Purpose. Exploitation of aquatic bioresources in Ukraine was traditionally low. In order to provide the population of Ukraine with high-quality fish products, the task of fish industry workers in the country is to create appropriate conditions for increasing fish catches and improve the organization of labor and material provision at fish farms. Our immediate goal in the work was to identify the areas of reforms in the fish industry, which would ensure the progress in it and would be aimed at attracting investments in aquaculture, establishing fish protection bodies with a qualitative change in their working principles, forming a culture of socially responsible fishing, achieving transparency and openness in the work of the State Agency for Fisheries, as well as improving the efficiency of the functioning of state institutions.
Methodology. The basis of the research is the scientific, statistical and reporting data in the fish industry of Ukraine. The research uses the methods of monitoring and retrospective analysis of recent research and publications.
Findings. The information on the implementation of reforms in the field of fish industry in Ukraine is presented: change of territorial bodies, State Fisheries Agency, fisheries regimes, use of aquatic biological resources, regulatory framework, strengthening of international activities and use of foreign experience. In order to increase the capacity of the fish industry, it is being reformed in the direction of changing its structure, increasing funding, introducing foreign investment and using their expertise.
Originality. The need for reforming the fish industry of Ukraine became highly important. Modern socio-economic conditions require changes in the approaches to the organization of the activity of f groups that are marked by significant technological, economic, organizational, regulatory and legal peculiarities that need to be taken into account in economic processes. In accordance with the need for changes in the fish industry, the importance of reforming the fish industry of Ukraine has become urgent.
Practical value. The materials of the article may be appropriate for using by scientists and fish industry workers.
Purpose. To study the spatial distribution of structural and functional indicators of zooplankton and zoobenthos during the period of maximum development of hydrobiocenosis in the contaminated and conditionally clean sites of the Mokra Sura river being under antropogenic pressure.
Methodology. During the collection and subsequent laboratory processing of zooplankton and zoobenthos samples, we used the standard conventional hydrobiological methods. In order to rank the studied river sites, we used the combined index of the community state (CICS) based on the structural-functional indicators of zoobenthos.
Findings. The research results have shown that the species composition of zoobenthos and zooplankton of the Mokra Sura river included many saprobiontic species such as oligochaetes, chironomids and rotifers, which were developed significantly in some sites under the effect of eutrophication and silt accumulation in the presence of anthropogenic pollution. The above-mentioned processes cause inhibition of the life activity of such filter feeders as mollusks and crustaceans being the most powerful zooplanktonic and zoobenthic agents of self-cleaning. The highest numbers of zooplankton and zoobenthos development were recorded in front of the point of the emergency discharge of right-bank sewage water (stimulating effect of organic pollution) while the lowest numbers were registered near the tire plant (combined effect of both chemical sewage pollution and silt accumulation). In the «Dnipro - Zaporizhzhia highway» site, low numbers of zooplankton development were the result of silt accumulation, whereas the zoobenthos biomass turned out to be the highest due to the intensive development of oligochaetes. Planktonic saprobiontic rotifers dominated in the site located in front of the sewage discharge whereas bdelloid rotifers dominated in the upstream sites of the river. The dominance of planktonic and benthic saprobiontic rotifers caused the highest saprobity indices in these sites. According to CICS index, the sites of 3 km and 2 km upstream from the river mouth were the purest ones as indicated by the greatest development of filter feeding crustaceans and the lowest indices of saprobity compared to the other sites studied. These results indicate a very effective biogenic detoxification and precipitation of toxic substances entering the river in the above-mentioned areas, as well as dilution effects of large water masses from the Dnieper River in the mouth areas of its tributaries
Originality. For the first time, the ecological state of the selected sites of the Mokra Sura River was assessed on the basis of the results of a comprehensive study of the structural and functional indicators of zooplankton and zoobenthos during the maximum development of their hydrobiocenosis.
Practical value. The obtained results can be used for hydroecological monitoring to detect the dangerous ecological state of small rivers and to prevent further degradation of the ecosystems of small rivers as well as for calculation of fish losses caused by sewage water effects.
