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  • Development of technology of sauce from regional raw materials with the addition of pectin

    Brazhnaya, I. E.; Chernyavskaya, A. S.; Sudak, S. N.; Bykova, A. E. (2018-09-30)
    The production technology of sauce from cranberries and apple pectin has been described. The characteristics of the main raw material have been considered. The results of marketing researches of assortment of sauces, realized in large trading networks of Murmansk, technological scheme and a recipe of cowberry sauce with addition of apple pectin have been presented. The properties of pectin and its effect on the consistency and organoleptic characteristics of sauce have been studied, and the effect of citric acid on the color palette of finished products has been established. To search for a composition close to the optimal composition of the sauce, the method of planning the experiment has been used with the processing of results by the nonlinear regression method using the computer program Datafit 9.0. The results of the determination of the amount of ascorbic acid and the dynamics of the vitamin C content during storage in a cooled and frozen shocked ready-made sauce by the method of direct iodometry have been presented. It has been established that in the frozen product vitamin C is kept better than in the cooled product, the use of a portion of fresh sauce in an amount of 30 g covers 11 % of the daily physiological rate of vitamin C intake. The amount of pectin substances has been determined using the gravimetric method in the prepared sauce and raw materials. The amount of pectin substances in cowberries is 0.31 %, and in the finished sauce – 4.94 %. The comparative analysis of the obtained results with normative documents has been given. The influence of ultraviolet irradiation on the microbiological parameters of the finished product during storage has been studied. The results of microbiological studies of the sauce before and after ultraviolet irradiation have been presented. The bactericidal effectiveness and the volume bactericidal dose (exposure) have been calculated. The time of irradiation sufficient for the death of pathogenic microflora has been calculated. To achieve the required bactericidal effectiveness, the exposure time is 3 seconds. The effect of ultraviolet bactericidal irradiation on the tested products has been studied in accordance with the calculated data, a comparative analysis of the results obtained has been carried out. The approximate shelf life of the cowberry sauce has been stated.
  • Cryoextrusion in technology of fish feed production

    Golubeva, O. A.; Titova, S. A.; Grekov, E. O. (2018-09-30)
    The process of grinding the frozen fish raw materials using the useful model of a piston-type extruder with cooled working bodies has been investigated. A new feed product – cryo minced fish feed – has been obtained. The possibility of replacing the standard manufacturing operations of the defrosting and subsequent grinding of raw materials by one operation of cryoextrusion has been justified. Planning of the experimental part has been performed by the method of combination squares. During the experiment, the volume of samples, their specific surface area, mass, initial and final temperatures of the working chamber, the temperature of raw materials, the temperature of the resulting minced meat, the pressure force, the time of the experiment, the mass of waste have been determined. The rational shape and size of the die holes for the extrusion of raw materials have been determined. It has been found that when using a nozzle with the "hourglass" shape of holes with a diameter of 4.5 mm and 7 mm, the duration of the extrusion process for the studied fish species is 47 to 130 s. The finished product – cryo minced fish feed – has a fairly homogeneous structure and juicy texture, the temperature in the thickness of the product is equal to the temperature of the raw material before its processing (–18 °C). The granulometric composition of the cryo minced fish feed using the sieve analysis has been determined. The statistical processing of the results of experiments to determine the pressure of frozen fish raw material by the method of nonlinear regression has been carried out using the program DataFit version 9.1.32. The regression equation describing the influence of the complex parameter – the coefficient of the hole shape, taking into account the diameter and shape of the matrix hole, and the degree of grinding of raw materials on the force of extrusion has been obtained. The expediency of using the matrix "hourglass" which allows to obtain the lowest pressure force for bony fish of the North Sea basin has been proved.
  • Improving the process of heat treatment of the stingray stellate

