Natural Reproduction Research Articles

About the fertility of pink salmon Iturup Island

The purpose of the work is to present data for the last 15 years and analyze the fecundity of pink salmon at the present stage of its natural and hatchery reproduction on the island Iturup.The research material was based on the results of biological analysis of pink salmon breeders running to spawn in the basins of Prostor and Kurilsky bays (Iturup Island, Sakhalin region) in July-September 2008–2022. Methods used: standard methods of biological analysis, descriptive statistics methods.Results: it was established that over the past 15 years there has been a trend towards a decrease in the weight of female pink salmon. The value of absolute fecundity during this period varied from 289 to 3568 oocytes, and on average, with one exception, ranged from 1277 to 1640 oocytes. Fecundity was positively but weakly correlated with the length and weight of females within each of the annual samples, and the reliability of this relationship was achieved due to the volume of the samples. The relationship between the fecundity and weight was stronger than that between the fecundity and the length of fish. Average fecundity values were closely correlated with the average weight of females, and, therefore, as in the case of fish weight, in the period from 2008 to 2022 there was a trend toward a decrease in average fecundity values.Practical significance: we studied the fertility of female pink salmon from the only large commercial stock in Russia, formed through natural and hatchery reproduction.

Circular Economy within the Organization: Challenges and Opportunities

Over the last decade, the circular economy has emerged as a promising alternative model aimed at reducing CO2 emissions, waste, and resource depletion through a series of practices focused on resource and energy efficiency (Almeida-Guzmán & Díaz-Guevara, 2020). This model optimizes linear production and consumption systems to establish processes in which material flows are used cyclically along with renewable energy sources, thereby creating new business models. Moreover, circular models limit material flows to sustainable levels, respecting ecosystem cycles and natural reproduction rates, while integrating environmentally responsible economic processes (Korhonen et al., 2018). Consequently, the circular economy has a direct impact on the three dimensions of sustainable development: economic, social, and environmental.

Genetic Characterization of Endangered Sterlet (Acipenser ruthenus, Linnaeus 1758) Gene Bank Broodstock, Natural and Cultured Populations in Hungary

The sterlet (Acipenser ruthenus) is the smallest-bodied endangered species among the six native sturgeon species of the Danube River, and self-sustaining populations still inhabit the Hungarian section of the Danube River and its largest tributary, the Tisza River. Their populations are drastically decreasing; however, they still have natural reproduction in these habitats. For the genetic conservation of the species, an ex situ gene bank is maintained in Hungary. The present study aimed to analyze the genetic resources of a gene bank with a near 40-year history and to compare it with natural populations and farmed stocks. Twelve microsatellites were used for population genetics analyses and individual genotyping of 268 specimens from two natural habitats (Danube and Tisza Rivers) and three captive stocks (a gene bank broodstock and two farms). Microsatellites revealed similar patterns among wild populations and gene bank stocks and did not show genetic differentiation (FST: 0.016–0.017) among them. These results confirmed that the gene bank broodstock properly represents the genetic background of the Danube and Tisza populations and is suitable as a source of breeding materials for the restocking programs. Negative trends were detected in the farmed stocks, reflected in reduced polymorphism at a few loci. The results of the principal component analyses indicate the farm stocks’ separation from the wild and gene bank stocks. The present genetic characterization study reveals a valuable captive stock of the endangered sterlet populations and provides unique information about the genetic similarities and differences among farms and wild stocks in Hungary. Our results provide information that contributes to preserving the genetic structure and variability in sterlet populations and supports the management of gene bank broodstock—avoiding inbreeding and preserving the unique genetic background of the Carpathian basin.

