Purpose. To analyze the results of ichthyological surveys of major commercial fish species of the Dnipro river and Desna river within Chernihiv region and determine the biological parameters, which characterize the state of commercial fish stocks.
Methodology. As input material, the data of commercial catches and results of monitoring surveys performed by Ichthyological Service of Chernihiv Fish Protection Inspection in 2015 have been used. Ichthyological material was collected from gill net catches during spring-summer period. In total, 1191 specimens of different fish species were collected for biological analysis. Collection and processing of the material was performed according to generally accepted methods. The total mortality coefficient (Z) was determined by graphical method with the use of natural logarithms of age group numbers in monitoring catches as a tangent of the regression line. The natural mortality was determined for mean age groups according to P.V. Tiurin. The data of official fishery statistics were used for the work.
Findings. In total, 19 fish species have been recorded in official commercial fishery statistics in the Dnipro river and Desna river within Chernihiv region during last five year; major commercial species were bream (22.9…44.5% of annual total catch), silver bream (24.5…24.7%), roach (14.9–15.4 %), and blue bream (3.3-12.1%). As an integral feature of the conditions of fish existence, the mortality values of major commercial fish species have been established. According to the results of age-length structures of bream, roach, silver bream, pikeperch, pike and Prussian carp stocks, the total mortality coefficients varied within 0.36–0.64; natural mortality ― 0.18–0.44; fishing mortality did not exceed 0.20. As a whole, the parameters, which characterize the state of recruitment and exploitation of studied populations, were at a level inherent to middle-cyclic species with increased natural mortality (excluding bream, roach, and silver bream), sufficient recruitment and moderate level of commercial exploitation.
Originality. For the last 10 years, a detailed analysis of the length structure of major species of commercial fish fauna of the Dnipro river and Desna river was performed and integral parameters characterizing the conditions of forming and exploitation and their stocks were determined.
Practical value. The obtained data were used for the development of allowable catches of aquatic living resources in the Dnipro river and Desna river for 2017–2019.
Purpose. To find qualitative and quantitative parameters of juvenile fish communities as a basis for commercial fish stock and biological diversity in the Dniprо-Bug ria system.
Methodology. Primary data were collected during summer-spring period 2006-2015 from catches of small-mesh fishing gears for catching juvenile fish such as beach seine and trawl. In total, catches of 375 stations were analyzed; the total hauled area was more than 50 thousand m2 of littoral shallow waters. To characterize commercial catches, the data of official fishery statistics. Data collection and processing were performed according to generally accepted methods.
Findings. The data on species composition, abundance and distribution of juvenile fish communities in the Dnipro-Bug ria system has been selected and analyzed. Major trends in the dynamics of catches of fish juveniles per unit effort as an integral feature of natural reproduction and basis for the recruitment of commercial fish stocks have been detected. Reproduction conditions of various ecological groups of fishes have been studied. The dynamics of the qualitative composition of commercial catches has been analyzed. Last years, the majority of commercial catches in the Dnipro-Bug ria system consists of Black-sea sprat (62.2%) and Prussian carp (21.4%); the category of “valuable commercial species” composed 7.3% of the total catch. Self-reproductive fish populations ensured formation of 93.5% of the total catch. i.e. natural reproduction remains the major source of the recruitment of commercial fish stocks in the Dnipro-Bug ria system. According to the data of studies of 2006-2015, juveniles of 18 fish species were recorded in the littoral zone, the majority of which (56.3-57.2%) were low value and secondary species – Prussian carp, Black-sea sprat, atherina. Among valuable commercial species, the most abundant were roach (7.3%) and bream (3.4%); at the same time, these species formed 16.4% of the total catch in gill nets in 2010-2017. The inter-annual dynamics of the abundance of juveniles of commercial fish species during last 10 years has been characterized by positive trends that under condition of the maintenance of optimum hydrological regime of the Dnipro-Bug ria system indicates in the possibility of ensuring stable commercial catches in the nearest future.
Originality. The data on the structure of juvenile fish communities of the lower reaches of the Dnipro river as a component of fish fauna of the Dnipro-Bug ria system have been provided. A detailed description of the dynamics of the number of juveniles of major commercial fish species in an inter-annual aspect has been provided.
Practical value. The obtained results have been used for the development of long-term prognoses of fish productivity parameters as a basis for the regulation of qualitative and quantitative parameters of commercial fishing pressure and conservation measures.
Purpose. To analyze literature sources and summarize the obtained information on the vermiculture of such species of the subclass of Oligochaeta worms as: aulophorus (Dero furcata), sludge worm (Tubifex tubifex), potworm (Enchytraeus albidus), grindal worm (Enchytraeus buchhoizi). To present the achievements in modern biotechnology of these species. To examine the features of their cultivation using various methods, as well as the possibilities and prospects of their use as feed objects in aquaculture.
