Purpose. To determine the heavy metal content in abiotic components (water and bottom sediments of tanks), feeds, organs and tissues of rainbow trout in the conditions of industrial aquaculture.
Methodology. The materials for the study were 1+ rainbow trout cultivated in 2011–2012, which were produced from brood rainbow trout reared in the tank aquaculture farm “Ishkhan”. Experimental fish were collected from rearing tanks №№ 3–4. Mean fish weight was 466 g with mean fork length of 36 cm. Fish stocking density at the final stage of rearing was 50 kg/m3 or 100 fish/m2. Fish were kept according to standard salmon culture methods. Quantitative determination of heavy metal concentrations in water, bottom sediments and fish were performed by direct suction of solution in propane-butane-air flame with the aid of absorption spectrophotometer S-115-M1.
Findings. The results of the performed studies include the determined ecological state of rearing tanks and quality of marketable rainbow trout of the fish farm “Ishkhan” by the above-mentioned characteristics.
Main hydrochemical parameters, which characterized water quality, complied with aquaculture norms. However, a tendency for an increase in heavy metal content was noted in bottom sediments. In particular, an increased content of copper, nickel as well as toxic elements – lead and cadmium was observed.
Originality. First study of the ecological state of rearing tanks of the fish farm “Ishkhan”.
Practical value. The obtained results of the ecological state of rearing tanks of the fish farm “Ishkhan” will allow crating optimum conditions for fish rearing.
Keywords: hydrochemistry, heavy metals, bottom sediments, rainbow trout.
Purpose. To investigate qualitative and quantitative indicators of the development of phyto-, zooplankton and macrozoobenthos. To assess bioproductional capacity and potential fish productivity of the Dnieper reservoirs at the current stage of development (2011–2013).
Methodology. The materials were collected across the entire area of the reservoirs according to standard net-station. Collection and processing of the materials were carried out based on generally accepted hydrobiological methods.
Findings. The current state of fish forage resources and productional capacity of Dnieper reservoirs based on the development of phyto-, zooplankton and macrozoobenthos has been investigated. Qualitative and quantitative indicators of the development of phyto-, zooplankton and macrozoobenthos for 2011–2013 have been shown. During the study period, total production varied from 5 to 15 thousand kg/ha that can ensure the potential fish production in the reservoirs of approx. 21–62 kg/ha. It was found that zooplanktonic and macrozoobenthic communities play the predominant role in forming the fish productivity in the reservoirs even with their low level of development. The value of the potential fish productivity in the reservoirs is formed of 14–60% by zooplanktonic communities, 3–23% by soft zoobenthos production, 21–51% by mollusks, and 9–33% by phytoplanktonic communities.
Originality. The qualitative and quantitative indicators of the development of phyto-, zooplankton and macrozoobenthos and to assess potential bioproductional capacity of the Dnieper reservoirs at the current stage of development (2011–2013) have been investigated.
Practical value. The obtained results offer an opportunity to assess the productional capacity of the Dnieper reservoirs and can be used for the development of scientifically sound background for stocking them with commercially valuable fish species for their rational exploitation that is a priority task of fisheries science.
Keywords: reservoirs, phytoplankton, zooplankton, macrozoobenthos, forage resources, production, potential fish productivity.
Purpose. To analyze scientific sources on the studies of toxic and lethal concentrations of pesticides on phytoplankton, zooplankton, zoobenthos and fish in current conditions of Ukraine.
Findings. A review of works of a variety of scientists showed that pesticides with different chemical origins have disastrous effects on everyone without the exception of freshwater biota organisms. The article highlights the peculiarities of the toxic effects of pesticides of major chemical groups, which are used or stored in Ukraine. Their toxic and lethal concentrations for the major species of phytoplankton, zooplankton, zoobenthos and ichthyofauna reservoirs are considered. The data on basic features of behavioral reactions of aquatic organisms on poisoning by pesticides are provided. The basic structural and systemic diosrders of homeostasis of the organisms of aquatic biota are described. The effect of pesticides on phytoplankton needs further research, however, is was found that they have common feature as the disturbace of photosynthesis process and accumulation. In turn, this provoques kills in water bodies and poisoning of phytoplanctivorous fish. Zooplanktonic organisms are highly sensitive to pesticides; hence they can be used as an indicator of the state of fresh water. It was found that, pesticides depending on their concentration have different toxic effects on zooplankton organisms. The effect of pesticides on benthic organisms was little investigated. It is known that benthic communities respond to the presence of pesticide by changes in species composition, number of species, abundance and biomass of benthos in general and individual taxonomic groups of benthic invertebrates. The toxicity of pesticides for fish depends on their chemical nature, the form of the preparation, dose, fish species and age, water temperature and the content of oxygen and salts. In particular, juvenile fish are much more sensitive to the chemicals, and an increase in water temperature and a decrease in oxygen content results in an increase in pesticide toxicity.
