Rybohospodars'ka nauka Ukrayiny (Fisheries Science of Ukraine)

18-33

Authors: V. Sondak, V. Bihun, O. Volkochovets, N. Kolesnik, M. Simon

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.

45-58

Authors: N. Syrovatka, O. Deren, D. Syrovatka, R. Palamarchuk

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.

82-92

Authors: U. Kuts, H. Kurinenko, Ya. Tuchaps’kyi, I. Buriak, I. Hrytsyniak

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.