Purpose. To determine the possibility of performing an express-evaluation of the toxicity of ammonia polluted waters based on ethological parameters of Carassius auratus gibelio (Bloch,1782) with the use «time sampling» method.
Methodology. For biotesting in August 2017, water samples were taken from the Denishevsky reservoir of the Teteriv river and water supply network of the water service company, which were placed in aquaria (10 dm3) and a control and experimental groups of fish were formed according to the following scheme: control group – samples of settled (24 hours) clean tap water; experimental group D-1 – water samples from the Denishivsky reservoir with the total ammonia concentration of 1.5 mg/dm3; experimental group D-2 – samples of settled (24 hours) tap water with the total ammonia concentration of 1.5 mg/dm3. Test-objects were females of C. auratus gibelio, in which the parameters of typical and non-typical motor activity and feeding behavior were determined. Fish were exposed for 12 hours. For both experimental groups, water toxicity indexes were calculated in comparison with the control.
Findings. In the studies, we showed the possibility of using the «time sampling» method for rapid assessment of the toxicity of polluted waters with ammonium concentration of 1.5 mg/dm3 based the ethological parameters of Prussian carp (C. auratus gibelio), which included the instantaneous fixation of the number of individuals preferring one or another act of behavior. It was shown that C. auratus gibelio females reacted on ammonia content by impairing the motor and feeding behavior. Settled tap water artificially pollution with ammonia (group D-2) appeared to be more toxic for fish than water polluted by natural way. Immobilization of individual fish in the group D-1 was 6.60% lower, while their survival rate was 11.11% hogher compared to the group D-1. Unlike fish of the experience groups, fish in the control group exhibited only single untypical ethological acts. The calculation based on the behavioral parameters of Prussian carp females demonstrated mainly medium (group D-1) and high (group D-2) levels of acute toxicity of experimental waters.
Originality. For the first time, the express-evaluation of the toxicity of water with elevated ammonium content (1.5 mg/dm3) was carried out by observing the motor activity and feeding behavior of Prussian carp (C. auratus gibelio) by the «time sampling» method.
Practical use. The results of the study are used for the rapid assessment of the toxicity of water of surface water sources of the Teteriv river.
Purpose. The main purpose is developing effective measures for stocking the Zaporizhzhia (Dnipro) reservoir with valuable fish species by studying the biological and fishery aspects of the formation and exploitation of their commercial stocks.
Methods. During the work, we used the generalized results of integrated hydrobiological studies performed in 2015-2017. Materials were collected in the Zaporizhzhia (Dnipro) reservoir using standard fishing gears for fish sampling. Collection and processing of phyto-, zooplankton and zoobenthos samples were carried out using conventional hydrobiological methods. Calculation of fish seed amounts was carried out using classical fishery and ichthyological methods.
Findings. The status of fish feed supply of the Zaporizhzhia (Dnipro) reservoir and its production potential was determined. Based on the obtained data, we calculated the potential productivity of the reservoir. It was found that the reservoir had certain feed supply reserves allowing large scale stocking with the juveniles of commercial fish species. The recommended amounts of reservoir stocking in 2017 were calculated as follows: 570 thousand 1+ carp (weight 100-130 g); 1560 thousand 1+ silver carp (weight of 100-130 g); 400 thousand 1+ bighead carp (weight of 100-130 g); 220 thousand 1+ grass carp (weight of 100-130 g); 135 thousand 0+ tench (weight of 10-20 g); 83 thousand 0+ pike (weight of 100 g); 83 thousand 1+ pikeperch (weight 100 g).
Scientific novelty. The presented results of the study of the state of fish feed supply in the reservoir allow stocking with the calculated amounts creating the bases of the rational use of aquatic bioresources with the preservation of the productive potential of commercial fish species exploited by commercial fishery in the Zaporizhzhia (Dnipro) reservoir.
Practical value. Stocking the reservoir with fish allows improving the overall ecological status of the reservoir and increasing fish productivity under the conditions of commercial fishery exploitation.
Purpose. To give biological assessment of the commercial stock of tulka Clupeonella cultriventris (Nordmann, 1840) of the Dnieper-Bug estuary system in the conditions of the reduced Dnieper flow.