Practical value. The array of the generalized information on the toxic and lethal effects of pesticides will be important for scientists who investigate the biological risk of pesticides and their impact on basic categories of freshwater biota and, in general, for ichthyological and environmental research. The information on the peculiarities of the toxic effects of pesticides on fish is important in the conditions of increasing demand for fish products as a source of valuable proteins for humans.
Keywords: freshwater bodies, hydrobionts, phytoplankton, zooplankton, zoobenthos, fish, pesticides, fungicides, molluscicides, algicides, biopesticides, organochlorines, organophosphates, highly toxic compounds.
Purpose. To determine the optimum fingerling body weight during the process of young-of-the-year paddlefish (Polyodon spathula Walbaum) rearing. To adapt the existing technologies of young-of-the-year paddlefish rearing to conditions of southern Ukraine.
Methodology. An experiment aimed at determining the optimum fingerling body weight when rearing young-of-the-year paddlefish have been conducted in ponds of the Dniprovsky sturgeon hatchery and six variants have been provided, where fingerling weight ranged from 0.3 g to 0.8 g, stocking density was 1.5 thousand fish/ha. Physical-chemical and hydrobiological parameters of fish rearing, growth rate dynamics and fish feeding were determined according to generally accepted methods. The results were evaluated based on individual fish weight, mortality, fish productivity, meat accumulation coefficient.
Findings. Average water temperature in ponds during rearing period ranged within 18.4–29.0°. Dissolved oxygen was above 5.79 mg O2/dm3. Average seasonal biomass of zooplankton ranged from 5.39 to 7.37 g/m3. Cladocera played the main role in paddlefish nutrition. Their share in the gut content was up to 90.56%, of them Daphnia sp. composed up to 53.74%.
The analysis of the studies on fish seed quality demonstrated that the weight of fingerlings during fish stocking had significant effect on final parameters of young-of-the-year paddlefish rearing. An increase in fingerling body weight from 0.3 g to 0.8 g results to an increase first of all in survival rate from 12.7% to 29.3% and fish productivity from 39.9 to 120.8 kg/ha. Better mean weight of yearling was obtained when stocking the ponds with 0.8 g fingerlings and was 278 g. Correlation coefficient between fingerling body weight during stocking and mean young-of-the-year weight was within 0.8559, survival rate — 0.9023, fish productivity — 0.9779.
Originality. A scientific assessment, advisability, and possibility for using fingerling of different individual body weight for targeted rearing of young-of-the-year paddlefish have been presented.
Practical value. Optimal body weights of fingerlings during young-of-the-year paddlefish rearing have been determined and recommended.
Keywords: paddlefish (Polyodon spathula Walbaum), survival rate, fingerling rearing, feeding dynamics, fingerling body weight, fish productivity, growth rate.
Purpose. To perform an analysis the fish breeding, biological, productive, exterior indicators of Antoninsko-Zozulenetskiy carps of Ukrainian scaly and Ukrainian framed breeds, their genetic characteristics as well as to provide the methods of the creation of these carps as a selective achievement.
Methodology. The works were carried out in accordance with conventional techniques in fish farming and breeding. Carp breeding was conducted by the method of mass continuously improving selection of fish the aim of which is that a complex of fish breeding and management activities create conditions contributing to the development of productive qualities in the selected carp, while selection and breeding activities form and reproduce the leading pedigree group of the stock.
Findings. In the conditions of the development of fisheries industry, especially important are the problems of selection and breeding works aimed at improving the biological and economic features of fish farming objects by improving the existing and developing new breeds, inbreeding, zonal types, lines, etc., creating a progressive heterotic structure of breeds and forming highly productive pedigree stocks of fish breeding objects.
The main object of commercial fish farming in Ukraine, as in many countries, is carp, so his selection is given much attention.
The starting material for producing the Antoninsko-Zozulenetskiy Ukrainian scaly and Ukrainian framed breeds was carp population of Antoninskiy State fish hatchery (Khmelnytsky region), which was a cross between native carp with mirror Galician carp.
The principal method of carp breeding was a massive, continuously improving selection with high intensity among younger age groups. An importance during the selection was given to the growth rate of the fish, their exterior and constitutional "strength." For the brood, individuals with the highest body weight, scaly cover of which corresponded to accepted standards, beautiful high back constitution and without any signs of defects and diseases were selected. An important role during the selection was also given the distinct manifestation of secondary sexual features in males and females.
The high productive qualities of domestic carp contributed to their spread in the near abroad and far abroad countries as well. They were exported to Russia, Moldova, Romania, China, with the aim of pure breeding and improvement of native carp forms. Based on the analysis of long-term studies on the rearing of Antoninsko-Zozulenetskiy arrays of Ukrainian framed and scaly breeds, it was found that their fish breeding and biological indicators comply with the requirements of the Regulation on testing of selection achievements in animal breeding and can be submitted to the relevant authorities for consideration and approval as a type of inbreeding Ukrainian framed and scaly carp breeds.