    Astramovich, V. L.; Golubeva, O. A. (2018-09-30)
    The results of developing a method for combined blanching (water – steam) of a stingray stellate have been presented. The proposed method completely excludes the process of preliminary wetting and, as a consequence the hydration of stingray meat; allows one to get a semi-finished product suitable for further processing for culinary purposes, as well as for canning. Analysis of the mass-size characteristics of wings of stingray stellate, caught in the Barents Sea, made it possible to identify a group of raw materials with a specific surface area 0.2560 ± 0.05 m2/kg, which corresponds to 75 % of the block weighing 10 kg with an average mass of the sample equal to 161.33 g. The presented experimental setup allows investigating the process of blanching with water, steam or a combined method of raw materials of both plant and animal origin. To plan the experiment, the combinatorial squares method has been applied. The effectiveness of urea removal from the stingray stellate meat has been confirmed experimentally by comparing the mass fraction of carbamide in muscle scate tissue before and after preliminary heat treatment accounting the characteristics of the product under study. The developed mode of combined blanching (water – steam) for stingray is characterized by an effective removal of urea (42.5 %) and can be used for industrial blanchers of processing lines. The mathematical model of the duration of steam treatment depending on the water temperature and the duration of water treatment, makes it possible to predict the regime of preliminary heat treatment of raw materials.
  • Enzymatic conversion as a method of producing biologically active peptides

    Agarkova, E. Yu.; Kruchinin, A. G. (2018-09-30)
    The growth of food products output volume including dairy products enriched by food ingredients with different biological effects is caused by deterioration of socioeconomic conditions, unstable ecological situation and unbalanced nutrition. The basic types of milk proteins proteolysis and the benefit of enzymatic catalysis over alkaline and acid have been considered. The data relating to usage of milk proteins hydrolysates in different fields of specialized and medioprophylactic nutrition depending on degree of hydrolysis and molecular weight of peptides have been presented. The substrate specificity of enzymatic preparations used in dairy industry in respect to impart the specified functional properties to milk protein has been analyzed. The impact of free amino-acids content in hydrolysates and the necessity to select enzymatic composition subject to the data relating to amino-acid sequence of protein and ferment substrate specificity has been described. Herewith protein hydrolysate obtaining with acceptable organoleptic properties and predicted biological effects is possible. The investigation analysis in the field of the functional products manufacture using protein containing milk raw material for production of protein compositions with the following creation of products on their basis has been carried out. The possibility to use the strategies of the directed enzymatic hydrolysis on obtaining of peptide compositions possessing hypotensive properties due to inhibition of angiotensin-1-converting ferment (ACF) by short oligopeptides has been demonstrated. Moreover, milk protein hydrolysates contain short peptides possessing cytoprotective and immunomodulatory action. Besides, milk protein hydrolysates exhibited the presence of antioxidant activity regarding different radicals in the systems with lipids oxidation.
  • The enzymatic activity of various organs and tissues of Far-Eastern trepang as a system of indicators of maturation and quality of products

    Pivnenko, T. N.; Pozdnyakova, Yu. M.; Kovalev, N. N.; Mikheev, E. V.; Esipenko, R. V. (2018-09-30)
    The activity, substrate-inhibitory specificity, temperature and pH dependence, seasonal changes in proteolytic and nucleolytic enzyme systems of the digestive tract, muscle and reproductive trepangs tissues have been considered. The different-rule variability of enzyme activity at different stages of development has been shown. At the stage of growth proteolytic enzymes of the intestinal tract have the greatest activity, which is significantly reduced during spawning. In muscle tissue, there are opposite processes associated with changes in the strength. Separation of proteases of the trepang digestive tract by ion exchange chromatography has been carried out. Two peaks of proteins showing trypsin activity corresponding to the isoforms of this enzyme possessing a negative charge have been detected. The molecular weight of the corresponding peaks determined by the electrophoresis method is 26 and 28 kDa. The data obtained are similar to those established earlier for other types of holothurians. Determination of the activity of proteases of trepang muscle tissue in different seasons has shown a low level of proteolytic activity during the growth period. The activity values in acid and neutral proteases are close to each other. The lowest activity has been detected in alkaline proteases. During the spawning period, the activity of acid proteases increases significantly in the muscle tissue, proteolysis remains at the same level in the neutral and alkaline zone. Reproductive tissue processes of growth and formation of the gonad is accompanied by high activity of the acidic deoxyribonucleases. At the stage of spawning it is significantly reduced, in the post-spawning period it is completely absent. Interactions of enzymes with substrates and inhibitors allow preventing the presence of cathepsins, metalloproteases and serine proteases in the trepang intestinal. The reduction of strength of the muscle tissue may be due to the action of metalloproteases affecting on the structure of the collagen matrix. The results are recommended for the development of rational methods of trepang processing by regulating the activity of enzymes.
  • Antioxidant complex extracts from fucus algae of the Barents Sea

