Purpose. To determine and analyze structural and quantitative parameters of piscivorous fishes of the Velykoburluts’ke reservoir with the assessment of trophic load on multiple-age juveniles of the silver and bighead carps and their hybrids.
Methodology. Data of the analysis of commercial catches, which were done seasonally during 2017-19, were used as primary materials. The ichthyological material was collected from gill nets catches (mesh size a=30-100 mm). In total, 265 fishes of different species were collected for the biological analysis. The weight of fish preys in stomachs was reconstructed using the empirical equations of the length-weight relationships. Sampling and processing of the materials were carried out according to generally accepted methods. Fish stocks were calculated on the basis of fish mortality rates. The data of official commercial statistics were used in the work.
Findings. The most abundant species of the current piscivorous ichthyofauna in the Velykoburluts’ke Reservoir are pikeperch (estimated stock for 2019 — 26.5 kg/ha), pike (11.7 kg/ha) and perch (kg/ha). The modal range of the pike and pikeperch in the catches was formed by younger and middle age groups, the average length of pikeperch was 35.1 cm, weight - 0.71 kg; pike - 43.6 cm and 0.91 kg, respectively. The most important prey objects of the pikeperch of up to 50 cm in length were bleak (40.7% by the frequency of occurrence and 20.6% by weight of the stomach content), perch (29.6% and 28.7%, respectively) and roach (18.5% and 29.0%); pikeperch longer than 50 cm preyed on roach (57.1% and 36.9%) and perch (42.9% and 17.3%). The food spectrum of pike of up to 50 cm in length was dominated by roach (29.7% by the frequency of occurrence and 22.9% by weight of the stomach content), Prussian carp (respectively 24.3% and 20.5) and perch (16.2% and 12, 5%); that of the pike with a length of 50 cm and more — Prussian carp (45.5% and 22.6%) and bream (36.4% and 31.6%). The main prey objects of perch of up to 20 cm in length were monkey goby (42.9% by the frequency of occurrence and 47.6% by weight of the stomach content) and perch (21.4% and 25.8%, respectively); perch with a length of 20 cm and more — monkey goby (58.3% and 25.8%) and their own juveniles (33.3% and 20.2%).
Juveniles (0+-1+) of the silver, bighead carps and their hybrids were recorded in the stomach contents of piscivorous fishes only in pikeperch with a length of more than 50 cm and pike, their averaged weight share was 8.1 and 0.7%, respectively.
Based on the abundance of piscivorous fishes in 2019, the calculated consumption of 20 g Chinese carps seeds is 17600 ind. that is 51.6% from planned amounts of stocking of the Velykoburluts’ke reservoir.
Originality. Original data on feeding of piscivorous fishes in the conditions of special table fish farm on the middle reservoir have been obtained. The effect of piscivorous fishes on Chinese carps seeds with weights lower than the traditional ones has been assessed quantitatively.
Practical value. The obtained data can be used for the determination of targets of stocking efficiency of the young-of-the-year and yearlings in the case of fish ranching.
Purpose. To investigate the peculiarities of the formation of hydrochemical, hydrobiological regimes and to determine the fish productivity of nursery ponds under a complex exposure to their ecosystem.
Methodology. The work was conducted according to generally accepted hydrochemical, hydrobiological and aquaculture methods.
Findings. The article presents the results of the study on the productivity of nursery ponds when using a complex of intensification measures (fertilization with traditional fertilizers, application of chlorella paste, polyculture, and fish feeding). It was found that the main hydrochemical parameters during the rearing of cyprinid fingerlings were within the standard normal values and were favorable for the development of prey organisms and the cultivation of fish seeds. Positive trends were obtained after the use of chlorella paste when growing juveniles of cyprinids in polyculture with different ratios of common carp and Chinese carps. The use of the chlorella paste in combination with other intensification measures in the experimental ponds created favorable conditions for the development of natural food supplies, growth and survival of cyprinid fingerlings. At the same time, the total fish productivity in the experimental ponds was 22.0-28.0% higher, and the feed costs were 1.1-1.3 times lower than in the control ponds.
Originality. The peculiarities of the formation of hydrochemical and hydrobiological regimes have been investigated and the fish productivity of nursery ponds has been determined using cattle humus and chlorella pasta when growing young-of-the-year carp in polyculture with silver and bighead carp hybrids.