Originality. The analysis of fish breeding and biological indicators of Antoninsko-Zozulenetskiy carp of Ukrainian framed and Ukrainian scaly breeds serve as the basis for submission them in the status of inbreed types and approval as a selection achievement.
Practical value. Growing of Antoninsko-Zozulenetskiy carps in production conditions will promote an increase in fish production in ponds and production of marketable fish.
Keywords: breed, interbreed types, carp arrays, fisheries indicators, fish selection, biological indicators, productive characteristics, genetic characteristics of carps, phenotypic characteristics, frequency of allelic variants of loci.
Purpose. To study the effect of feed supplements NUPRO® and BIO-MOS® on the results of rearing the multiple age groups of channel catfish (Ictalurus punctatus Rafinesque).
Methodology. The study of effect of feed supplements NUPRO® and BIO-MOS® on the results of rearing the multiple age groups of channel catfish have been carried out according to conventional methods.
The experiments were conducted in the conditions of Pridneprovsky industrial fish farm of Dnepropetrovsk region. Channel catfish larvae were reared in standard trays. Water volume in trays was maintained at a level of 1.4 m3, stocking density of larvae was 20 thousand fish/tray. Rearing of young-of-the-year channel catfish was conducted in 1 m3 cages, stocking density of grown up larvae was 1000 fish/m3. Age 1+ channel catfish was reared in 1 m3 cages, stocking density was 150 fish/m3.
Findings. The studies demonstrated that feeding of multiple age groups of channel catfish with balanced combined feeds with the addition of feed supplements NUPRO® and BIO-MOS® compared to the control group, which was fed with the combined feed but without supplements, increased their growth intensity. The use of these feed supplements in the combined feed composition contributes to an increase in fish growth rate and fish output and to a reduction in feed costs for fish rearing. The results of the conducted works allow determining the optimum doses of the addition of feed supplements NUPRO® and BIO-MOS® in the composition of combined feeds for feeding multiple age groups of channel catfish reared in the controlled conditions of aquaculture, which are as follow: NUPRO® when added to the feed of channel catfish larvae – 0.5%, young-of-the-year – 3.0%, age-1+ channel catfish – 5.0%; BIO-MOS® for channel catfish larvae – 0.5%, young-of-the-year and age-1+ channel catfish – 5.0%.
Hydrochemical parameters in the experimental ponds were within normal limits, temperature regime was optimal for growth and metabolism in the channel catfish organism.
Originality. For the first time, an analysis of the effect of the use of feed supplements NUPRO® and BIO-MOS® in the composition of combined feeds when rearing the multiple age groups of channel catfish has been conducted and the effect of these supplements on fish culture parameters has been investigated.
Practical value. The use of the feed supplements NUPRO® and BIO-MOS® has been proposed for increasing rearing performance and reduce feed costs when rearing channel catfish,.
Keywords: channel catfish (Ictalurus punctatus Rafinesque), larvae, young-of-the-year, age-1+ fish, feed supplements, probiotics, NUPRO® and BIO-MOS®, fish productivity, feed costs.
Purpose. To investigate the hematological characteristics of blood young-of-the-year carps reared using fish ranching technology in the southern Ukraine and to establish certain correlations between the main fish technical features of the studied groups of the young-of-the-year fish.
Methodology. The studies were based on field and experimental methods adopted for fisheries, biochemical and statistical studies.
Findings. The paper contains the data on mean fish weight, hematological and biochemical parameters of serum of young-of-the-year carps reared using fish ranching technology. Based on a comparative analysis of the obtained data, we detected significant peculiarities and qualitative difference in the absence of foam cells and basophils, which distinguish carp from the group of herbivorous fish, established significant correlations between mean fish weight and hematologic indices of blood. Marked by fish-breeding relationships with signs like weight and some parameters of blood components in all studied fish: hemoglobin in the range from 0.7858 to 0.9943, number of erythrocytes from 0.7843 to 0.9942, lymphocytes from 0.7848 to 0.9949, сholеsterol from 0.7640 to 0.9616 and triglycerides of 0.7499 in silver carp (Hypophthalmichthys molitrix) and 0.9616 in common carp (Cyprinus carpio carpio). To show these relationships graphically, we used regression analysis and the obtained regression equations can give an accurate assessment of the quality of fish seeds through hematological blood parameters and mean weight.
Originality. The analysis of hematological parameters of blood of young-of-the-year carps: common carp (Cyprinus carpio carpio), silver carp (Hypophthalmichthys molitrix), bighead carp (Hypophthalmichthys nobilis), grass carp (Ctenopharyngodon idella) reared using fish ranching technology in the south of Ukraine was performed for the first time.
Practical value. The obtained data allow scientifically recommending them as a component of the indication of the quality and general state of fish seeds. The changes in certain parameters in young-of-the-year cyprinids observed in the process of their growing suggest certain changes in their physiological conditions and may be considered as a specific signal for developing appropriate preventive actions and optimizing fish rearing process.
Keywords: carp family (Cyprinidae), mean weight, hematological parameters, ponds, correlation, regressions.