    Obluchinskaya, E. D. (2018-09-30)
    A new method for obtaining antioxidant complex extracts from fucus algae has been proposed at the example of three mass species of the Barents Sea: Fucus vesiculosus, Fucus serratus and Fucus distichus. The chemical composition and antioxidant activity of new phytocomplexes has been studied. The high value of the main antioxidants – fucoidan, polyphenols, free amino acids and ascorbic acid – has been shown. For the most important indicators from the antioxidant activity point of view (fucoidan, polyphenols, ascorbic acid), a technological yield has been calculated in terms of the content of BAS in dry raw materials. The use of the new method has made it possible to achieve the most complete extraction of polyphenols and ascorbic acid (over 90 %) from algal raw materials with the simultaneous increasing the percentage of these substances in extracts of fucus algae (25–30 % for polyphenols). The content of fucoidan equal to 50–60 % also advantageously distinguishes the dry extracts obtained by the developed method from the extracts described in the literature. The antioxidant activity of dry extracts of fucus algae has been tested by comparing samples with quercetin, which belongs to a group of plant flavonoids. As a result of the study, a high antiradical activity of all the extracts studied with respect to the DPPH radical has been established. The greatest antiradical activity is characteristic of extracts from the Fucus vesiculosus. The IC50 value (0.035–0.038 mg/ml) has been compared to the IC50 of the quercetin comparison agent (0.026 mg/ml).
  • Conditions of acetic acid producing by Brettanomyces yeast

    Novikova, I. V.; Yuritsyn, I. A.; Muravev, A. S. (2018-09-30)
    Brettanomyces yeast has found their application in brewing (Lambic and Guezze style). Acetic acid obtained during fermentation by Brettanomyces yeast participates in the synthesis of ethers responsible for the taste and aroma component of the beverage. In this study the ability of four yeast strains Brettanomyces (intermedius, bruxellensis, custersianus, and clausenii) to produce acetic acid on a medium containing glucose has been determined. The strain B. bruxellensis has been found to be the most effective for the biological acidification of the medium including brewing. The optimum mode of air output at full consumption of glucose and achievement of maximal values of volumetric equal to 0.06 g/(l*h) and specific yield of acetic acid equal to 0.43 g/(g*h) has been determined, it is equal to 300 l/h. Influence of temperature and mixing of the medium on the production of acetic acid by B. bruxellensis in an environment containing glucose at the temperature of 26, 30, 34 °C and the speed of the mixer 250, 350, 450 rpm has been investigated by statistical methods. The optimal conditions for the maximum volumetric output of acetic acid – 0.114 g/(l?*h) are the temperature 28 °C and the mixer speed 250 rpm.
  • Chinese mitten crab Eriocheir sinensis domesticates a new habitat

    Shklyarevich, G. A.; Kuchko, Т. Yu. (2018-06-30)
    The fact of habitation of an invading species – the Chinese mitten crab Eriocheir sinensis – in the Lakhtinskaya Bay of Lake Onega has been registered. It should be mentioned that the first specimens were caught near the Pukhtinskiy Islands of Lake Onega in 1993, and in 2006 – in the Kondopoga Bay and the Povenets Bay of this lake. In 2017, the detection of the Chinese mitten crab was recorded in the Lakhtinskaya Bay of Lake Onega. The morphometric analysis data of these animals have been given. The obtained data can be used to create an information base of the studied species for further analytical examination of its growth and age, life cycle characteristics and reproduction, nutrition and migration movements, as well as for forecasting the ecological situation.
  • Current trends of breeding and cultivation of non-traditional aquaculture facilities (arctic charr, king crab, sea urchin) and aquatic processing technology

