected). The effective number of alleles in the sample of genotypes studied varied from 2.14 (MFW 31) to 5.23 (MFW 23). According to calculations of allelic frequencies, the main indicators of genetic variability are determined. The maximum level of available heterozygosity is fixed for the MFW 23 locus, the lowest for the MFW locus 31.
Originality. For the first time in 65 years the genetic structure of the Galician carp population has been investigated.
Practical value. The results will be used in further studies of the arboreal of Galician carp.
Purpose. To optimize the conditions of sterlet sperm cryopreservation for works on egg fertilization and for producing viable offspring in the conditions of sturgeon farms. To analyze the effect of sperm freezing in different forms on spermatozoa survival and egg fertilization. To compare the results of cryoprotective solutions with compositions on the results of their use of sterlet sperm fertilization and to analyze their effect on the quality of the produced offspring.
Methodology. The task aimed at optimizing the conditions of sterlet sperm cryopreservation for egg fertilization in the conditions of fish farms were carried out according to generally accepted methods in cryobiology and recommendations of Ye.F. Kopeika. The works with the produced sterlet offspring were carried out according to conventional sturgeon culture methods.
Findings. The studies showed that the optimization of the conditions of sterlet sperm cryopreservation allowed preserving the properties of thawed spermatozoa at the level of native sperm. It was found that the functions of the sperm cryopreserved in liquid nitrogen vapors in granules in solutions with methanol or dimethyl sulfoxide (DMSO) were better preserved in granules when using methanol. The functions of the sperm after its freezing in cryopreservation solutions №№ 5 and 6 were evaluated in the conditions of a fish farm. It was found that the fertilizing capacity of the cryopreserved sperm in the solution № 5 (85.6 %) (with lower osmolality) did not virtually differ from the control (87.6 %) when using 25-60 g of eggs. In the cryopreservation solution № 5, this value was 17.6 % lower. The weight and length gain after egg fertilization with the sperm cryopreserved in both solutions in 3-month fish was higher than in the control.
Originality. Introduction of creatine and fructose into the cryopreservation solution allowed increasing its protective properties and preserving spermatozoa activity after thawing at the level of the native sperm. Sperm cryopreservation in granules allowed optimizing the conditions of low temperature freezing of this sturgeon species and producing high quality viable offspring.
Practical value. The obtained results can be used by sturgeon culturists in the conditions of fish farms for works aimed at producing viable sterlet offspring both for commercial purposes and for restocking into natural water bodies as well as by cryobiologists for works with other fish species.
Purpose. To detect the effect of elevated copper ion concentrations (10 aquaculture Maximum Permissible Limits) on morphological and cytometric parameters of erythrocytes of age-2 Prussian carp (Carassius gibelio Bloch, 1782) in experimental and natural conditions.
Methodology. During the work, summarized results of studies performed in 2015-2016 were used. Morphological and cytometric parameters of Prussian carp erythrocytes were determined in the conditions of natural habitats (Zaporizhzhia reservoir) and an experiment. Copper ion concentration both in the experiment and natural conditions was similar and was 0.01 mg/L (10 aquaculture Maximum Permissible Limits). Experimental studies were performed during 21 days. In the control aquarium, fish were kept in the settled tap water; while in the experimental aquaria, intoxication of fish with copper ions was modelled by introducing CuSO4 in water. Blood smears were examined under 40x and 100 x magnifications with the use of microphotography (digital camera Sciencelab T500 5.17 M).
Findings. The performed hematological studies showed that under the conditions of experimental chronic intoxication with copper ions (0.01 mg/L), age-2 Prussian carp had an increase in the share of immature forms of erythrocytes, increase in the number of erythrocytes with pathological signs (cell wall destruction, atypical forms), increase in the nucleus-cytoplasm ration, but the difference in cytometric parameters of erythrocytes between experimental and control fish was not significant. When comparing the morphometric parameters of erythrocytes of fish kept in experimental and natural conditions with similar copper ion concentrations (0.01 mg/L), a significant increase in the nucleus areas of mature erythrocytes was detected and, correspondingly, an increase in the nucleus-cytoplasm ratio of erythrocytes (by almost 30%) in fish in experimental conditions compared to fish, which lived in the Zaporizhzhia reservoir. An increase in these parameters indirectly indicate on the inhibition of erythrocyte functional activity.
Originality. For the first time, an analysis of the effect of copper ions at a concentration of 0.01 mg/L (10 aquaculture Maximum Permissible Limits) on cytometric parameters of Prussian carp erythrocytes in experimental and natural conditions was presented.
Practical value. The obtained results can be used for detecting adaptation reactions in fish organisms under the conditions of the effect of heavy metals as well as for hydroecological monitoring for detecting the levels of heavy metal pollution in aquatic ecosystems dangerous for hydrobionts.