Findings. This work contains brief information on the biology of four most common in Europe species of Oligachaetes subclass and their rational use in fish farming. The article provides recommendations on the specifics of purchasing and collecting the stock cultures from natural conditions, the best methods of their further cultivation, depending on the needs of farms, the basic requirements for the substrate and feeds. The data on the effective feeding of fish with these worms, as well as the technology of storage of the obtained biomass are presented. A review of scientific papers showed that the above-mentioned species can be used as high-protein additives to the main feed and during the pre-spawning period, given their high caloric content. In fact, the latter indicator and poor mineral composition makes it impossible to feed fish with them on a regular basis.
Practical significance. An array of generalized information will be useful for scientists who are exploring the ways to optimize fish feeding. The presented technology of cultivation of Dero furcata, sludge worm, potworm and Grindal worms can be implemented in fish farms of various industrial capacities as well as in aquarium conditions.
Purpose. To study environmental conditions and individual fish culture parameters in the process of rearing brood sterlet herders in cages at natural temperature regime of water bodies of the forest-steppe zone of Ukraine.
Methodology. The material for the study were age-1–7 groups of sterlet reared in floating cages with areas of 24 m2. Fish were fed by specialized feeds with the content of crude protein of 45–64% and raw fat of ― 12–15%. The individual and mean body weight (g), relative weight gain (%) and fish survival rate (%) were studied; fish production per unit area of cages (kg/m2) and feed costs per unit weight gain (kg/kg) were calculated). The determination of the physical and chemical parameters of the environment was carried out using generally accepted methods in fish culture and hydrochemistry.
Findings. The mean monthly water temperature was in the range of 21.7–26.3°C in the summer. The period with a water temperature of 18–25°C was 75-80 days. The mean daily content of dissolved oxygen varied within the range of 2.4–11.6 mgO2/dm3. The mean monthly oxygen concentration in summer was between 3.7 and 6.2 mgO2/dm3. During the period of fish rearing, minor excesses of normative values have been recorded for some hydrochemical parameters. No mass manifestations of fish diseases were detected. It was established that feed costs per unit of body weight gain (kg) increased with fish age, on average, from 1.29 to 1.98 kg. Fish production in cages was 5.33–11.35 kg/m2. On the seventh year of life, the brood sterlet reached a mean weight of 1796.80 ± 73.33 g (Cv = 20.4%). Survival rates for sterlet of different age groups were 78.50–98.96%. The number of sterlet for the organization of caviar and meat production was calculated.
Originality. Peculiarities of rearing different age groups of sterlet with the use of the methods of industrial aquaculture uncommon in Ukraine under conditions of cage aquaculture systems installed in water bodies with natural temperature regime have been investigated.
Practical value. The results of the study are of interest for the development of modern methods of aquaculture of sturgeons in the conditions of farms of industrial type.
Purpose. To obtain and evaluate crossbred young-of-the-year produced by crossing few-scale type of Ukrainian framed carp strain and Nyvka scaled type of Ukrainian scaly carp strain.
Methodology. Commonly accepted selective breeding and aquaculture methods have been used.
Findings. Successful development of fish farming is possible only with the use of complex intensification of production, one of the main part of which is a well-established selective breeding work aimed at qualitative improvement of breeding strains.
The high level of selective breeding work with the common carp creates new reserves for improving the productivity of ponds. Planned organization of the reproduction of the best strains, their types, the ultimate goal of which is to obtain hybrids, makes it possible to rear fish seeds with better performance than pure-bred carp. Improvement of the quality of the young-of-the-year carp produced as a result of cross-breeding caused by heterosis phenomenon. The presence in the breeding fund of Ukraine of high-yielding strains makes it possible to widely apply the method of industrial cross-breeding. However, not every combination can cause heterosis. Therefore, it is important to know which combination of strains or species shows heterosis with a certain economic parameters. The search for the best heterosexual combinations is an important step towards improving the productivity, along with the development of the most effective complex of intensification measures.
Over the past 20 years, Ukrainian carp farming has been enriched by new breeding achievements – Nyvka scaled, Liubyn scaled and framed, as well as the few-scaled intrabreed types, the effectiveness of which has been insufficiently studied for industrial crossing.
The paper presents the fish-farming characteristics of crossbred young-of-the-year Nyvka scaled and Lebedyn few-scaled strains.
Originaty. Evaluation of the fishery value of the new crosses produced by crossing carps of different genesis has been performed.
Practical value. Use of new crosses and purebred carp will contribute to an increase in the productivity of fishery water bodies.
Purpose. To determine the efficiency of using amaranth (Amaranthus) in carp feeding under standard rearing conditions and under the effect of stress-factors common in aquaculture, in order to activate the antioxidant protection system of their organism.