    Makarevich, P. R.; Obluchinskaya, E. D.; Dvoretsky, A. G.; Zhuravleva, N. G. (2018-06-30)
    The analysis of current scientific, technological, regulatory and methodical literature concerning cultivation and biotechnology of non-traditional species of fish (arctic charr) and valuable species of marine invertebrates (red king crab and sea urchin), as well as technology for complex processing of aquatic organisms has been carried out. The modern trends and problems of cultivation and use of these objects have been described. It has been shown that the freshwater form of Arctic charr has been successfully used in aquaculture in many countries while the aquaculture of anadromous (migratory) charr as an object of mariculture is still poorly developed and using this fish in mariculture is still too early. It is possible that in the near future as a result of breeding selection or interspecific crosses some forms with the required properties will be obtained. An analysis of published data suggests that there were no regular maintenance work in Russia on cultivation of sea urchins for obtaining their high-quality products to establish a basis (ingredients) of production for therapeutic and prophylactic purposes. The main efforts of previous studies on aquaculture of red king crab were aimed at the cultivation of larvae and postlarvae and rearing of mature males to reach an appropriate commercial quality. However, it should be noted that the methods of cultivation of crabs aged 3–5 years have not yet been well developed. There is also no information on the availability of accessible and relatively cheap ways to accelerate the molting process in crab, and it is known that just a long period of growing this crustacean (the commercial size is reached at age of 9–10 years) prevents the development of the red king crab aquaculture in a commercial scale. Modern processing of marine aquatic organisms should be based on a comprehensive, non-waste approach of producing traditional foods, therapeutic and prophylactic means and feed for aquaculture. The establishment of such a united technological cycle for processing red king crabs, sea urchins, and arctic charrs is a promising direction of development of the fish processing industry in the Murmansk region.
  • Investigation of olfaction of gray and harp seals by the operant training method

    Litvinov, Yu. V.; Pakhomov, M. V. (2018-06-30)
    The results of studying the possibility of producing a motor conditioned reflex in the gray and harp seals on the smell of an object and the ability of experimental seals to differentiate certain odours have been presented. The study has contained three stages. In the first stage the seals were trained to differentiate a container from the camphor solution from a container with distilled water. In the second – to differentiate the container with a solution of dimethyl sulfide from the container with distilled water. At these stages, the possibility of developing a conditioned motor reflex to the olfactory stimulus in the seals studied has been studied. At the third stage, the ability of experimental animals was examined by paired presentation of a container with the solution of dimethyl sulphide from a container with camphor solution. The experiment has been carried out under the MMBI aquacomplex in the Kola Bay. The experimental animals were two female gray seal (Halichoerus grypus, Fabricius, 1791) at the age of 7 years and two females of harp seal (Pagophilus groenlandicus, Erxleben, 1777) at the age of 2 years. For the experiments, the stimulants were diluted in distilled water to such concentration that the odour intensity was minimal, then the solution was placed in a container. The results of the work have demonstrated the ability of experimental seals to develop a motor conditioned reflex to olfactory stimuli and the ability to distinguish one odour from another. When teaching the differentiation of a container with a smell, the rate of training of gray and harp seal is relatively the same, while learning to differentiate two smells, harp seals are trained an order of magnitude slower than gray seals. This difference in the speed of training is probably due to the specific features of the seals studied and indicates a higher plasticity of the nervous activity of gray seals.
  • Ore mineralization of gold-uranium occurrences Ozernoe and Lagernoe (Kuolayarvi structure, North Karelia)

    Koval, A. V.; Bogachev, V. A.; Petrov, S. V. (2019)
    Alkaline-carbonate metasomatites of fault zones are widely distributed within all Precambrian shields. Their studying has attracted the close attention of researchers in connection with the confinement of various concentrations of ore-forming elements. In addition, a clear structural control of metasomatites, their composition and stages of development are of great importance for the predictive assessment of geological structures. Kuolayarvi zone is one of the most promising in the Republic of Karelia in terms of prospecting, evaluating and possible industrial production of gold and uranium. On its territory, the Mayskoye gold deposit has been identified, as well as a number of complex gold-uranium ore occurrences, among which Ozernoye and Lagernoye are of the greatest interest. This paper discusses the features of the ore mineralization of these ore manifestations, as well as the dependence of its composition on the primary rock that has undergone hydrothermal-metasomatic study. In the general sequence of forming ore minerals, six parageneses (rock, uranium ore, sulphide, selenide-telluride, low-temperature and hypergenic) have been revealed. It has been also established that gold mineralization is associated with the selenide-telluride paragenesis, and uranium – with the uranium ore and low-temperature ones. The interrelation of the ore parageneses with the global stages of the development of the Kuolayarvi structure (Svekofennian and Paleozoic activization) has been shown. New data on the Re-Os isotope dating of sulfide formation minerals (chalcopyrite and molybdenite), with which gold mineralization is closely associated, have been presented. The so-called "chemical" isotope age of uraninite has been calculated as well. The obtained isotopic data allow us to consider that the formation of minerals of the uranium and gold ore formations took place during the period of the Svekofennian activation of the Kuolayarvi structure.
  • Sequence of REE-Th-U minerals in the Litsa uranium ore area (the Kola Region)