Genotyping-by-Sequencing Study of the Genetic Diversity and Population Structure of the Endangered Plant Tsoongiodendron odorum Chun in China

Tsoongiodendron odorum Chun is a large evergreen tree in the Magnoliaceae family and an ancient relict species represented by small wild populations. It has excellent material quality, high ornamental value, and scientific significance. However, due to the complicated natural reproduction and notable habitat destruction, its wild populations must be urgently conserved. We used genotyping-by-sequencing to examine 17 natural populations of T. odorum in China, the species’ primary habitat, to better understand the genetic diversity of this species and use its germplasm resources. T. odorum had a very low level of genetic diversity; its mean values for Ho, He, Pi, and PIC were 0.175, 0.123, 0.160, and 0.053, respectively. With an average within-population Fst of 0.023 and an inter-population gene flow Nm of 10.918, population genetic variation was primarily found within populations, demonstrating minute genetic divergence between populations. The 17 natural populations of T. odorum were divided into two major categories: the Fujian populations in eastern China and the Jiangxi, Guangdong, Hunan, and Guangxi populations in central and western China. Our research contributes to the understanding of T. odorum’s genetic diversity and organization and offers a theoretical framework for the species’ conservation, breeding, and selection.

Some features of natural spawning and problems of artificial reproduction of the cherry salmon Oncorhynchus masou (Brevoort, 1856)

The article discusses certain aspects of the dispersal and biology of cherry salmon, Oncorhynchus masou (Brevoort, 1856). It is noted that the species is the southernmost within the Pacific Salmon family and is also the only member of the Oncorhynchus genus whose habitat is exclusively in Asia. The decline in the number of cherry salmon across their range has been highlighted, and the main underlying factors have been identified. Some features of cherry salmon spawning run in various parts of their range are examined. A long stay of spawners in fresh water before spawning with preservation of feeding behavior is noted, which makes the species an extremely compelling object of recreational and commercial fishing. Some features of natural reproduction, such as spawning timing and fertility, depending on the habitat and size of the spawners, are indicated. The issue of preserving and restoring the species population is touched upon; the most appropriate method of its implementation is the artificial reproduction of the young with subsequent release into the natural habitat. The paper highlights a number of obstacles to the implementation of such programs, such as the undeveloped technology for growing young masu salmon and the difficulty of optimizing the temperature regime at hatcheries. As one of the limitations to increasing release volumes, it is indicated that masu salmon belongs to a species that have a long freshwater period, with the young spending up to three years in the river. A large number of juvenile masu salmon in the river leads to insufficient food supply and high mortality. In order to overcome this factor, it has been proposed to conduct research aimed at stimulating the smoltification of hatchery salmon fingerlings. This measure will allow significantly increasing the number of smolt and the return rates of spawners, which can be removed without affecting the natural populations.

State of knowledge and distribution of the Andean white ear opossum (Didelphis pernigra, Allen 1900) in Colombia

Abstract The Andean white ear opossum (Didelphis pernigra, Allen 1900) is one of the three species of the genus Didelphis reported in Colombia. Here we present a systematic review of D. pernigra in Colombia, with a geographical and altitudinal distribution hypothesis from the country. We reported geographic records and scientific available information of D. pernigra in 40 studies, 55.26 % of the available literature corresponded to local and regional inventories; 23.68 % of other documents were studies about mammal assemblages, while 21.05 % were specific studies about the species and the genus Didelphis in Colombia. We classified literature according to the following subcategories: natural history, diet, inventories, threats, reproduction, uses and perceptions. Most of the literature corresponded to detection in inventories (55.26 %), followed by natural history information (21.05 %) and threats (7.89 %). Research about diet, uses, perception and reproduction, had the lowest proportion with 5.26 %. Regarding distribution, geographic records ranged between 1060 and 3740 m across the three Andean ranges of Colombia. In general, little is known about the ecology or natural history of the species, efforts should be focused on filling the information gaps about natural history, and surveys should fill the distribution gaps along the Western and Central ranges of Colombia.

Harbour porpoise (Phocoena phocoena) in the Wadden Sea World Heritage Site and requirements for trilateral monitoring

