The article presents materials on optimizing the conditions for growing pike-perch during the larval period of development in an artificially created environment. The problems associated with the complexity of embryonic and post-embryonic development, the transition of larvae from endogenous to exogenous food, their rearing on artificial feed, and the causes of cannibalism have been described. The goal was to obtain and analyze the results of growing pike-perch larvae in conditions of closed water supply using living organisms as starter feed. The results of a study of the reproduction of pike-perch in industrial conditions of the aqua complex of the Coastal Scientific Expeditionary Base “Kagalnik” of the SSC RAS (Rostov Region, Azov District) are presented, describes the results of rearing pike-perch larvae in a recirculating aquaculture system. The values of the main hydrochemical parameters of the environment in fish tanks, necessary to ensure the normal growth and development of pike-perch larvae, as well as the characteristics of growth and survival during the experiments, are given. As a result, biotechnical standards for the reproduction of pike-perch by the intensive method have been developed. For high survival of pike-perch larvae, it is necessary to ensure timely feeding of larvae – after filling the swim bladder and switching to active feeding. The diet should be varied in terms of species composition of zooplankton. To prevent cannibalism among farmed fish, it is important to maintain the hydrochemical parameters at an optimal level, and the presence of food organisms in the fish tank is also necessary.
The paper considers the functional changes in the reproductive function of sturgeon species of different ages and their hybrids. The dynamics of the development of gonads of females and males during the reproductive cycle is studied. According to the results of studies, it is shown that when the hydrological and hydrochemical regimes of cultivation are stabilized, spawning intervals are reduced, as well as the time of maturity. In this case, the physiological and biochemical status of females at the final stages of maturity is normal, which is confirmed by research results. The development of oocytes in females raised under regulated conditions takes place without any deviations.
The effect of feed with probiotics B-1895 and Subtilis-C on the growth and physiological condition of sterlet producers in the RCD was studied. It was found that the weight gain in the first experimental group was higher by 13.3 % and in the second group by 53.3 % in comparison with the control. A positive effect of the probiotics studied on the stabilization of the physiological state of the fish that experienced little stress at the beginning of the experiment has been revealed. As a result, the normalization of physiological and biochemical parameters with a decrease in blood levels of haemoglobin, cholesterol, triglycerides and beta-lipoproteids is noted. No significant effect of the probiotics studied on the generative function was found. Besides a positive effect of the probiotic «Subtilis-C» on the prevention of oocyte resorption was shown.
The article presents the materials on the current state of aquaculture in Russia and in the world, in particular, the biotechnology of breeding and rearing pike-perch in recirculating aquaculture systems. Pike perch (Sander lu-cioperca Linnaeus, 1758) is in high demand among the population. There are shown the results of artificial production of pike-perch offsprings in the experimental spawning units, which make it possible to create the conditions for spawning close to those in the open water bodies. The work included 3 stages: holding pike-perch breeders and preparing them for spawning; spawning; incubation of eggs and prelarvae hatching. Methods for stimulating and spawning pike-perch breeders, as well as a method of eggs incubation in industrial conditions are described. It was demonstrated that all males matured in 24 hours after injection, females ‒ in 28 hours. Incubation of fertilized pike-perch eggs was carried out in the nests of the spawning device. Fertilization of eggs at the stage of gastrulation made 70%. As a result of research work, there have been selected the optimal hydrochemical parameters and fish-breeding and biological characteristics of farming pike-perch spawners, of intensive incubation of eggs under the controlled conditions of a spawning unit. In addition, there have been registered the infectious, parasitic and alimentary diseases, the alternative ways of cure and preventive treatment have been presented. The results of studying the production of pike-perch offsprings in the experimental spawning unit prove the possibility of its using on the industrial scale. The development of a method for reproducing pike-perch in industrial conditions using a special spawning unit will allow obtaining the viable offspring in the controlled environmental conditions.
The article provides data on the use of a complex preparation, which includes sodium selenite and tocopherol (vitamin E) in the form of injections for sterlet breeders (Acipenser ruthenus Linnaeus, 1758). Obtained data confirm the ability of E-selenium to regulate metabolic processes towards the formation of reproductive tissue by optimizing them. Positive dynamics is manifested during the gametogenesis, in particular, the number of individuals with reproductive cells at the IV stage of maturity is increased.
Lipschütz ulcer is a rare cause of vulvar ulcerous diseases and it is often underdiagnosed, probably because of the lack of knowledge about this diagnosis. The aim of this article is to review the pathogenesis, clinical presentation, differential diagnosis and management of this entity.
1Физиологическое состояние самок севрюги (Acipenser stellatus), выловленных весной на рыболовецком участке в низовьях дельты р. Волги, и самок, содержавшихся на Бертюльском и Лебяжьем осетровых рыбоводных заводах (Астраханская область), оценивали по биохи-мическим показателям крови, которую брали у рыб после гипофизарной инъекции. На каж-дом ОРЗ было выявлено по 2 группы рыб с различным биохимическим статусом. На Бер-тюльском ОРЗ показатели крови у самок группы I были в норме, у самок группы II уровень сывороточного белка, β-липопротеидов, холестерина и гемоглобина в крови оказался ниже в 1,5; 4,3; 1,7 и 1,2 раза соответственно. На Лебяжьем ОРЗ у самок группы II уровень сыво-роточного белка, β-липопротеидов и холестерина был еще ниже -в 1,8; 2,5 и 2,3 раза. У групп самок севрюги с пониженным уровнем концентрации биохимических компонентов в крови выявлено превышение общей бактериальной обсеменённости: на Бертюльском ОРЗ -в 3 раза, на Лебяжьем -в 8 раз. Полученные результаты позволяют говорить о зависимо-сти уровня бактериальной обсемененности от физиологического статуса рыб. Исследование самок севрюги, выловленных весной в низовьях р. Волги, и самок, использовавшихся для рыбоводных целей на ОРЗ, показало, что при примерно одинаковом физиологическом ста-тусе уровень общей обсемененности рыб на ОРЗ был значительно выше, т. е. рыбы в есте-ственных условиях обитания оказались более устойчивыми к инфицированию. Сравнитель-ный анализ физиологического состояния самок и самцов севрюги, выловленных весной в низовьях р. Волги и имеющих примерно одинаковый физиологический статус, выявил, что самки в период нерестового хода имели более высокий уровень общей обсеменённости. Ре-зультаты исследования могут быть использованы для диагностики и коррекции физиологи-ческого состояния осетровых рыб при выращивании в установках замкнутого водообеспече-ния с применением искусственных кормов.Ключевые слова: аквакультура, осетровые, севрюга, производители, физиология, бакте-риальная обсемененность.
To create a theoretical basis for the development of new technologies for the formation of highly productive sturgeon herds, work has begun on conducting research on DNA - markers associated with economically useful traits. At the first stage of the work, polymorphic regions of the mitochondrial DNA (mtDNA) D-loop were investigated in order to search for promising molecular genetic markers associated with the production properties of sturgeon hybrids. Along with point polymorphisms in mtDNA hybrids, variability in the length of the D-loop was observed, as well as the presence of heteroplasmy in length. The length variability of the D-loop is due to the presence of tandem repeating units in multiples of 80 base pairs (bp). Using Fisher’s exact test, it was shown that the proportion of individuals with four tandem repeating units of 80 bp eachsignificantly higher (p = 0.030) in the group of highly productive hybrids. The obtained data suggest that such a trait as the accelerated maturation of female hybrids (A. ruthenus x H. huso) grown in a closed water supply can be associated with the mitochondrial DNA haplotype, in the D-loop of which there are fourrepeating units.
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