Purpose.To determine the current species composition of fish and analyze the structure of ichthyofauna of the Stryi River catchment on the basis of field studies, published works and survey data.
Methodology. Ichthyological studies were carried out in 2017–2019 on the Stryi river, as well as its tributaries Rybnik, Zubrytsya, Skhidnytsia and Opir. Adult fish were caught using hook and line gear and hand nets, the larvae and fry were collected using sweep nets and plankton nets. Species identification and morphological analysis of fish were performed according to standard methods. Incomplete biological analysis of most fish, including all individuals of the Red book species, was carried out in situ, with fish being subsequently released in the river.
Findings.The data obtained indicate that at least 27 fish species belonging to 8 families are present in the Stryi river. The typical riverine (rheophilic) species predominate in fish fauna. The limnophilic species in conditions of mountain river are rare, and the distribution of invasive species is limited for now. Ichthyofauna of the Stryi has features of endemism and relictism. 6 species are listed in the Red Book of Ukraine, 10 are in the Berne Convention. Most fishes carry out long-range migrations within the main channel as well as its tributaries. In order to preserve native riverine ichthyofauna, in particular the rare fish species, it is necessary to carefully approach any economic activity within the river basin which disrupts the natural hydrological regime or leads to water pollution.
Originality.For the first time, a comprehensive study of fish fauna in the Stryi River was conducted, the distribution of rare and endangered as well as invasive fish species, was analyzed.
Practical value.The data obtained are necessary for planning measures for the protection of rare and endangered fish species and for the regulation of recreational fisheries. The results of this study were used as a part of the environmental impact assessment of small hydroelectric power plants construction on the Stryi River. Information on the ichthyofauna composition, the distribution of rare and endangered fishes, particularly those, which undertake spawning migrations, is important for consideration when planning any economic activity that disrups the morphology and hydrological regime of the river bed (gravel extraction, bank stabilization, damming etc.).
Purpose. To investigate the distribution of Macrobrachium nipponense in the Dniester river basin in the south of Ukraine. To assess their density and diurnal fluctuations and determine their sex ratios in different waters.
Methodology. Shrimps were caught using crayfish traps of original design with a length of 50-200 cm and special submersible wooden boxes of 100x100x100 cm. Depths and bottom relief at the study sites were determined using a Garmin EchoMAP CHIRP 72sv. The location was established using a GPS unit Garmin gpsmap 78s and Google Maps 2D. The sample size was 4687 individuals, 88 locations of shrimp aggragations were detected. The diurnal population dynamics was studied at 7 sites. Sex and sex ratio of sampled shrimps where determined using a standard biological analysis.
Findings. The analysis of litertures sources showed the pathways of the spread of M. nipponenseacross the territory of the republics of the USSR and the history of its acclimatization in the Dniester River. The currents shrimp stock density and their sex ratios in different water bodis of the lower Dniester were determined. The diurnal dynamics of changes in shrimp populations was studied at different sites in the Dniester and Kuchurgan lagoons. It was found that the local populations of shrimp from different waters differ significantly in terms of their numbers and sex ratios. The circadian dynamics of shrimp population density in the Dniester and Kuchurgan lagoons had a similar character but differed in absolute numbers.
Originality. The distribution of M. nipponense in the lower reaches of the Dniester was studied for the first time. The abundance of this shrimp in different waters and their sex ratio were established. The circadian dynamics of population changes in the Dniester and Kuchurgan estuaries was studied.
Practical value. The results of the study allowed obtaining an objective biological-geographical characteristic of M. nipponense in the conditions of the Lower Dniester basin. The obtained results can be used to assess the state of the natural population of M. nipponense in the lower Dniester and to determine the prospects of its use as an object of domestic fish farming and aquaculture.
Purpose. To determine major aquaculture-biological parameters of rearing sterlet until viable stages during non-traditional early spring period.