Practical value. The obtained data can be used for developing practical recommendations regarding the optimization of the conditions for growing cyprinid seeds in polyculture using the chlorella pasta, increasing the efficiency of managing the state of aquatic ecosystems and their biological productivity.
Purpose. To investigate the growth characteristics and determine the productivity of paddlefish grown to marketable weight in ponds of the Forest-steppe and Polesia of Ukraine.
Methodology. The cultivation of the North American zooplanktophage, a representative of sturgeons, the paddlefish, was carried out in polyculture with cyprinids in ponds with areas ranging from 0.2 to 74.0 ha with the use of semi-intensive and extensive technologies. The stocking density of age-1-2 paddlefish with an average weight of 86.5 to 1017.0 g varied within 59-150 ind./ha with a total stocking density for all polyculture objects of 515-2402 ind./ha. Intensification measures included application of traditional organic fertilizers into ponds and feeding of carp with feed mixtures based on wastes from the processing of agricultural raw materials of vegetable origin in some ponds. Studies of the intensity of development of the natural food supply of ponds and physicochemical parameters of the aquatic environment were carried out according to the methods generally accepted in hydrobiology and hydrochemistry. The peculiarities of fish growth were studied with the use of common ichthyological methods for the dynamics of body weight gains in absolute and relative values.
Findings. The environmental conditions in ponds during most of the growing period met the biological requirements of the studied aquaculture objects. A periodic decrease in the oxygen concentration in water to 1.5-2.2 mg O2/dm3 was noted, which could have a negative effect on fish growth. The average seasonal biomass of zooplankon in ponds was in the range of 3.8-5.8 g/m3 with predominance of Cladocera and Copepoda. As a result, paddlefish production was 48.8-256.4 kg/ha in total fish production in ponds ranging from 502.3 to 1249.0 kg/ha. Average seasonal weight gain of paddlefish, depending on growing conditions, was 0.84-1.49 kg. The maximum daily increments of this species were observed during the first half of the growing period at a water temperature of 18-25°C, when zooplankton biomass in ponds varied within 3.7-17.4 g/m3.
Originality. New data have been obtained on the peculiarities of paddlefish growth in the conditions of ponds of the Forest-steppe and Polesia of Ukraine.
Practical value. The study results are an integral part of the database for the development of improved sturgeon breeding technologies in Ukraine.
Purpose. Analyze the results of rearing and provide a comprehensive assessment of the productive indicators of male Amur carp of various genesis.
Methodology. The cultivation was carried out in the pond conditions of the Lviv Experimental Station of the Institute of Fisheries of the UAAS. The material for the research was 8- and 9-year-old Amur carp males obtained by the factory method from local females, whose eggs were fertilized with the sperm of local males (local) and defrost sperm of Far Eastern males from the Amur River (cryo). The stocking density of carp breeders in summer was 96-105 ind./ha in winter - 1.0 thousand ind./ha. The maintenance of the producers and the spawning were carried out according to generally accepted instructions. The material was statistically processed in Microsoft Office Excel (2016). The analysis of values is carried out in the system of absolute values. The criteria for analyzing the indicators were their mean value and mean deviation (M ± m), the indicator of variability (Cv). The fish were fed with the specialized food of the firm "Aller Aqua" and sprouted wheat.
Findings. According to the selection and breeding work on the formation of the Amur carp broodstock, it was revealed that the producers raised from the obtained defrosted sperm were characterized by a moderate growth rate and exceeded in terms of the main exterior characteristics of males of the same age of local origin. The average body mass of cryomales aged 8-9 years was 2416.5±295.59 and 2698.0±284.05 g, respectively. In males of local origin of the same age: 2015.0±244.53 and 2277.5±373.09 g, respectively. For the rest of the exterior indicators, the advantage of males obtained using cryotechnology was also recorded.
Originality. A comparative analysis of productive parameters of sexually mature males of Amur wild carp of different geneses was performed for the first time in Ukraine
Practical value. The results of this work will make it possible to carry out a comparative analysis of the complex of productive indicators of sexually mature males of the Amur carp obtained from defrosted and native sperm and to substantiate the expediency of using them in breeding work in order to obtain industrial hybrids.
