Purpose. To analyze the existing experience in quantitative and qualitative modelling of commercial fish harvesting and to develop the methodological approaches in determining the optimal catch parameters for gillnets.
Methodology. An adjusted annual commercial mortality rate was used to determine the catches composition in gillnets with different mesh sizes.
Findings. The proposed model was developed within the framework of the generally accepted concept of population dynamics and biomass as a result of mortality and weight growth. It showed the dependence of the size-age structure and total weight of the catch on the mesh size of the grids.
Originality of the work was caused by using the mathematical model that can ensure sustainable use of nature based on the optimal parameters of shutter grids on the possibility of their effective removal of certain age groups of white bream for the first time.
Practical Value: calculations performed according to this model for the white bream of the Kyiv Reservoir showed that it is optimal to use grids with a mesh step of 40-50 mm, which allow to obtain the maximum catch per unit of replenishment and ensure high population fertility.
Purpose. To study ichthyocenoses, species composition and the current state of fish populations in water bodies of the Western Polissya of Ukraine by focusing on their changes under the effect of invasive fish species.
Methodology. Ichthyological studies were carried out in natural and artificial water bodies for various purposes in the Western Polissya of Ukraine during 2007-2017. In particular, fish surveys were carried out using beach seins and gill nets with different mesh sizes in the karst lakes Svityaz and Pischane from the Shatskiy National Nature Park, channel lakes Lyubyaz and Nobel from the Pripyat River basin, right-bank tributaries of the Pripyat Rivers including Styr and Goryn Rivers, Khrinnitske reservoir from the Styr River basin, fish ponds of Bochanitsa village and Progress LLC (Goryn River basin). The material for the study were both the populations of native and invasive fish species.
Findings. The results of our own studies and data of other authors highlighted the issue of the spread of invasive fish species in water bodies of the river-lake network of Western Polissya of Ukraine, presented the diagrams of the distribution of these fish in different water bodies of different origins of the above-mentioned region.
Originality. The greatest threat to the abundance of aboriginal fish species in this region was found to be self-reproducing populations of the brown bullhead (Ictalurus nebulosus), Amur sleeper (Percсottus glenіi), stone moroko or topmouth gudgeon (Pseudorasbora parva), three-spined (Gasterosteus aculeatus) and nine-spined (Punguitius punguitius) sticklebacks. In particular, the composition of their gut content during the spawning period included 95% of eggs of fish species, which spawned in spring, as shown in the diagrams presented in this paper.
Practical Value. The proposed measures to be carried out at the national and regional levels will help prevent the ingress of new invasions and mitigate the impact of the existing ones on the ichthyocenoses of the reservoirs of Western Polissya of Ukraine.
Purpose. Rearing of the European eel (Anguilla anguilla) is a promising area of aquaculture, the development of which in Ukraine and the world is constrained by several factors. Spawning, egg incubation, lack of a stable source of supply of fish seeds – these and other problems, as well as the importance of such studies form a basis for finding approaches for their solution and conducting new large-scale studies. This area attracts attention of scientists, there are certain results and achievements; however, they are still not enough to solve the problems of artificial reproduction of the European eel.
Findings. The authors revised, analysed and systematized literature sources focused on the study of the European eel. As a result, it was possible to identify the main achievements and shortcomings in this area, which are promising for further study. In addition, we identified some obstacles faced by scientists and analysed available methods for their solving.
Practical value. This review can be used to stimulate new studies and technological development towards industrial cultivation of eel in Ukraine, which will allow reducing the impact on natural populations of this species and stabilize its number in the natural environment. In addition, the authors of the article intend to draw attention of scientists and manufacturers to the perspectives and problems of growing and studying the European eel.
Purpose. To investigate the effect of feeding carp with hulless oat during pre-spawning period on the reproductive functions of female carp as well as on qualitative characteristics of the obtained eggs.
Methodology. The objects of the study were females of the Nyvky intra-breed type of the Ukrainian scaly carp breed, which were kept during the pre-spawning period in pond conditions of the State Enterprise “Nyvka” of the Institute of Fisheries NAAS of Ukraine. Females were divided into 3 groups. The first group (Experiment I) was fed with 30% hulless oat, the second (Experiment II) with 100% hulless oat. The control group of fish (Control) was fed with a grain mixture. Experiments were conducted in accordance with current methods used in aquaculture. The mass fraction of protein was determined by the Kjeldahl method, the fat content was determined by S.V. Rushkovsky method. Determination of total lipids was performed by the Folch method. Sampling of water for chemical analysis and its processing in the laboratory was carried out according to O.A. Alokin method according to the Standard of the Ministry of Agrarian Policy of Ukraine. Analytical processing of the material was performed using MS Excel. The criteria for the analysis of studied parameters were their mean values (M) and standard deviations (m).