Methodology. Analysis of the biological state of the tulka stock of the Dnieper-Bug estuary system was performed based on the data on the dynamics of its age structure, linear-weight growth and condition factor. Primary materials were obtained from scientific and commercial catches done during the current century. Field and laboratory processing of the ichthyological materials were performed according to generally accepted methods.
Findings. Current commercial fishery situation in the Dnieper-Bug estuary system is characterized by reduced intensity of tulka harvest. Currently, major fish harvest is concentrated in the Mykolaiv fishing ground.
As a result of continuous underfishing, a gradual growth of the mean weighed age of the tulka stock is observed with the accumulation of maximum groups of the right wing of the age series. At the beginning of the study (2001-2004), when age group was represented by three groups, the nucleus of the population was formed by age-1 and age-2 fish – 95.7%. However, last years, due to an increase in the number of age-4 fish, a reduction in the percentage of modal groups (age-1 and ahe-2 fish) to 76.7% was observed. At the same time, the share of age-3 and age-4 fish gradually increased from 15.8% in 2013 to 23.2% in 2017.
Against the background of a relatively instable age structure, the linear growth and body weight growth rates did not change significantly. The highest variability of linear parameters was observed in age-1 fish. With a mean body length of 40.55±0.53 mm (lim=36.2-45.2 mm), deviations from the modal value (Cv) were 5.10%. With an increase in the age, the linear growth rate decreased and no significant variability was observed.
The highest variability of body weight was typical for age-1 and age-2 fish (Cv=17.42 and Cv=15.92%, respectively). The variability of body weight in fish of the right wing of the age series depended by a stable prevalence of females in the stock structure, which were characterized by more significant fluctuations of mean weight due to differences during sexual gland development.
The condition factor of tulka was high, Fulton’s condition factor values varied from 0.85 to 1.04. At the same time, a gradual growth of the condition factor with an increase in age was observed. The highest variability of the condition factor was typical for age-2 and age-3 fish – Cv=12.8-15.2%.
Originality. The paper contains new as well as updated already existing data on major biological characteristics of the commercial stock of tulka in transformed conditions of fish fauna existence in the Dnieper-Bug estuary system.
Practical value. The obtained results are a scientific basis for rational fishery and optimization of fishing pressure on this clupeid species of the Dnieper-Bug estuary system. Under the current conditions, the provided information is topical from the point of view of the improvement of the trophological status of a valuable fishery water body in the context of the reduction of the level of trophic competition between juveniles of semi-migratory fish species and typical zooplantonivorous species such as tulka, which currently increased its abundance.
Purpose. Paddlefish is commercially important species owing to its biological features and consumer characteristics, namely it produces valuable and delicious fish products, such as high quality meat and black caviar. Consequently, its cultivation under Ukrainian fish farm conditions and further realization in domestic and foreign markets are economically efficient. However, the paddlefish broodstock in Ukraine requires the efficient solution of increasing its productivity, identification and assessment of its genetic variation. Thus, the aim of our study was to develop and implement a multiplex PCR-analysis of paddlefish (Polyodon spathula) for population-genetic monitoring of its artificial broodstocks in Ukraine.
Methodology. A multiplex PCR was used for the study. The multiplex PCR development was performed for four microsatellite DNA markers: Psp12, Psp21, Psp26 and Psp28. Each investigated DNA loci, for which the multiplex PCR was optimized, was selected in such a way that the colored PCR products labeled with fluorescent dye did not overlap the length of the amplified fragments. Evaluation of the multiplex PCR effectiveness and processing of the data were performed by fragment analysis of DNA on the genetic analyzer ABI Prism 3130 (Applied Biosystem, USA). The size of the identified alleles was determined using the "Gene Mapper 3.7" program (Applied Biosystems, USA) and LIZ-500 size standard (Applied Biosystems, USA).