The harbour porpoise (Phocoena phocoena) is considered part of the ‘Outstanding Universal Value’ characterising the Wadden Sea World Heritage Site (WS WHS). The Trilateral Wadden Sea Plan aims to preserve the conservation status of the Trilateral Wadden Sea Cooperation Area, encompassing the WS WHS. The plan has specified two conservation targets for the harbour porpoise: (1) viable stocks and a natural reproduction capacity and (2) conservation of habitat quality for its conservation. To assess the current occurrence of the harbour porpoise in the Wadden Sea area, we collated and analysed data from regional and national research projects using telemetry, aerial surveys, strandings and passive acoustic monitoring, obtained over the years 1990–2020. The results illustrate that porpoises occur in both offshore and intertidal waters, showing seasonal movements and changes in local occurrence over time. Some porpoises displayed limited home ranges throughout the year, suggesting a possible residency for some of the animals using the Wadden Sea area. We also showed that methods, frequency and spatial coverage of monitoring activities vary among the countries Denmark, Germany and the Netherlands. We discuss the suitability of the different methods both regarding the challenges of monitoring in the complex Wadden Sea habitat as well as their ability to target the conservation aims of the WHS. We give several recommendations to assess the status of the species to meet the identified conservation aims.

The effect of pollutants on the ichthyofauna of Lake Ladoga and preventive measures

Lake Ladoga is the largest body of water in Europe with huge reserves of drinking water, and has a particularly important sanitary and hygienic significance for the Northwestern region of Russia. The lake has significant fishery importance – annual catches reached 6000 tons. per year. However, over the past few decades, the fishery status of the reservoir has changed significantly. Stocks and catches of the most valuable fish species have sharply decreased as a result of anthropogenic impact – pollution and eutrophication.Chemical-analytical studies of samples of water, bottom sediments, atmospheric precipitation and fish for metals were carried out in the laboratory of fishery ecology of the St. Petersburg branch of the Federal State Budgetary Institution "VNIRO" ("GosNIORH" named after L.S. Berg) on an atomic absorption spectrophotometer AA - 7000 (Shimadzu) according to approved methods (PNDF., 2010; M02-2406., 2013 and M02-902-125, 2005), and in the research laboratory of food and natural objects "ANALECT" of the Institute of the Ministry of Health of the Russian Federation, using the method of atomic absorption spectrometry according to approved methods. Hydrochemical and hydrological parameters were determined using an automatic multiparameter probe Aqua TROLL 500.The southern water area of the lake, which is the most valuable in terms of fisheries, turned out to be the most vulnerable to toxicological effects. Pollution of spawning grounds, toxicosis of fish, violation of natural reproduction in combination with the hydrological features of the reservoir have led to irreversible transformations in the structure of the ichthyofauna as a whole for the entire lake. Pronounced consequences for the ichthyofauna of the reservoir are associated with the sensitivity of fish to pollutants, their ability to accumulate pathological information over a long-life cycle. The hydrological features of the southern water area of Lake Ladoga, combined with the location of pollution sources and the routes of pollutants, make it difficult to carry out preventive measures in this most important fishery area.

Аналіз стану умов відтворення аборигенних іхтіопопуляцій Стир-Горинського гідроекологічного коридору на території Західного Полісся України

Purpose. To investigate the state of reproduction conditions, current and in dynamics since 1922, for native ichthyopopulations (NI) of the Styr-Horyn Hydroecological Corridor (HEC) on the territory of the Western Polissiya of Ukraine. Methodology. The Styr-Horyn HEC was studied according to the following parameters: hydrological regime and duration of water stay on the floodplain; state of the basin surface; speed of channel flow; amount of water exchange; quality of aquatic environment; natural-temporal changes of the channel, floodplains, tributary network; number of ecotones; qualitative and quantitative characteristics of fish juveniles. The hydrological regime was studied using the analysis of runoff hydrographs located in the Volyn, Rivne, and Zhytomyr regions starting from 1922. To assess water quality, KND No. 211.1.4.010-94, “Methodology of ecological assessment of surface water quality by relevant categories”, SOU – 05.01.37-385: 2006, was used. Ichthyological studies were carried out in the field and laboratory according to standard methods with the use of identification keys primarily using the data of test catches and the classification of V. G. Nikolskyi. Statistical and mathematical analysis was performed using the Delfi programming language, relevant computer programs (Mathcad, Excel, Xara) and formulas, including authors’ ones. Findings. An analysis of the Styr-Horyn HEC was carried out on the basis of restorative ichthyoecology using the basin principle and riskology approaches. The hydroecological and ichthyoecological factors affecting the reproduction of NI were studied. The natural fish reproduction localities (NFRL) in this region have been identified. Originality. For the first time, a comprehensive analysis of the state of the reproduction conditions of the Styr-Horyn HEC on the territory of the Western Polissiya of Ukraine was carried out starting from 1922. In addition, a prognostic assessment of the NFRL of this HEC on the territory of Ukraine has been provided. Practical value. The conducted studies are already successfully used in the work of higher educational institutions of Ukraine in the field of training “Aquatic bioresources and aquaculture”.In addition, they are used by fish protection authorities in several regions of Ukraine, in particular for certification of wintering grounds. In the future, their implementation is planned at the level of the national environmental protection policy and in the preparation of regulatory documents regarding the determination of the damage caused and the extent of the damage. Keywords: Pripyat River, Horyn River, Styr River, hydroecology, ichthyoecology, Western Polissiya, hydroecological corridor, natural fish reproduction localities, spawning grounds, wintering grounds, fish migrations, native ichthyofauna.