Methodology. Mature sex products of sterlet were obtained during a non-traditional fish breeding period (March) from brood fish grown in floating cages in a water body with a natural temperature regime. The weight of sterlet females was 2.6-3.1 kg (2.8 kg on average). Artificial reproduction of sterlet was carried out using methods generally accepted in sturgeon culture after special temperature adaptation of brood fish in a recirculation water supply system. Sterlet free embryos were held with a stocking density of 5–7 thousand ind./m2 in “ICA”-type tanks with an area of 4 m2. Sterlet was grown in the same tanks to viable stages with a stocking density of 1.5 thousand ind./m2. Larvae were fed with Artemia nauplii, followed by transfer to the consumption of artificial feeds of recommended formulations. Determination of fish breeding parameters and physicochemical parameters of the environment was carried out using conventional methods.
Findings. During the egg incubation period, the rate of development of sterlet embryos at the stages of gastrulation was 87.2% on average. Larval survival during the period before switching to active feeding was in the range of 51.3-67.2%. The yield of sterlet fry at the end of the growing period, which lasted 42 days, was 61.3-73.8% with an average fish weight of of 1.6-1.7 g. It was found that the experimental groups of fish did not differ significantly from by growth and survival parameters from sterlet offspring obtained during traditional spawning periods with other technological schemes of modern sturgeon culture.
Originality. Peculiarities of rearing and the level of viability of sterlet offspring of sterlet obtained under factory conditions during non-traditional fish breeding periods were studied.
Practical value. The study results are of interest for the development of modern aquaculture methods for sturgeons in the conditions of industrial fish farms.
Purpose. Study of the effect of amaranth feed additive on the peculiarities of growth, development, feed efficiency and economic component when rearing age-1+ carp; as well as the reproductive performance of female carp based on an analysis of its nutritional and biologically active properties.
Methodology. Two experiments were conducted in which the effect of feeding of age-1+ and female carp with seeds of Ukrainian high-yielding forage amaranth with biologically active properties "Kharkiv-1" on physiological and productive parameters was analyzed. Carp were fed with granulated compound feed with a protein content of 23%, which was additionally supplemented with ground amaranth seeds by granulation method in the amount of 10% to replace the cereal component, pre-subjected to heat treatment. Piscicultural, breeding, hydrochemical and hydro-biological studies were carried out according to conventional aquaculture methods.
Findings. The main hydrochemical parameters were found to be within piscicultural standards. Development of phyto-, zooplankton and zoobenthos on average for the season both in terms of quantity and biomass practically did not differ in both ponds.
When determining the efficiency of the use of ground amaranth seeds in the feeding of age-1+ carp during the growing season, an improvement in piscicultural parameters was found. In particular, the average weight of fish caught at the end of the growing season in the study group was 10.5%, respectively, the fish productivity was 12.2% higher than in the control, and the feed cost was 10.3% lower. Taking into account the cost of fish seeds and the cost of feed growing, an additional income 9.3% was obtained.
It has been found that the addition of amaranth to the diet of female carp during pre-spawning retention positively affects the production of eggs, their fertilizing capacity, and the viability of larvae obtained. Accordingly, an increase in relative working fertility by 3.4%, the percentage of fertilization of eggs by 3%, and the yield of 3-day larvae by 6.7% in the experimental group were observed.
Originality. During the study, based on the analysis of the nutritional and biologically active properties of amaranth, for the first time its effect on the productive performance of age-1+ carp and the reproductive parameters of female carp was studied, as well as the effectiveness of its use in the diet.
Practical value. Finding feed components with high protein content and suitable for introduction in natural environment of Ukraine is topical and necessary to meet the needs of fish industry. Accordingly, the study of the efficiency of introducing amaranth into the diets of different age groups of carp will have a positive effect on growth, survival and reproductive performance, and will also reduce feed costs.
Purpose. To analyze scientific information sources on the experience and outlook of using protein components of non-traditional origin in compound feeds for aquaculture.