    Kaulina, T. V.; Lyalina, L. M.; Il'chenko, V. L. (2019)
    Mineralogical and petrographic study of REE-Th-U mineralization in rocks of the Litsa uranium ore area has been carried out to detail the sequence of formation of rare-earth, uranium and thorium minerals in rocks. The study has been aimed to Dikoe ore occurrence with the earliest in the area REE-Th-U mineralization described by previous workers. Rocks and minerals have been studied by means of optical and electron microscopy, as well as microprobe methods, this has made it possible to identify the relationship of minerals and the sequence of their crystallization. In monzodiorite veins and host biotite gneisses are found accessory minerals represented by monazite-(Ce), uraninite, zircon, apatite, and thorite, which are in close association with each other, but are formed at different stages of formation and transformation of the host rocks. Monazite-(Ce) with high thorium content (9–10 %) in association with apatite grows at the magmatic stage of monzodiorite crystallization both in the veins themselves and after the fine-grained mass of minerals in the biotite plates of the host gneisses. Magmatic zircon with elevated content of thorium and uranium crystallizes in veins together with monazite and apatite. The formation of uraninite, containing impurities of sulfur, yttrium and calcium, and associated with areas of granulation of plagioclase, occurs as a result of hydrothermal-metasomatic processes in veins simultaneously with the formation of textureless zircon rims with high calcium, iron, and hafnium content in the host gneisses. The development of galgenbergite and anglesite rims around uraninite grains reflects the next superimposed hydrothermal processes.
  • Infestation of blue mussels (Mytilus edulis L.) by trematode larvae in various areas of the Murmansk Coast of the Barents Sea

    Kuklin, V. V.; Kuklina, M. M. (2018-06-30)
    A parasitological examination of Mytilus edulis bivalves in several areas of the Murmansk Coast has been carried out. It has been established that blue mussels on the Murmansk Coast are infected by metacercaria trematodes from the families Echinostomatidae and Gymnophallidae; the former being found almost everywhere, and the second infection is noted only for the Ainov Islands region. The values of quantitative parameters of infestation in different regions have been given, the probable causes of the observed differences (taking into account the schemes of life cycles of parasites) have been considered. It has been revealed that the highest infestation of mussels is typical for the areas of large nesting colonies of birds (the Ainov Islands, Rybachy Peninsula) and on wide littoral beaches in the Kola Bay where birds actively feed at low tide. It has been established that the main limiting factors determining the degree of infestation of mussels by larvae trematodes and geographical distribution of invasion foci are the presence in the ecosystems of potential intermediate and final hosts of these helminths and the presence of sustainable ecological links between them. Water salinity and hydrodynamic conditions do not play a decisive role since both mollusks and their parasites have a high tolerance to a wide range of values of these parameters. Parasitism of metacercariae of trematodes in mussels causes negative consequences for the physiology and behavior of mollusks and can cause certain damage at artificial growing of mussels. Recommendations on the areas and conditions for the location of blue mussel plantations on the Murmansk Coast have been given. Preliminary, a parasitological examination of the littoral and sublittoral benthos and ornithological observations in the areas of location of mariculture objects are necessary.
  • Changes in activity of harp seal (Pagophilus groenlandicus) in the spring – summer period in conditions of aviary keeping

    Zaytsev, A. A. (2018-06-30)
    The results of research on changes in active forms of behavior of two representatives of harp seal (Pagophilus groenlandicus Erxleben, 1777) in the spring - summer period in conditions of aviary keeping by analyzing its quantitative characteristics have been presented. Material for this paper was gathered within a series of observations on Murmansk Marine Biological Institute's aquacomplex in Polyarny, 2011. Method of "recording individual behavioral manifestations" was used as the main method of observation. The following characteristics have been used as parameters for assessing animal behavior: the mean duration of apnea, the mean duration of animal being on surface, the number of surfacing per minute, the percentage of being underwater and on the surface from the total budget of time, the percentage of being on platform and resting in water from total budget of time. A comparison has been made between the behavior parameters of each animal, and the individual characteristics of their behavior have been described. The gathered data have allowed us to consider possibility of influence of some environmental factors on behavior of harp seals. The impact assessment has been carried out based on the values of the following factors: temperature of water, temperature of air, wind speed, atmospheric pressure level. The statistical analysis has not revealed any significant dependencies between animals' behavior changes and such factors as atmospheric pressure. The Spearman rank correlation coefficient has shown the presence of feedback between the surfacing rate and the water temperature for both animals, and also a positive connection between the mean duration of apnea and water temperature for one animal and the air temperature for other.
  • Migrations and movements of fish in the system "riverbed depression – river"