Характеристика структурных изменений ихтиофауны в северной части Аграханского залива за последние 5 лет

The northern part of the Agrakhan Gulf, which is a part of the Tersko-Caspian fishery complex of Dagestan, plays an important role in the formation of stocks of commercial fish species, having abundant spawning, nursery and wintering grounds. The efficiency of natural reproduction of fish is determined by the state of the hydrological and hydrochemical regime in the reservoir, which in recent years in this reservoir can be characterised as unfavourable. Studies carried out in North Agrakhan in the period from 2018 to 2022 have shown negative changes in the structure of ichthyofauna, manifested in a decrease in the number of juveniles of passable, semipassable, freshwater fish species and an increase in tuvodny fish of the lake-river complex. The number of juveniles of passable fish species has decreased almost twofold, kutum stocks have reached a critical level, the prevailing semi-passable fish species, which account for up to half of the total volume of recorded juveniles, are also decreasing, although to a lesser extent. Freshwater fish species are in a depressed state, the number of juvenile fish is decreasing from year to year, and has decreased more than twofold over the 5 years under study. The total number of segolets of low-value fishery lake-river fish species for 5 years increased 2 times and was 37% of the total volume of all fish species. In general, in the northern part of the bay the dominance of fish species in the northern part of the bay has become dominant among passable fish species - redfish, semipassable fish species - bream, freshwater fish species - redfish, lake-river fish species - redfish and crucian carp. Such species as kutum, pikeperch and practically all freshwater species are at the stage of extinction, mainly tench, which was recorded in catches only once.

Making immotile sperm motile using high-frequency ultrasound.

Sperm motility is a natural selection with a crucial role in both natural and assisted reproduction. Common methods for increasing sperm motility are by using chemicals that cause embryotoxicity, and the multistep washing requirements of these methods lead to sperm DNA damage. We propose a rapid and noninvasive mechanotherapy approach for increasing the motility of human sperm cells by using ultrasound operating at 800 mW and 40 MHz. Single-cell analysis of sperm cells, facilitated by droplet microfluidics, shows that exposure to ultrasound leads to up to 266% boost to motility parameters of relatively immotile sperm, and as a result, 72% of these immotile sperm are graded as progressive after exposure, with a swimming velocity greater than 5 micrometer per second. These promising results offer a rapid and noninvasive clinical method for improving the motility of sperm cells in the most challenging assisted reproduction cases to replace intracytoplasmic sperm injection (ICSI) with less invasive treatments and to improve assisted reproduction outcomes.

The Reintroduction of Brown Trout (Salmo trutta fario) in the Upper Scheldt River Basin (Flanders, Belgium): Success or Failure?

In 2017, the reintroduction of juvenile brown trout in the southwestern part of Flanders (the Zwalm River basin) (Belgium) was initiated. Monitoring during the subsequent years indicated that the released juveniles survived and matured, indicating that sufficient food and good habitat conditions were available. Despite recent fulfilment of free fish migration within the Zwalm River basin and several spawning habitats being present, no natural reproduction of brown trout could be observed. To obtain more insight into the reproduction and maturing of brown trout eggs under natural conditions, an in situ experiment was conducted during 3 consecutive years at 10 different sites within the river basin. The results of our research indicated that egg survival was generally low (<5%). The main causes are most likely a heavy sediment load hampering sufficient oxygen and clean water flow through the redds. In this basin, the sediment load originates mainly from agricultural fields during heavy rain events and consequential run-off. Creating grassy and/or woody buffer strips along watercourses, in combination with changes in agricultural practices, is needed to be able to build up a viable and self-sustaining population of brown trout and also, in a larger context, of other rheophilic fish species.