Purpose. To analyze the peculiarities of lipid metabolism of miexed-bred carp of the first generation from crossing the Antonino-Zozulentinsky and Lyubinsky intra-breed types of Ukrainian frame breed by determining the fatty acid composition of skeletal muscles and hepatopancreas.
Methodology. Experiments were performed to determine the content of fatty acids in skeletal muscle and hepatopancreatic tissues of four groups of fish: two groups of mixed-bred carp of the first generation from crossing Antonino-Zozulentinsky and Lyubinsky intrabreed types of Ukrainian frame breed and two original parental forms of carp.
Findings. It was found that the major amount of fatty acids, which are a valuable energy and plastic material for fish body, was provided by the consumption of natural feeds. Studies of the fatty acid composition of the skeletal muscles of age-1+ carp of different genesis showed that there was some specificity in the accumulation of different classes of saturated and unsaturated fatty acids. Thus, the lowest content in the studied groups of carp had pentadecanoic (C15:0) and lauric (C12:0) fatty acids. The highest concentration in all groups was the content of oleic fatty acid.
Among all groups of fatty acids of total skeletal muscle lipids, palmitoleic acid (C16:1) of the family n=7 was in the lowest amount, which was 0.06 - 0.07 g/kg of body weight. Analysis of the fatty acid composition of the hepatopancreas of the experimental and control groups showed that there was tissue specificity of fatty acid accumulation. Thus, compared to skeletal muscle tissue, there was a significant 2-fold increase in the content of fatty acids in the hepatopancreas.
The lipid saturation index in the skeletal muscle tissue of the studied groups of carp was in the range of 0.136-0.140, which was not a possible inter-group difference.
The total amount of saturated fatty acids in the skeletal muscles of all groups of carp was almost the same. The concentration of fatty acids of local carp of the first generation from crossing the Antonino-Zozulentinsky and Lyubinsky intrabreed types of Ukrainian frame breed was slightly higher compared to the original parental forms.
Originality. For the first time, a study of the peculiarities of lipid metabolism in mixed-bred carp of the first generation from crossing the Antonino-Zozulentinsky and Lyubinsky intra-breed types of Ukrainian frame breed by determining the fatty acid composition of skeletal muscle and hepatopancreas.
Practical value. The study of physiological and biochemical peculiarities of the obtained carp mixes is necessary to confirm the feasibility of their reproduction.
Purpose. Determination of permeability parameters of Prussian carp (Carassius auratus Linnaeus, 1758) spermatozoa membranes for water and cryoprotectants molecules as an important stage in the development of a protocol for their cryopreservation by vitrification.
Methodology. Osmotic response of Prussian carp spermatozoa was studied using photoelectric colorimeter KF-77 (Poland) equipped with a magnetic mixer and thermostated cuvette compartment according to our technique. To determine the permeability of plasma membranes of fish spermatozoa to cryoprotectant molecules, they were incubated in the solutions of ethyleneglycol (EG), 1,2-propanediol (1,2-PD), methanol (Met) of different concentrations, or a mixture of these cryoprotectants prepared with isotonic 0.12 M NaCl aqueous solution. Permeability coefficients of spermatozoa plasma membranes for either water (Lp) or cryoprotectant (Кp) molecules were determined by fitting the experimental dependences of relative cell volumes on time and solving theoretical model equations. The activation energy (Еа) of substance transfer through cell membranes was calculated from lnLp(1/T) or lnKp(1/T), the slope of which was equal Еа/R according to the Arrhenius equation, where R was the universal gas constant.
Findings. It was found that the permeability of Prussian carp spermatozoa membranes to water molecules at 20°С was 3,53±0,18 10-14 m3/Ns, and a decrease in membrane permeability of Prussian carp spermatozoa within the range of 30–18°C was characterized by the activation energy of 48±4 kJ/mol. A decrease in membrane permeability of Prussian carp spermatozoa for cryopotectants within the range of 30–18°C was characterized by the activation energy of 82±5 kJ/mol for ethyleneglycole, 99±7 for 1,2-propanediol and 84±6 for the mixture. This fact indicates that the molecules of the studied substances penetrate into the spermatozoon via passive diffusion through the lipid bilayer. The data obtained can be used to determine the optimal regime of spermatozoa cryopreservation for cyprinids.