Results. Based on the results of capillary electrophoresis of multiplex PCR products, it was found that the amplified fragments for each of the four studied loci: Psp12, Psp21, Psp26 and Psp28 in one PCR reaction were within the expected size range. Data analysis on the electrophoregram demonstrated that Psp21 had the highest peak intensity at 611 fluorescent units (FU) and the lowest peak intensity at 105 FU was observed for Psp26 locus. In the multiplex PCR after proper interpretation of the data we identified heterozygous allelic variants for Psp12 (218/220 bp), Psp26 (144/146 bp) and Psp28 (256/258 bp). Herewith, the Psp21 locus (150/150 bp) is identified in the homozygous state.
Originality. The optimization was conducted and a multiplex PCR was developed for paddlefish genotyping using microsatellite DNA markers.
Practical value. The obtained results can be used for paddlefish genotyping within selective-breeding programs for artificial reproduction of this fish species.
Purpose. To investigate the state of the liver of wild carp (Cyprinus carpio Linnaeus, 1758) and bream (Abramis brama Linnaeus, 1758) from sites of the Zaporizhzhia reservoir with different human pressures based on histological and cytometric parameters
Methodology.The study was carried out in two zones of the Zaporizhzhia reservoir with different degrees and types of human impact - the lower part, located in the agrarian zone (conditionally "environmentally clean" site), and in the Samara Bay with high content of heavy metals in water. The objects of the study were age-4 bream and wild carp. The fish livers for histological studies were obtained from freshly caught fish (in the spring-summer period) by anatomical dissection. Fragments of organs of 0.3 – 0.5 cm were taken for preservation. For the preparation of histological preparations, the liver tissue was stained with hematoxylin and eosin. The pictures of histological preparations were made with the aid of a digital camera connected to the microscope. Histologic sections were investigated with 40X magnification using a microscope with the Sciencelab T500 5.17 M digital camera.
Findings. Human impact on the hydroelectric system causes signs of hepatocyte hypertrophy and a number of histopathologies in cyprinids in the Samara Bay. The cytometric analysis of the liver showed that the area of hepatocytes in the bay was larger in comparison with the the individuals of similar age from the lower part of the reservoir by 20 and 10% for the wild carp and bream, respectively. In this case, a 14% increase in the small diameter of cells was observed the in hepatocytes of carp, and a 10% increase in large diameter and a 19% increase in nucleus area was observed in bream. The results of the histological invesatigation of the morphological structure of the liver of cyprinids inhabiting the Samara Bay have revealed a number of pathological changes. Fatty liver dystrophy was observed in 37% of bream and 12% of wild carp. The bream liver (2%) had necrotic areas of parenchyma. In the 50% of bream and 25% of wild carp, the initial necrosis stages occurred, which were manifested as changes in the nucleus and cytoplasm. Frequently, karyopicnosis and cariolysis and destruction of cellular integrity were observed, which may indicate on a chronic damage and a progressive pathological process. There were no pathologies in the fish inhabiting the lower part of the reservoir.
Originality. For the first time a cytometric and histological study of the liver of age-4 bream and wild carp from the Zaporizhian reservoir was performed.
Practical Value. The obtained results can be used for the detection of histological biomarkers, the most sensitive to the effect of toxic substances. Fish liver is the most appropriate organ for such researches, since changes in its cytometric and histological parameters are a prerequisite for a number of changes in the metabolism as a separate organ and other interconnected systems of fish organism.
Purpose. To investigate the effect of extreme low water temperatures on morphological and histological parameters of young-of-the-year (YOY) channel catfish (Clarias gariepinus (Burchell, 1822) during wintering at a warm water fish farm.
Methodologu. The study was carried out during fish wintering (October-March) in 2016-2017 in the Pridniprovs’k thermal water tank fish farm (city of Dnipro). Water temperature in tanks was monitored twice a day, the hydrochemical parameters – once a week.
Following parameters were determined in YOY channel catfish: individual weight, body length, Fulton condition factor, survival rate (%). Ichthyopathological studies were performed once a week: color, presence of mucus, any skin damages and the state of gills. For the parasitological analysis, scrubs were taken from the body surface and gills, followed by microscopy. During postmortem examination of fish, special attention was paid to the pathological changes of internal organs.