Results. According to studies, the use of 30% hulless oat in the feed of female carp during the pre-spawning has a positive effect on their production of eggs, as evidenced by an increase in relative fertility by 15.6%, fertilization rate by 4.0%, and survival of the obtained 3-day-old larvae by 5.0%.
According to biochemical parameters of eggs, there was an increase in the amount of essential amino acids by 3.04 and 2.01 g/100 g of protein, and fractions of lipids responsible for energy storage, in particular triglycerides, by 11.56 and 5.62%, phospholipids by 3.65 and 2.37%, and fatty acids by 5.33 and 3.11%, respectively, according to the experimental groups. Instead, cholesterol levels decreased by 13.4 and 25.2%.
Temperature, oxygen, and hydrochemical regimes in the hatchery were within aquaculture standards, except for permanganate oxidation and total iron and chlorine ions.
Originality. The prospects of using hulless oat in feeding brood carp were studied in Ukraine for the first time. The analysis of reproductive parameters of female carp as a result of experimental feeding and evaluation of the qualitative characteristics of eggs and offspring obtained by the method of factory reproduction was conducted.
Practical value. The results of a comprehensive assessment of aquaculture and biological parameters will provide recommendations for the use of hulless oat in feeding female carp during pre-spawning period.
Purpose. To analyze data of available specialized literature and summarize the information obtained on the use of probiotics in modern aquaculture. To review basic principles of classification of existing probiotics, methods of their introduction into the aquatic organisms and mechanisms of action of different probiotic groups.
Findings. The analysis of scientific publications on the use of probiotics in aquaculture for efficient farming in order to reduce fish and shrimp mortality and, accordingly, increase the efficiency of farms has been provided. The literature data on the classification of probiotics depending on the composition and purpose are summarized. Modern and general ideas about the microbiota of aquaculture species are described. The actual ways of probiotic administration into the aquatic organisms are given. The main concepts of mechanisms and results of probiotics action on the host (suppression of pathogenic microflora, improving the quality of the aquatic environment, competition for localization and nutrients, providing the animal with immunostimulants, digestive enzymes and other biologically active substances). The prospects of using probiotics as an alternative to antimicrobial drugs and chemical remedies in aquaculture are shown.
Practical value. The review may be useful for scientists investigating alternative treatments of aquaculture objects and the interaction of aquatic organisms with probiotics.
Purpose. To determine main indicators of economic efficiency in the cultivation of age-1 common carp x Amur wild carp hybrids of different genesis in the conditions of industrial hybridization.
Methodology. The material for the study were yearlings of common carp x Amur wild carp hybrids produced from age-8 and 9 Amur wild carp males of different genesis. Cultivation of experimental yearlings was carried out in pond conditions of the Lviv Research Station of the Institute of Fisheries of NAAS. The calculations were performed according to generally accepted methods in economics. Analysis of economic efficiency was based on actual indicators of economic activity of the cultivation of yearlings of common carp x Amur wild carp hybrids taking into account current market prices for fish seeds.
Findings. The study identified factors, which affected profit obtained as a result of the production process of growing offspring of new genesis.
The most economically promising hybrids, which were obtained as a result of crossing common carp females and Amur wild carp males of different genesis were identified. Growing yearlings of common carp x Amur wild carp hybrids produced from crossing Galician and Lubin carp females with cryo-males of Amur wild carp allows the company to obtain higher conditional profit (6655 and 7412 UAH) and ensure an increase in profitability up to 27.74-28.12% by reducing a production unit cost to 46.8-47.0 UAH.
Originality. For the first time, the indicators of economic efficiency of growing yearlings of common carp x Amur wild carp hybrids produced from two genetically different groups of brood Amur wild carp (age-8 and 9) were analyzed.
Main indicators of the formation of the cost mechanism in production, which comprehensively characterize the efficiency of resource use and the technical level of the production process, were identified.
The economic expediency of growing yearlings of common carp x Amur wild carp hybrids of different genesis in the conditions of industrial hybridization was proved.
Practical value. Study results have both theoretical and practical importance and can be used in further studies to develop technology for growing common carp x Amur wild carp hybrids of different genesis in modern conditions.
Purpose. Forming a thematic bibliographic list of publications on the morphological, ecological, physiological and biochemical characteristics of white bream (Blicca bjoerkna L.), as well as the state of its stocks in natural reservoirs.
Methodology. 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.
Findings. A thematic list of publications with a total quantity of 62 sources covering the time interval from 1960 to 2020, and highlighting ecological characteristics of a member of Cyprinidae family, the white bream, as well as considering the state of its populations has been composed. The literary sources were 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 the study of physiological, biochemical, ecological and other characteristics of Cyprinids, in particular white bream (Blicca bjoerkna L.).