Originality. For the first time, the coefficients of the membranes permeability of Prussian carp spermatozoa to water molecules and cryoprotectants (ethyleneglycol, methanol, 1,2-propanediol) and the activation energy of the these molecules transfer through the membranes were determined.
Practical value. The results of the study are used in the development of media and regimes of cryopreservation of freshwater fish spermatozoa.
Purpose. To investigate changes in the biochemical parameters of roach as a species response to the effects of anthropogenic pollution, which is necessary for further biomarking of the aquatic environment.
Methodology. Fish were caught using hook and line fishing gears. Following biochemical parameters of roach were determined: glycogen and lipid contents, activities of lactate dehydrognase, succinate dehydrogenase, ATPase and alkaline phosphatase.
Findings. Changes in some biochemical parameters of roach under the effect of anthropogenic pollution have been found. A lower content of glycogen and lipids (by 68.65 and 16.12%) was detected in fish from a polluted water body (Lake Kyrylivske) compared to fish from the conditional control (Lake Babyne). The active use of reserved lipids and glycogen emphasizes the general deterioration of ecological conditions in the Lake Kyrylivske.
A higher LDH activity in liver and gill tissues (by 25 and 48%) relative to control was found. In contrast, a lower LDH activity (by 11 and 16%) in all studied tissues (muscles, liver and gills) of roach from the polluted water body was detected. Under conditions of pollution of the water body with toxicants of various chemical nature, aerobic redox processes in roach body are intensified as a result of counteracting a potentially aggressive environment. This is confirmed by a higher LDH activity in liver and gill tissues. According to the results of study, a higher alkaline phosphatase activity was also detected in fish from the Lake Kyrylivske (by 39.9 and 24.6%) compared to the control. This indicates an increase in phosphorylation in these tissues, the process of which is aimed at neutralization and excretion of toxic compounds from the body after their detoxification.
The differences between the studied groups of fish in biochemical parameters prove that they live in significantly different ecological and toxicological conditions.
Originality. For the first time, the results of changes in biochemical markers of roach enzyme activity from some water body of Kyiv, which differ in the level of anthropogenic pollution, are presented.
Practical value. The obtained results of the physiological state of roach can be used as a criterion for assessing the ecological status of individual waterbodies, in particular those that are located in urban areas.
Purpose. To analyze the peculiarities of post-stress adaptive changes in the digestive system of sterlet at the micro level in conditions of a recirculating aquaculture system. To investigate the dynamics of changes in the cellular composition of the liver, small intestine and pancreas during the adaptation period. To determine the prospect of using the data of histological monitoring in fish breeding practice in order to assess the morphological and functional status of fish.
Methodology. Primary materials were obtained in the conditions of an experimental private enterprise "Oasis Bisan". Cameral processing of ichthyological samples was carried out in accordance with generally recognized methods and guidelines. Histological studies were carried out using in-house equipment and original techniques specially designed for the diagnosis of fish tissue. The obtained results were processed by the methods of variation statistics using MS Excel with an emphasis on standard errors.
Findings. Microanatomical studies showed that the adaptation of sterlet to the conditions of a recirculating aquaculture system after transportation was 12 days. According to the monitoring results, the most contrasting adaptive changes to new conditions of captivity were noted in the marginal zone of the liver, the small intestine and the pancreas. Under the potential effect of a stress factor, a shift in cell function was noted in the form of shifts in cytological characteristics in the liver. An increase in the linear dimensions of hepatocytes by 1.54 times adequately leads to an increase in the values of the parameters of nuclei by 1.44 times. This is an indicator of a change in the character of intracellular metabolism. Low values of the number of intracellular cavities at the beginning of adaptation are a direct evidence of attenuation of the lipostatic function of hepatocytes. Low values of the “nucleolus/nucleus” diameter ratio (0.40 and 0.41) indicate a change in cellular function in the form of increased glycogen synthesis. During the period of action of the stress factor, the absorption of the components of the chyme in the small intestine occurs with less intensity. Local accumulation of absorbed particles in the cytoplasm indicates a slowdown in digestive processes. After 8 days, under adequate conditions of feeding and maintenance in the mucous membrane of the small intestine, the appearance of goblet glandulocytes can be observed. This fact indicates the normalization of intestinal functioning. The initial period of adaptation practically coincides with the peak of the maximum stress state. At this moment, attenuation of the secretory activity of the pancreas was observed. A significant decrease in the intensity of zymogen biosynthesis leads to the predominance of acinocytes in the volume of the homogeneous pole over the zymogen pole. In the process of adaptation of fish to new conditions of feeding and keeping, acinocytes acquire a specific form. Proteinases and lipases at the end of the secretory cycle of cells exist mainly in an active form and are detected by light-optical methods in the form of a mass of zymogenic granules.