The grass carp Ctenopharyngodon idella in the southern Western Siberia

The natural area of grass carp Ctenopharyngodon idella includes the river basins of East Asia from the Amur to Xijiang. The habitat of grass carp is rivers, lakes and ponds. It spawning is in rivers with high flow rates, during pronounced rises in water levels, at temperatures above 18 °С (usually 22–24 °С). It feeds mainly on aquatic vegetation. The grass carp is very common aquaculture object, currently it ranks first in the world in terms of commercial cultivation. In the south of Western Siberia, there is significant interest to grass carp not only as an object of cultivation for commercial fish products, but also as a biological meliorator. However, the possibilities of its cultivation are limited by the climatic features of the region. The problem can be solved by obtaining large grass carp fish seeding material under RAS. There are known cases of single captures of individuals of this species of different ages in the Ob, Irtysh, Tom rivers and in the Novosibirsk reservoir, where they probably end up from nearby fish farms. Currently, data about the natural reproduction of the grass carp in the Ob river basin is missing (except, perhaps, the Belovsky Reservoir).

Abnormal expression of natural mating behaviour of captive adult giant pandas is related to physiological stress.

During ex situ conservation, the adaptability of giant pandas to environmental changes is greatly challenged. The issue of natural reproduction in captive giant pandas remains unresolved both domestically and internationally. It hypothesized that the restricted natural reproductive capacity may be linked to abnormal mating behavior expression due to physiological stress resulting from incompatible pairings in confined environments. To test this hypothesis, we utilized ultra-high performance liquid chromatographytandem quadrupole-time-of-flight mass spectrometry (UPLC-Q-TOF/MS) to analyse urine metabolites in captive adult giant pandas during their breeding period. Simultaneously, enzyme-linked immunosorbent assay was employed to measure the levels of cortisol and epinephrine in urine, providing insight into the psychological state of captive giant pandas during mate selection by examining all metabolites and related biochemical pathways. This comprehensive approach aims to fully elucidate the physiological mechanisms underlying the decline in natural reproductive capacity. The metabolomics findings indicate that the aberrant expression of natural mating behaviour in captive adult male and female giant pandas may be associated with dysfunction in amino acid metabolic pathways. The activation of these metabolic pathways is linked to psychological stress, such as the tryptophan metabolic pathway and GABAergic synapse pathway. The results of physiological indicators indicate a significant correlation between the expression of natural mating behaviour in captive adult pandas and the hormone urine cortisol, which is associated with physiological stress. These findings indicate that the atypical manifestation of natural mating behaviour in captive adult giant pandas may be associated with physiological stress induced by incompatible pairings within confined environments.