    Chemagin, A. A. (2018-06-30)
    The researchers have been carried out in the basin of the Lower Irtysh at the mouth of the River Konda, where there is one of the large wintering riverbed depression; the patterns of distribution of fish in different parts of the river during the period of intensive spring migrations – fish moving downstream and upstream in the "riverbed depression – river" system – have been studied; the direction and intensity of the movements of fish, its size range as in the midstream and in the coastal waters of the watercourse have been established. Migratory fish has been recorded round the clock as they passed through controlled sections of the river by hydroacoustic method using the complexes NetCor. The hydroacoustic survey has been performed simultaneously on different sections of the river in the transverse direction – as the midstream, and in coastal waters. It has been determined that the movements of fish in different areas and in different directions have high values of the correlative connection, indicating a high activity of fish in spring. Numerically, fish predominate migrating upstream. The numerical predominance of fish moving in the coastal zone in comparison with the river site located on the midstream than 2.5 times has been noted. In the coastal area among the up streaming and down streaming migrants, small and medium-sized fish (<20 cm) prevailed, and on the midstream – larger individuals dominated (>35 cm). Cluster analysis confirms the difference between the coastal and midstream zones based on the size structure of migrants. The revealed regularities reflect the mechanism for reducing energy loss and optimal distribution of fish in the river flow during the migration period.
  • Occurrence of sterile North-East Arctic cod individual

    Filina, E. A.; Makeenko, G. A. (2018-06-30)
    Based on histological analysis, cod individuals of older age groups that completely lost their reproductive capacity due to age-related gonads' degeneration have been considered. Such individuals have been found among both females and males. It has been revealed that in the gonads of sterile fish the replacement of gametes with connective tissue is taking place. According to the obtained data, the portion of sterile fish in samples among females of more than 100 cm has reached 2.2 %. The analysed sterile individuals are characterized by the drastically low gonadosomatic index while gepatosomatic index is mostly above the average. The reasons of age related sterility of the Barents Sea cod have not been discovered yet. The main role of age related fish reproductive condition is considered to be linked to hormonal regulation distortion of sexual cycle. Studying the distortion in the cod reproduction resulting in spawning skips or fish sterility is believed to be significant not only in theory, but in practice as well. Mature females' biomass is usually applied as reproductive potential indicator. However, the reproductive disorder leading to spawning skips affects reproductive abilities of the species that should be taken into account while estimating total allowable catches. In order to monitor abundance of sterile individuals of the Barents Sea cod, it has been proposed to add its maturity scale with VII stage for fish without reproductive capacity.
  • Aminoacids composition of muscular tissue of Coregonus lavaretus L. (the Kola Peninsula)

    Mishanina, L. A. (2018-06-30)
    The studies of the protein aminoacid composition and free aminoacids of muscle tissue of different ages of Coregonus lavaretus L. from Lakes Umbozero and Lovozero (the Kola Peninsula) have been presented. The research of aminoacid spectra in separate tissues allows to some extent to evaluate the features of protein metabolism and the physiological state of the organism. Aminoacid composition of proteins has been investigated by high-performance liquid chromatography. Fractional composition of the proteins' solubility has been determined by spectrophotometry. Significant differences in the ratio of bound and free aminoacids of muscle tissue of Coregonus lavaretus L. have been substantiated. It is established that the proteins of the muscle tissue of whitefish from Lake Lovozero have a higher total content of essential aminoacids unlike whitefish from Lake Umbozero. The content of essential aminoacid leucine in the proteins of muscle tissue of whitefish from Lovozero increases significantly, which is associated with an increase in the content of salt-soluble myofibrillar fraction. The content of essential aminoacids valine and isoleucine is significantly lower in Coregonus lavaretus L. of Lake Umbozero compared to Coregonus lavaretus L. of Lake Lovozero. Perhaps the lack of these essential aminoacids will lead to the violation of metabolism in the studied fish from Lake Umbozero. The ratio of alkaline aminoacids to acidic ones in the muscle tissue of whitefish from Lake Umbozero is less than that of whitefish from Lake Lovozero. During whitefish puberty the overall pool of essential free aminoacids decreases, the pool is in inverse proportion to content of protein aminoacids.
  • Morphological development of the digestive system of Atlantic salmon Salmo salar L. in the Umba farm during the endogenous feeding