Originality. The paper presents new and significantly updated existing data on the adaptation of sterlet organs and tissues under stress and post-stress adaptation. For the first time, a comparative histological analysis of the structure of the marginal zone of the liver, small intestine and pancreas of age-1+ sterlet individuals was carried out. The information on the taxonomic peculiarities of adaptive changes in the tissue components of the digestive system organs in conditions of a recirculating aquaculture system has been clarified and supplemented.
Practical value. The information obtained is valuable in morphophysiological studies, as well as in fish-breeding practice in connection with the existing modern problem of lowering the vital status of sturgeon broodstock in waters of various origins and purposes. The use of the obtained data makes it possible to qualitatively select fish in order to achieve normal reproductive potential under conditions of a recirculating aquaculture system.
Purpose. To determine the presence of functional changes in the cytometric and biochemical parameters of the blood of Prussian carp of the Samara River under conditions of human impact.
Methodology. The object of the study was age-6 Prussian carp (Carassius gibelio (Bloch, 1782)) of both sexes. The material for the study was collected with the use of gill nets during scientific fishing in the summer-autumn period in 2019. Blood was collected from the caudal vein. Morphological studies of erythrocytes were carried out on blood smears, which were stained according to Romanovsky-Giemsa. Blood smears were studied at 40X magnification using a photomicrograph with a Sciencelab T500 5.17 M digital camera. On the preparations, 150 visual fields were examined. Biochemical studies were carried out on automatic analyzers OLYMPUS AU400 and AU480 from BeckmanCoulter (USA), using BeckmanCoulter reagents. Statistical processing of the data obtained was carried out according to generally accepted methods in MS Excel 2010.
Findings. Age-6 Prussian carp (Carassius gibelio (Bloch, 1782)) of the Samara river, under conditions of anthropogenic impact, were found to have an increase in their glucose content (28.5 - 37.4 mmol/l), as well as an increase in ALT (46.5 - 52.8 U/L) and AST (85.1 - 100.5 U/L) activities in blood that may indicate the formation of certain protective mechanisms for adaptation to the effects of harmful environmental factors. These parameters were highest in specimens caught near Novomoskovsk. Cytometric analysis showed a statistically significant increase in the nuclear weight, the size of erythrocytes and an increase in the nuclear-plasma ratio of red blood cells of fish caught near the village Khashchove and Novomoskovsk. It can indicate the inhibition of the functional activity of erythrocytes. The value of the albumin-globulin coefficient (0.6) and the de Ritis coefficient (1.8 - 1.9) of Prussian carp at all experimental points of the Samara river indicates the beginning of the formation of certain pathological processes in their liver and heart.
Originality. The study of cytometric and biochemical parameters of the blood of Prussian carp of the Samara river of the Dnepropetrovsk region subjected to the significant human impact was performed for the first time
Practical value. The data obtained can be used to conduct hydroecological monitoring of natural water bodies and to determine the degree of the effect of various anthropogenic factors on the health and productivity of commercial freshwater fish species.
Purpose. Forming a thematic bibliographic list of publications on the use of field and laboratory methods for studying the biological and ecological characteristics of fish, the effect of individual indicators on their fishery, methods for assessing the status of ichthyofauna.
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 211 sources covering the time interval from 1946 to 2017, and containing a description of methods for collecting and processing ichthyological material to determine biological, morphometric, and ecological indicators of fish, to study the dynamics of their populations and to predict their catch. 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 ichthyology, pisciculture, fisheries and hydroecology.