ДЕМОГРАФІЧНИЙ РОЗВИТОК ПОСТКОНФЛІКТНИХ СУСПІЛЬСТВ: ДОСВІД КРАЇН КОЛИШНЬОЇ ЮГОСЛАВІЇ

The article shows the demographic losses of the states of the former Yugoslavia in the wars of the 1990s and analyzes the trends of the post-war demographic development of Croatia, Bosnia and Herzegovina, Serbia, Montenegro, North Macedonia, Slovenia, and the partially recognized state of Kosovo. Before the start of the wars, the second demographic transition was largely completed in these countries, and the birth rate approached the average European value. There was no significant reduction in the total birth rate in the countries of the Balkan region during armed conflicts. Only in Kosovo and Bosnia and Herzegovina, there was a noticeable decrease in the number of births due to large migratory losses of reproductive cohorts. The impact of the war was manifested in the accelerated transformation of the age-related birth rate, there was a decrease in the early birth rate against the background of an aging motherhood. It was established that in the post-war societies of the Balkan region, except Serbia, there was no compensatory increase in the birth rate. The birth rate in the countries of the former Yugoslavia changed synchronously with those European states that experienced deep economic crises or geopolitical transformations, in particular, joined the EU. Structural and demographic transformations in post-conflict societies are studied. It was found that during the war, the rate of decline in the share of the child population and the rate of demographic aging were higher than the European average. The long-term dynamics of the age structure of the population of the modern post-conflict countries of the former Yugoslavia do not differ in the main parameters from other European countries. It was established that the main factor in reducing the population of the region is forced external migration. The largest specific weight of emigrants from the number of permanent population is in Kosovo and Bosnia and Herzegovina. In these countries, unresolved ethnopolitical problems destabilize the development of society in general, negatively affect the processes of natural reproduction, and act as a deterrent to the return of migrants. Taking into account the analogies of the post-conflict societies of the Balkan region, as well as taking into account the crisis parameters of the demographic situation before the full-scale war of 2022, the scenarios of the demographic development of Ukraine are built. They are due exclusively to probable migration trends. Optimistic and pessimistic scenarios of the demographic development of Ukraine are determined by several external and internal factors. Recommendations regarding the basic principles of the policy of re-emigration of Ukrainian refugees have been provided.

Optimization of Agricultural Economic Management Model and Risk Control Based on Marginal Analysis Approach

Abstract The basic feature of intertwining natural reproduction and economic reproduction in agricultural economic management determines its high risk. This paper calculates the marginal value of each variable input factor in the agricultural economic management mode through the total income function and analyzes the optimal combination between each variable input factor and agricultural output by combining with the theory of diminishing marginal returns so as to maximize the economic returns in the agricultural economic management mode and achieve the optimization of risk management and control in the agricultural economic management mode. The results of the example show that if the incremental index in the agricultural economic management model of Gansu Province is greater than the level of the previous year, the growth of expenses in the agricultural economy is considered effective. It is also found that the risk of natural disasters is the highest in the agricultural economic management model in Gansu Province, especially the average risk value of wind and hailstorms reaches 1.143, which is much higher than the risk of grain production (0.031), which has the lowest risk level. This paper provides an effective reference for optimizing the effective control of risk in the agricultural economic management model and lays the foundation for improving the economic efficiency of the agricultural economic management model.

Design and Probing of Prism-Based SPR Nano-Biosensor for Human Sperm Detection.

Human sperm functioning is crucial for maintaining natural reproduction, but its sterility is enhanced by variations in environmental conditions. Because of these agitating properties, powerful computer-aided devices are required, but their precision is inadequate, particularly when it comes to samples with low sperm concentrations. Therefore, for the first time, this article introduces the sulfide material-based structure for the detection of human sperm samples using the prism-based surface plasmon resonance sensor (SPR) Nano-biosensor. The proposed structure is designed on the basis of a prism-based Kretschmann configuration and includes silver, silicon, a sulfide layer, black phosphorus, and a sensing medium. This work takes advantage of the excitement of surface plasmons and evanescent waves in the metal dielectric region. For the detection process, seven sperm samples are taken, with their concentration, mobility, and refractive index measured by the refractometer. The proposed structure provides a maximum sensitivity of 409.17°/RIU, QF of 97.45RIU-1 and a DA of 1.37. The results provide a substantial improvement in comparison to the reported work in the literature.

К ЮБИЛЕЙНОМУ ДЕСЯТОМУ МЕЖДУНАРОДНОМУ СИМПОЗИУМУ ПО ОСЕТРОВЫМ (ISS10) (Г. ИЧАН, КИТАЙ, 20-25 ОКТЯБРЯ 2025 ГОДА): АКТУАЛЬНЫЕ ВОПРОСЫ