    Livadina, L. V.; Anokhina, V. S. (2018-06-30)
    The morphological and histological characteristics of the digestive system ontogenesis in hatchery of the Atlantic salmon larvae during the endogenous feeding period have been given. An analysis of a number of articles updating information on modern studies of the digestive system in the early ontogeny of various groups of fish has been carried out. The samples were collected at the Umba hatchery in 2015–2016. The authors have performed morphological and histological analyses of embryos and larvae, histological examination of the digestive system of larvae during the transition to exogenous nutrition, the establishment of biological age at the time of certain events in the ontogenesis of the digestive system. Actual values of the biological age of Umba hatchery larvae, at which they shift to the mixed (580 tau-somite) and exogenous (630 tau-somite) feeding have been determined. The obtained results have been compared with the literature data when development of Atlantic salmon larvae takes place in conditions with controlled temperature. Variation in biological age values, when formation of the digestive system structures takes place, has pointed at the functional and morphological differences in ontogenesis of the Atlantic salmon from natural and artificial water circumstances. Development of the Atlantic salmon larvae after hatching in cold-water conditions (3–4 ?С, the Umba hatchery), sequence of the digestive system structures composition, and establishment of the functional readiness to food assimilation has been shown. In this period the growth rate of larvae has been evaluated. The organs responsible for exogenous feeding have been divided into 3 groups, and analysis of their ontogenesis has been performed. It has been recommended to start exogenous feeding with 15–20 % of yolk in presence, at the biological age of 540 tau-somite, 45–48 days after hatching in our case.
  • Weight growth of different generation of the trout Parasalmo mykiss on Lake Imandra

    Kalinina, N. R.; Anokhina, V. S.; Kravets, P. P.; Tyukina, O. S. (2018-06-30)
    The averaged indicators of the weight growth of four generations of trout at different temperatures in the time interval of the life cycle from the transfer of larvae to cultivation until the fish reaches a portioned commercial weight of 400 g when the first withdrawal of products for sale takes place have been analyzed. It has been shown that fish of different generations passes into the weight category "goods" sequentially, but after reaching different ages, while there is no direct correlation between the terms "generation formation" – "first withdrawal for sale". According to our data the most intensive weight growth of fish has been noted in the temperature range equal to 8–13 °C. An increase in the water temperature in the cages to 15–18 °C has led to a slowdown, and then to the suspension of the accumulation of fish biomass. In cages operating in the area of Kola NPP heated water trout of April generation gains the commercial weight of 400 g in 7–8 months after landing of larvae for cultivation, November trout – after 15 months. Trout of October and January generation reaches commercial weight at 11 and 9 months, respectively. The stretching of timing of biomass accumulation is most pronounced in the autumn generation of trout. It has been found that the greatest increase in weight per unit body (145.1 mg per day) is provided by the trout of the January biological group, the smallest – by the November trout (75.8 mg per day). The energy reserve of heat allowing for differently derived individuals to reach a commodity weight of 400 g, is in the range from 3 320 to 5 300 degree-day.
  • Macroalgae's flora of the Kola Bay (the Barents Sea)

    Malavenda, S. V. (2018-06-30)
    The Kola Bay is the most developed part of the Barents Sea. Benthic phytocenoses of its southern part are well studied, and the Northern ones have almost no modern descriptions. Flora of the Kola Bay has not been revised since the beginning of the XX century. The list of species for the Kola Bay of the Barents Sea has been compiled based on the results of expeditions in 2009–2013. The distribution of species in the areas of the bay has been analyzed. Altogether flora according to our data includes 94 species of algae macrophytes. Species diversity decreases towards the top of the Kola Bay: in the northern knee 87 species have been identified, in the middle one – 75, and in the south – only 24. The largest number of species along one incision has been observed on the island of Toros, at the mouth of the bay, – 51. Kornmannia leptoderma and Saccorhiza dermatodea have been detected as species having conservation status.

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