Findings. It has been proven that large-scale production of ASIs (Algae, Single cell proteins/oils and Insects — hereinafter ASI) has been achieved during recent years and their economic competitiveness has been demonstrated, while the quality of the end product is comparable to that of fishmeal in terms of essential amino acids and overall nutritional value. Like single-celled organisms, insects are also promising feed ingredients, as they contain not only valuable nutrients but also additional nutrients that are beneficial to animal health compared to conventional feed sources. Despite the fact that the production of insect protein is in its initial stage, pilot studies have shown significant positive results.
The production of ASI-products has a much smaller environmental impact in terms of both greenhouse gas emissions and water and energy consumption. Microbial protein production has a low anthropogenic load, while restrictions on plant protein production are increasing, including limited land, water and fertilizer supplies, and related environmental issues.
In Europe, the idea of developing industrial production of ASIs is gaining ground.
The new European Regulation EU (2015/2283) related to the use of insects and unicellular proteins in animal feed has significantly expanded the list of possible uses. Thus, it is obvious that insects and algae will soon be a global realistic potential alternative or supplement for aquaculture feeds.
Originality. The development of new alternative sustainable feed resources is one of the key long-term solutions to aquaculture food shortages. Currently, most of the alternative feed resources that are used are of terrestrial origin, including vegetable proteins and oils, the main ingredients for aquaculture. Aquaculture is now competing for the use of livestock, energy, and direct human consumption, raising concerns about the impact of the feed industry on global food security.
Practical value. Restrictions on the availability of high-cost animal ingredients and their high cost lead to the widespread use of terrestrial plant products as a major source of protein and energy, which is a definite alternative to marine ingredients. Ideally, providing the feed industry with feed resources of sufficient quantity and quality that will not directly compete with the human food chain. Thus, feed producers and end-users of fish products have been asked whether animal or vegetable by-products are safe when used as feed for aquaculture and whether they are truly capable of competing with fishmeal and fish oil of natural origin.
Purpose. Nidoviruses are wide spread pathogens of animals and humans. The order Nidovirales covers enveloped viruses with one segment of linear positive-sense single-stranded RNA. The order comprises four families including Coronaviridae, Arteriviridae, Roniviridae and Mesoniviridae. Despite numerous studies, Nidoviruses remain poorly understood today. The complexity of replication mechanisms and significant differences in genome size of individual families are the main problem to understand the life cycle of these viruses. Therefore, we tried to analyze the array of special literature data and summarize the information obtained on nidoviral infections of fish and prawns, structural and functional properties of the Nidovirales members, and the symptoms and consequences of diseases caused by them.
Findings. The presented data contain a brief analytical summary of viruses from the Nidovirales order, which infect fish and prawns. The current classification of water nidoviruses is noted. The morphological and genetic structure of fish nidoviruses as well as the known mechanisms of their replication and other functional properties are shown. Particular attention is paid to the description of symptoms and routes of nidovirus infection development in aquatic organisms. However, effective prevention and treatment of nidoviral infections is unknown. Currently, significant number of nidoviruses is insufficiently studied: partially or completely remain uncharacterized mechanisms of replication, genomic structure, the interactions with environment condition and virus spread, etc.
Practical Value. The review may be useful for scientists studying representatives of Nidovirales order and problems associated with diseases caused by these viruses. The description of disease symptoms will help in preliminary diagnosis of nidoviral infections in fish and prawns and raise awareness concerning its possible negative impact on aquaculture. Further development of knowledge about the morphological and molecular biological properties of nidoviruses, as well as the study of disease symptoms in aquatic organisms is promising direction for both purely biological aspects and for sustainable aquaculture.
Purpose.To determine the main parameters of economic efficiency of the use of inactivated baker's yeast as a biologically active additive in the diet of early juveniles of Russian sturgeon.
Methodology.The calculations were carried out according to generally accepted methods for economic studies. For economic analysis, we used the actual parameters of economic activity in current industrial aquaculture of Ukraine with the use of RAS, as well as prices for 2015-2016 on relevant materials, products and means of production.