To evaluate the physiological state of YOY channel catfish during wintering, an analysis of tissue and organ microstructures was carried out with the use of histological sections according to generally accepted methods. The analysis of histological preparations was carried out with the light microscope with 8x and 40x magnification and a photographic digital camera "Sciencelab T500 5.17M" at the DNU Department of General Biology and Aquatic Bioresources. The digital material was processed by statistical methods with the determination of the standard error and Student’s test.
Findings. A pecularity of fish wintering at modern warm water fish farms is a long period of too low water temperatures (3-5oC). The study showed that under these conditions, YOY channel catfish lost up to 76% of their weight. Fulton's condition factor was reduced on average by 40%. The parameter of fish survival during the winter period varied from 51 to 64% depending on the individual YOY weight before wintering. Long-term winter starvation of YOY channel catfish caused damage to the the skin epidermis, limiting the number of epidermal glandular cells that perform the protective function; the muscle fibers destruction and their replacement with the fibrous tissue, disorders of myometers and miosept topography. The exhausted YOY channel catfish had following pathological changes in the internal organs: hepatocyte dystrophy, vacuolation of the bile duct epithelium, exfoliation of the intestinal epithelium, death or fusion of intestinal villi.
Originalitu. The obtained data on microstructural analysis of YOY channel catfish tissues and organs in the conditions of extreme wintering allows identifying the adaptive possibilities of this species to low water temperatures and can be used for scientific adjustment of keeping the channel catfish during winter at warm water fish farms.
Practical volue. The presented results of the scientific work are intended for warm water fish farms, which experience problems with the water temperature regime associated with irregular amounts of warm water discharges from energetic objects. Information on histological changes in the YOY channel catfish body in the conditions of low water temperatures under prolonged action could be used to improve fish feeding before unfavorable wintering.
Purpose. To establish during the spring and summer period the physiologically-biochemical response of fish to the effect of excessive anthropogenic contamination on the indicators of the maintenance of hormones and glucose in their blood plasma, and the possibility of using these indicators to assess the ecological status of the water body.
Methodology. Two Lakes in the city of Kyiv were selected for research, which are characterized by various hydrochemical and toxicological indices. These water objects were Lake Kyrylivske (Opechen Upper) – a water body from the system of Lakes Opechen (polluted by the water body) and Lake Babyne that is on Trukhanov Island (relatively clean Lake, control). Fishing was carried out in the early spring and in the middle of the summer by hook fishing gear. In laboratory conditions, the total content of thyroxine (T4), triiodothyronine (T3) and cortisol in blood plasma of fish was determined by enzyme immunoassay, using commercial T3-EIA, T4-EIA sets (NPL Granum, Ukraine) and DS-EIA-Steroid-Cortisol ("Diagnostic Systems" NGO, Russia) using the Rayto RT-2100C EIA Analyzer. The glucose content was determined by spectrophotometrically glucose oxidase method using standard commercial kits "Filisit-Diagnostika" (Ukraine). Statistical data was processed using the programs Statistica 10.0 and Excel programs from the Microsoft Office suite.
Findings. In the spring, excessive anthropogenic pressure on the Lake Kyrylivske causes an energy imbalance in fish, which causes the deceleration of catabolic reactions in their tissues. In this period, the perch and roach react to the conditions of existence in the Lake Kyrylivske increase in the content of cortisol in the blood compared with fish from the Lake. Babyne, what can be their reaction to excessive anthropogenic stress. Also, during this period, the low content of thyroxin and triiodothyronine in the perch from the Lake Kyrylivske was noted compared with the Lake. Babyne, which is probably caused by changes in the oxygen and temperature regime during spawning.
Increase of thyroxine content in roach from Lake Kyrylivske during the summer period with respect to fish from the Lake Babyne may indicate an increase in the negative effects of toxic substances on the physiological state of fish as water temperature rises. At the perch from the Lake Kyrylivske content of T3 and T4 in 1.19 and 6.22 times, respectively is higher, than that of fish from the Lake Babyne, which is associated with enhanced processes of generating energy in his body, as a result of increased activity of redox reactions, as well as different degrees of oxygen consumption by tissues under complicated conditions of existence.
