scholarly journals Morphofunctional assessment of domesticated and aquacultured beluga females

2021 ◽  
Vol 273 ◽  
pp. 03001
Author(s):  
Aliya Akhmedzhanova ◽  
Sergey Ponomarev ◽  
Yulia Fedorovykh ◽  
Olga Levina ◽  
Evgeniy Dutikov ◽  
...  

In the early 80-ies of the last century, there was a sharp decline in the population of the Caspian beluga in Russia. Its fishing was prohibited, except for catching for reproduction and scientific purposes. In the practice of sturgeon breeding, the method of repeated use of sturgeon females and males by obtaining sexual products in vivo, as well as growing breeders in artificial conditions, has become widely put into practice. Against the background of an acute shortage of wild breeders of this sturgeon species, in recent years, the main way to form sturgeon broodstock in the conditions of the Lower Volga region is domestication. However, in recent years, the catches of wild beluga females in the fishing areas of the Lower Volga are estimated as single specimens. The article studies the fish-breeding, biological and physiological parameters of domesticated and aquaculture-bred beluga females. The reproductive function of domesticated and artificially raised beluga females is evaluated. Some proposals for the intensification and priority areas of artificial reproduction in order to replenish natural populations are presented.

Author(s):  
П.Е. Гарлов

С целью повышения эффективности искусственного воспроизводства популяций ценных видов рыб разработаны новые методы управления их размножением, выживаемостью и ростом, которые представлены в виде изобретений. Для управления размножением производителей разработаны методы стимуляции и задержки полового созревания производителей осетровых и костистых рыб. Для стимуляции полового созревания были разработаны препараты изолированной передней и изолированной задней долей гипофиза. Их внедрение в осетроводстве позволило повысить степень их рыбоводного использования в среднем на 15% и достичь экономии гипофиза до 40%. Для задержки полового созревания производителей разработан метод их промышленного резервирования в среде критической солёности 4–8‰, причём как в морской воде, так и в растворах поваренной соли. Производственными испытаниями доказана возможность сохранения рыбоводного качества производителей и получения доброкачественного потомства в этой среде при верхних нерестовых температурах в течение производственно необходимых сроков. С целью заводского воспроизводства природных популяций промысловых рыб разработан метод управления их размножением триадой адекватных экологических факторов ‒ «критической» солёностью, температурой и освещённостью при видоспецифических пороговых воздействиях. На этой основе разработан полносистемный метод воспроизводства популяций ценных видов промысловых рыб (севрюги и Балтийского лосося), охватывающий все этапы заводской биотехники. Новый метод осуществляется путём массовой морской заготовки производителей, получения потомства в морских садках и, после заводского речного выращивания молоди до готовности к миграции, конечного доращивания в морских садках крупной жизнестойкой молоди. Для промышленного внедрения всей предложенной биотехники и круглогодичной аквакультуры разработаны системы водоснабжения рыбоводных заводов и рыбоводных хозяйств на основе внесезонного подземного гидрокондиционирования среды выращивания и на природно-промышленных принципах инженерной экологии. In order to increase the efficiency of artificial reproduction of populations of valuable fish species new methods for managing their reproduction, survival and growth have been developed, which are presented in the form of inventions. To control the reproduction of producers methods have been developed to stimulate and delay puberty of sturgeon and bony fish producers. To stimulate puberty preparations for the isolated anterior and isolated posterior lobes of the pituitary gland have been developed. Their introduction in sturgeon breeding made it possible to increase the degree of their fish farming use by an average of 15% and to achieve a pituitary gland economy of up to 40%. To delay the puberty of producers, a method for their industrial reservation in an environment of critical salinity of 4–8‰ has been developed both in sea water and in solutions of sodium chloride. Production tests have proven the possibility of preserving the fish-breeding quality of producers and obtaining benign offspring in this environment at the upper spawning temperatures during the production required periods of time. With the aim of factory reproduction of natural populations of commercial fish a method has been developed to control their reproduction by a triad of adequate ecological factors – “critical” salinity, temperature and illumination under species-specific threshold effects. On this basis a full-system method of reproducing populations of valuable species of commercial fish (stellate sturgeon and Baltic salmon) has been developed covering all stages of factory biotechnology. The new method is carried out by mass marine harvesting of producers obtaining offspring in sea pens and after the factory river rearing of hatchling until ready for migration the final rearing of large viable juveniles in sea pens. For the industrial introduction of all the proposed biotechnics and year-round aquaculture, water supply systems for fish breeding plants and fish farms were developed on the basis of off-season underground hydroconditioning of the growing environment and on the natural and industrial principles of engineering ecology.


Author(s):  
Adelya Zakirovna Anokhina ◽  
Vyacheslav Fedorovich Zaitsev

Under present conditions of depletion of natural resources and introduction of a moratorium for commercial sturgeon fishing there is a need to take urgent and radical steps in order to conserve the Caspian populations of these valuable species. Natural and artificial reproduction efficiency shall be improved in order to restore sturgeon population level in the Volga-Caspian basin. The analysis of the current state of natural sturgeon reproduction in the Volga river unregulated part has shown that due to a variety of reasons its efficiency has been minimized. The role and importance of artificial reproduction is increasing, yet in the last years its efficiency has been negated because of increasing deficiency of sturgeon sires in natural populations. Timely composition of productive stocks in the fish ponds of 6 Astrakhan region sturgeon breeding hatcheries allows to provide artificial reproduction fish-breeding operations with high quality spawns and milters within the conditions of their population’s decline in the natural habitats. The data on the quantity and the biomass of the sturgeon productive stocks at the Astrakhan sturgeon hatcheries prove that the prospects for developing artificial reproduction are possible only due to using stocks available at the hatcheries.


Author(s):  
E. A. Vertikova ◽  

In a competitive variety trial, promising selection lines of sugar sorghum were studied in the Lower Volga region. Based on a set of signs, the best lines were identified, which are recommended for transfer to the State Variety Testing. Breeding lines, which are distinguished by high values of commercially valuable traits, can be used in planned crosses to create highly productive varieties and hybrids of sugar sorghum.


Sign in / Sign up

Export Citation Format

Share Document