Background. The decline in the population and the threat of extinction that is currently applicable to most sturgeon species, as well as changes in their habitat and spawning environment have been the focus of attention for scientists and governments of different states for many years. Relevance. The preservation and restoration of fishing stocks of valuable sturgeon species and conservation of other vulnerable species are urgent tasks within the scope of rational use of natural resources and conservation of biological diversity and require international efforts. The aim of this work is to consider the main subject matters and focal areas of the upcoming Tenth International Symposium on Sturgeon, which will be held on October 2025 in Yichang (China). Methods. The main topics of the preliminary reports of the participants and speakers of the symposium have been analyzed, as well as the problems set out to be discussed over its duration. Results. This article is intended to familiarize the scientific community of Russia and other countries with the international-level matters associated with the upcoming symposium. Conclusion. The relevance of the international discussion of the current status of studies concerning sturgeon fish species, of increasing their natural reproduction efficiency, their breeding and rearing in the context of declining population abundance have been emphasized, as well as importance of identification of the prospects and challenges in restoration of some species populations with consideration to the dedicated long-term release of sturgeon juveniles into the natural water bodies and exploration of the approaches to their ex situ conservation.

ОСОБЛИВОСТІ ФОРМУВАННЯ ВИТРАТ НА ВИРОБНИЦТВО СІЛЬСЬКОГОСПОДАРСЬКОЇ ПРОДУКЦІЇ В УМОВАХ ВІЙНИ В УКРАЇНІ

The article examines the main specific features of the formation of costs for the production of agricultural products in the conditions of war in Ukraine. The specifics of the "costs" category in the theoretical and practical economic context are outlined. The assessment of costs and losses in the activities of Ukrainian agricultural enterprises during the war requires special attention, as one of the key factors in determining the state and possibilities of the functioning of the national economy. The methodological basis of the correct calculation of the cost of production and sale of agricultural products in the conditions of hostilities becomes one of the key conditions for preserving production and preventing its bankruptcy. The changes in the production of agricultural products that occurred as a result of military actions on the territory of Ukraine, in general in this sector of the economy and in the fields of plant and animal husbandry, have been determined. By the beginning of 2023, production in the industry as a whole decreased by 28%, including in crop production by 39.5%, and in livestock production by 8.2%. It was the closure of enterprises in the war zone and the loss of production capacity that became the main cause of destabilization of the agrarian sector of the country's economy. The scope and specifics of production losses in the industry as a result of hostilities, shelling and mining were assessed. The structure and main elements of material costs for the production of agricultural products in the conditions of war are analyzed. The undoubted advantage of agriculture in the conditions of hostilities is its ability to be self-sufficient and self-reproducing, but with modern technologies, without additional involvement of external resources, at least in the form of fuel and spare parts for machinery and electricity, it is impossible to ensure the production process. In addition, a significant problem is the shortage of labor resources in rural areas. The main elements of production costs in war conditions are disclosed. The importance of natural reproduction in the industry as a factor contributing to lower rates of cost growth in difficult conditions of supply of material resources necessary for intensive production of products was determined and evaluated.

Effects of two diets on growth and condition factor of Chitala lopis

The giant featherback Chitala lopis is fully protected fish species according to Indonesia's official list. The conservation of aquatic resources is achieved through implementing fish farming practices and optimizing feed utilization. This study aims to investigate the impact of different feeding rate on the growth patterns, performance, and condition factors of the first generation of giant featherback. The first generation of the fish were collected from the natural reproduction of broodstock in the earthen ponds. Fish were randomly divided at three different groups replicated three times and reared in the nine net cages installed in the earthen pond. The stocking density of the fish in each group was three fish per cage. The feed treatment involved fish bycatch as control (T0) (5% of the total weight) and freshwater shrimp, Caridina sp. with two different feeding rates including 5% (T1) and 7% (T2) of the total weight, respectively. The mean initial weight of the fish was 41 ± 3.85 g. The survival and absolute growth rate of T1 were highest (29.9±6.38 g, 78± 11%), but it is not significantly different (p0.05). The average relative growth rate of T1 is also highest (76.28±18.61%) and significantly different (p0.05). The growth pattern of the fish at the beginning of the study was negative allometric (0.54), which was low correlated (0.03), and at the end became positive allometric (4.17), which was moderately correlated (0.66). The highest condition factor was T2 (0.78±0.03) and had a significant effect (p0.05). Caridina sp. has a good impact on the first generation of giant featherback weight growth compared to other treatments in this study.Keywords:CultivationFeeding rateGiant featherbackCaridina sp.Rasbora sp.