In the summer, in the roach from the Lake Babyne content of cortisol is 2.05 times higher than that of roach of Lake Kyrylivske, which may be the result of a violation of the mobilization of energy compounds by the organism of this species from the Lake Kyrylivske The content of glucose in the blood plasma of the perch from the Lake Kyrylivske was 10.5 mmol/L in the summer, which is 1.43 times higher than that of fish from the Lake Babyne. Such a buildup of glucose can be a mechanism for counteracting toxic substances in the environment. Decrease of glucose content in roach from Lake Kyrylivske is probably the consequence of increased its utilization to ensure the energy homeostasis of the organism under similar conditions of existence.
Originality. Inter-species and inter-season differences in the content of hormones in perch and roach, which were under the influence of anthropogenic loading on the water bodies of the metropolis, were established.
Practical Value. The obtained results suggest that the characteristics of the thyroxine, triiodothyronine and cortisol content can be characterized by the physiological state of fish, as well as the ecological state of the most water bodies.
Purpose. To study the level of amino acid assimilation from the protein of the combined feed and also to characterize the amino acid composition of proteins in muscles and liver of the brown and rainbow trout in conditions of feeding them with the specialized production combined feed manufactured by Aller Aqua.
Methodology. The total amino acid composition of muscle and liver tissues was determined by ion-exchange liquid column chromatography.
Findings. The amino acid composition of the investigated feed as a whole corresponds to the spectrum of amino acids in the tissues of muscles and liver of the brown and rainbow trout. Both a significant predominance of glutamine and glutamic acid was detected in the liver and in the muscles of fish. Among the essential amino acids in the muscles and liver of the fish studied, the largest share belongs to leucine, arginine and lysine.
Originality. First investigated the effect of artificial feeding with specialized productional fodder «Aller Aqua» on the amino acid composition of tissues of brown and rainbow trout reared in conditions of industrial aquaculture.
Practical value. Currently, studies devoted to a comprehensive assessment of the effect of mixed feeds on growth and development, and in particular on the amino acid composition of salmon fish tissues, acquire particular attention. This work makes it possible to investigate the degree of assimilation of protein components of the artificial feed for rainbow trout and discuss the perspectives of the adjustment of the imbalance and deficiency of amino acid composition in the feed.
Purpose: To assess the state of the immune system of brood carp, which were fed with a combined feed containing a liposomal preparation with vitamin E and organic compound of selenium microelement during pre-spawning period.
Methodology: The study has been performed in three experimental ponds, in which carp females and males were placed after wintering. The first experimental group was fed with a diet supplemented with vitamin E at a concentration of 50 mg/mg of the feed and selenium – 0.3 mg/kg. The second experimental group received the supplement of vitamin E at a concentration of 100 mg.kg and selenium – 0.3 mg/kg. The control group received the mentioned combined feed without addition of the vitamin-mineral supplement. After termination of 30-day pre-spawning feeding with the combined feed supplemented with vitamin E and selenium, blood samples for biochemical tests were collected from fish of the control and both experimental groups.
Findings. It was found that pre-spawning feeding of carp females and males with combined feeds supplemented with the above mentioned vitamin-mineral additive had a positive effect on the contents of T-, B-lymphocytes and their subpopulations in fish blood.
Originality. The effect of the liposomal preparation with vitamin E and microelement Se fed to brood carp during the pre-spawning period on the contents of T-, B-lymphocytes and their subpopulations in fish peripheral blood was studied for the first time.
Practical value. The results of the study can be used in fish breeding centers and full-system fish farms for balanced feeding of brood fish.
Purpose. Forming a thematic bibliographic list of publications on certain issues of African catfish (Clarias gariepinus) biology and cultivation in Ukraine and abroad, as well as concerning the effects of rearing conditions on physiological, biochemical and fish-breeding characteristics of clariids.
Methods. The complete and selective methods were applied in the process of the systematic search. The bibliographic core have been formed with the publications in Ukrainian, Russian and English 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 112 sources covering the time interval from 1978 to 2017, as well as an article from the "Aquaculture" journal, dated 2018, and including the fish-biological characteristics of African catfish as representative of Siluriformes order, Clariidae family. 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 covers the questions of cultivation and study of the biological features of African catfish.