Methodology. Fishery and hydrochemical studies were conducted according to generally accepted methods. The protein content was determined by the Bretford method. The concentration of diene conjugates was studied using a method based on the reaction of the optical density of a heptane isopropanol lipid extract. Determination of the concentration of TBA-active products was carried out spectrophotometrically by a color reaction with thiobarbituric acid. The activity of superoxide dismutase (SOD) was determined as the percent of the inhibition of nitrosin tetrazolium reduction reaction in the presence of phenazine methosulfate. Catalase activity was determined by changing H2O2 concentration.
Findings. The research was conducted in the aquaria room of the Institute of Fisheries NAAS. The effect on the antioxidant protection system activity of the organism of carp yearlings after addition of amaranth to their diet in the amount of 10% has been analyzed. Rearing was carried out under standard conditions and under the effect of stress-factors that are common for fish culture: pollution of the aquatic environment caused by the introduction of intensification measures; complex contamination of water with simultaneous decrease in the dissolved oxygen content.
The research showed that the additional feeding of amaranth to carps under standard conditions of cultivation, there was a certain tendency to an increase in the content of SOD in muscle and hepatopancreas (by 5.9–8.3%) and to an increase in the content of lipid peroxidation products (by 14.3–15.7%). The effect of stress factors showed more marked tendencies. Thus, in polluted water, the activity of SOD in muscle significantly increased (p˂0.01), at the same time, the content of diene conjugates (p˂0.01) increased. In hepatopancreas, a tendency to a 2.9% increase in the activity of catalase and a 44.1% decrease in the content of diene conjugates was observed. Under the complex effect of stress factors, the activity of catalase and TBA-products in muscles tended to decrease, diene conjugates tended to increase, while SOD increased (p˂0,01). In hepatopancreas, there was a tendency to an increase in the content of catalase and SOD, respectively, by 16.5% and 5.9%. At the same time, the content of products of lipid peroxidation — TBA products (p˂0,01) and diene conjugates (p˂0,001) reduced.
Originality. The analysis of anti-oxidant properties of amaranth and the degree of the effect of feeding this additive to carp yearlings on the antioxidant protection system activity of their organism under standard conditions of cultivation and the effect of stress-factors common for aquaculture have been analyzed.
Practical value. Supplementation of carp diet with amaranth in production conditions can be used as a way to reduce the degree of adverse effects of common environmental stress-factors (contamination as a result of intensive measures and decrease in dissolved oxygen content in water to critical values) on the functional state of fish organism by increasing the antioxidant protection system activity.
Purpose. Forming a thematic bibliographic list of publications publications on the application of classical and newest methods of research in fish genetics and fish selection, as well as in biotechnologies in aquaculture.
Methodolody. The complete and selective methods were applied in the process of the systematic search. The bibliographic core have been formed with the publications exclusively in Ukrainian and Russian from the fund of scientific library of the Institute of Fisheries NAAS of Ukraine.
Results. A thematic list of publications with a total quantity of 80 sources covering a time interval from 1965 to 2018, devoted to the use of some methods of genetic and biotechnological research of various fish species, as well as methods of their selection, was composed. The literary sources are arranged in alphabetical order by author or title, and described according to DSTU 8302:2015 “Information and documentation. Bibliographic reference. General principles and rules of composition”, with the amendments (code UKND 01.140.40), as well as in accordance with the requirements of APA style — international standard of references.
Practical value. The list may be useful for scientists, practitioners, students, whose area of interests covers the questions of genetics, breeding, hybridization and biotechnology in fish farming and ichthyopathology.
Purpose. Forming a thematic bibliographic list of English-language publications on certain issues of vital activity of sturgeon (Acipenseridae), both in natural conditions and in aquaculture. Particular attention was given to species that are not common in aquaculture of Ukraine.
Methods. The complete and selective methods were applied in the process of the systematic search. The bibliographic core was made up of literary sources from electronic archives of world-renowned specialized scientific journals. In particular: Journal of Applied Ichthyology, Environmental Biology of Fishes,Conservation Biology, Lake and Reservoir Management, Estuaries,Freshwater Fisheries, Aquaculture, North American Journal of Fisheries Management, Canadian Journal of Fisheries and Aquatic Sciences, Copeia & others.
Results. A thematic list of main publications including thematic scientific collections, materials of international scientific and practical conferences, scientific articles and abstracts of dissertations was composed. It consists of 187 English-language papers. Presented publications cover the time interval for the last thirty years. The literary sources are arranged in alphabetical order by author or title, and described according to DSTU 8302:2015 “Information and documentation. Bibliographic reference. General principles and rules of composition”, with the amendments (code UKND 01.140.40), as well as in accordance with the requirements of APA style ‒ international standard of references.
Practical value. The prepared list may be useful for scientists, practitioners, students, whose sphere of interests is related to issues of questions breeding sturgeon in aquaculture and conservation of populations of rare species of fish.