Findings. The economic efficiency of introducing 5% and 15% (by weight of the main feed) inactivated baker's yeast into the diet of early juvenile Russian sturgeon grown in the RAS has been established. These concentrations allow achieving more than 70% profitability and reducing the prime cost of onefish to 1.72-1.74 UAH, thereby ensuring high, as compared with other options for feeding, parameters as net (372.96 UAH and 366.86 UAH ) and attributable profit (873.0 UAH and 876.0 UAH).
Originality.For the first time, the parameters of economic efficiency of introducing 4 (5%, 10%, 15%, 40% of the weight of the main feed) concentrations of inactivated baker's yeast into the diet of juvenile Russian sturgeon for 28 days, from 25 to 53 days after hatching were analyzed.
Practical Value. The study results have both theoretical and practical importance and can be used in further studies aimed at optimizing the cultivation of juvenile sturgeons in RAS and adjusting existing feeding schemes on fish farms.
Purpose. To establish the efficiency of the use of such minerals assaponite, analcime and bentonite used as feed additives in the main diet of age-1+ carp on their majorfeatures and the economic component of their cultivation in ponds.
Methodology.The experimental works were carried out in the conditions of ponds of the State Enterprise ExperimentalFarm "Nyvka" of the Institute of Fisheries of NAAS during the growing period of 2018. The object of the study were age-1+carp of Nyvka scaly intrabreed type. The study included three experimental and control groups of fish and was conducted in analogous ponds with an area of 0.5 ha each. The diet of fish of the first experimental group ws supplemented with 3% of saponite, the diet of fish of the second experimental group was supplemented with 3% of analcime, and the diet of fish of the third experimental group was supplemented with 2% of bentonite. The control group of fish was fed with a balanced feed, without additives. Hydrochemical and fish farming studies were carried out according to generally accepted methods.
Findings.The study demonstrated that majorhydrochemical parameters during the growing period were within normal limits, but there was an increase in the level of permanganate oxidation of waterwith an increase in water temperature during the summer. However, the level of chlorides was slightly increased during the entire growingseason in the experimental and control ponds.
In the experimental variants, when supplanting the main diet of age-1+ carp with saponite, analcime and bentonite, the total fish productivity of ponds was higher by 0.7%, 13.4% and 3.5%, respectively, with a decrease in feed costs for cultivation compared to control. At the same time, the best survival rate of fish was 69.1% when fish were fed with the feed supplemented with bentonite, versus 64.2% in the control pond.
When analyzing the economic efficiency of the use of these minerals in the feeding of age-1+ carp, a 2% increase in profitability was observed as a result of the supplementation of fish diet with saponite, 16.4% after addinganalcime and 4.2% after adding bentonite compared to control.
As a result of comparative characteristics of the studied minerals, it should be noted that the most promising for use in the feeding of age-1+carp can be analtsim, given the highest rates of weight gain of fish, fish productivity of ponds and as well as the earned profit.
Originality.The efficiency of the use of such minerals as saponite, analcime and bentonite in the feeding of age-1+ carp as non-traditional feed additives was analyzed for the first time. A comparative assessment of their effects on the main fish features and economic parameters of cultivation was performed.
Practical value. Based on obtained positive results of the introduction of the studied minerals into the diet of carp, it is possible to increase fish growth and fish productivity of ponds. The low cost of these non-traditional additives leads to a positive economic effect in the process of fish cultivation. Accordingly, the use of saponite, analcime and bentonite in the conditions of commercial carp cultivation is justified and relevant.
Purpose. Forming a thematic bibliographic list of publications on the rearing of fish and other aquatic organisms in polyculture.
Methods. 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. There was composed the thematic list of publications with a total quantity of 225 sources covering the time interval from 1958 to 2019, and highlighting the biological, environmental, and technological aspects of the introduction of co-cultivation of various fish species, as well as other aquatic organisms in the practice of fish farming. 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 includes issues of improving the technology of modern fish farming based on intensification of pisciculture, as well as the impact of polyculture on the ecosystem of water bodies.