Characteristics of economic indicators of growing common carp x amur wild carp hybrids of different genesis in the conditions of industrial hybridization

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. Keywords: yearlings, productivity, cost elements, prime cost, profit, profitability.

Fisheries-biological evaluation of young-of-the-year wild carp-domestic carp hybrid of different genesis

Purpose. To provide a comparative analysis of fisheries and biological parameters of young-of-the-year wild carp-domestic carp hybrids obtained from males of different genetic origin by natural spawning method, with subsequent use in industrial hybridization. Methodology. Cultivation was carried out in pond conditions of the Lviv Research Station of the Institute of Fisheries of NAAS. Material for the study were young-of-the-year wild carp-domestic carp hybrids obtained from age-8 and 9 males of Amur wild carp of different genesis. Stocking density of 4-day larvae in nursery ponds was 20 thousand ind./ha. Growth rate was evaluated by using absolute, relative, daily and specific growth rate according to I.I. Schmalhausen. Feeding of fish was carried out with ground grain, starting from the first decade of July. Statistical processing of the material was performed in Microsoft Excel 2016. Criteria for the analysis of parameters were their average value and arithmetic mean error (M ± m). Findings. According to performed studies, young-of-the-year wild carp-domestic carp hybrids obtained from Amur wild carp males of different genesis in terms of dynamics of weight accumulation and linear growth, survival, fish productivity, hybrids obtained from cryo-males were not inferior to young-of-the-year wild carp-domestic carp obtained from local males. However, according to the main body-build indices, they had similar values but were slightly inferior. Originality. For the first time in Ukraine, a comparative analysis of fisheries and biological parameters of young-of-the-year wild carp-domestic carp hybrids obtained from males of different genetic origin in terms of industrial hybridization was performed. Practical value. The results of this work will provide a comprehensive assessment of fish and biological parameters of young-of-the-year wild carp-domestic carp hybrids obtained from Amur wild carp males of different genetic origin and justify their use in breeding work for further reproduction in breeding farms and to obtain industrial hybrids. Key words: Amur wild carp, genesis, body weight, body length, fatness, fish productivity.

Susceptibility of Pimephales promelas and Carassius auratus to a strain of koi herpesvirus isolated from wild Cyprinus carpio in North America

Cyprinid herpesvirus-3 (CyHV-3, syn. koi herpesvirus) is an important pathogen worldwide and a common cause of mass mortality events of wild common carp (Cyprinus carpio) in North America, however, reference strains and genomes obtained from wild carp are not available. Additionally, it is unclear if fishes in North America are susceptible to CyHV-3 infection due to incomplete susceptibility testing. Here we present the first North American type strain and whole-genome sequence of CyHV-3 isolated from wild carp collected from a lake with a history and recent incidence of carp mortality. Additionally, the strain was used in an in-vivo infection model to test the susceptibility of a common native minnow (Pimephales promelas) and goldfish (Carrasius auratus) which is invasive in North America. Detection of CyHV-3 DNA was confirmed in the tissues of a single fathead minnow but the same tissues were negative for CyHV-3 mRNA and samples from exposed fathead minnows were negative on cell culture. There was no detection of CyHV-3 DNA or mRNA in goldfish throughout the experiment. CyHV-3 DNA in carp tissues was reproducibly accompanied by the detection of CyHV-3 mRNA and isolation on cell culture. Additionally, environmental CyHV-3 DNA was detected on all tank filters during the study. These findings suggest that fathead minnows and goldfish are not susceptible to CyHV-3 infection and that detection of CyHV-3 DNA alone in host susceptibility trials should be interpreted with caution.

Comparison of farmed and wild common carp (Cyprinus carpio): Seasonal variations in chemical composition and fatty acid profile

Chemical composition and fatty acid profile of fillets from farmed and wild common carp were assessed in the course of four seasons. Ten wild and ten0 farmed fish were collected in the middle month of each season (except summer due to unavailability of wild fish) during the year. Lipid and protein contents of the samples decreased from summer to spring (protein: 17.6 ± 0.3–15.9 ± 1.6; 18.2 ± 0.1–17.9 ± 1.4%, in the farmed and wild carp samples, lipid (5.1 ± 0.2–1.5 ± 0.5; 3.8 ± 0.6–2.8 ± 0.9%, respectively; P > 0.05), moisture content of both samples increased in this period (76.7 ± 1.4–81.4 ± 0.4, 75.5 ± 0.6–78.5 ± 0.2 in the farmed and wild carp, respectively). Protein content of wild carp fillet was higher (17.7 ± 0.8% protein vs. and 16.2 ± 1.2%) and moisture content was lower than those of the farmed counterparts (77.65 ± 0.6 vs. and 79.3 ± 0.1, P < 0.05). In all seasons, MUFA were higher than SFA and also the PUFA. In the wild carp fillet, PUFA was higher than SFA in winter and spring but in the farmed carp it was higher in all seasons except the spring. Palmitic, oleic, and DHA were the major SFA, MUFA, and PUFA in the wild carp fillet, respectively. In the farmed carp fillet, the major SFA and MUFA were similar to those in the wild one but linoleic acid was the major PUFA in all seasons. ω-3/ω-6 PUFA ratios in the wild carp fillet were higher than in the farmed counterparts.