Experimental works on factory reproduction of tench (Tinca tinca L.) in the Saratov region

Currently, the practice of artificial reproduction of tench in fish farms is extremely limited. This is based on the lack of effective methods of its factory reproduction. The purpose of our research was to develop biotechnical elements that optimize artificial reproduction of tench in the conditions of the Saratov region. The objects of research were producers of tench caught in the Volgograd reservoir by water nets. In total of 25 specimens were caught and pre-planted in trays tench producers, including 15 specimens females weighing from 750 to 1555 g and 10 specimens males — from 673 to 1055 g. Two schemes were used to stimulate puberty in female tench with the acetonated pituitary gland of the carp. The first group of females was injected with pituitary solution twice: a preliminary dose of 0.6 mg/kg; allowing — 6 mg/kg of body weight with an interval between injections of 12 hours. The second group of females was injected once with a pituitary dose of 15 mg/kg. The best indicators in the production of ovulated oocytes were shown by females who were injected twice, and in this group an additional second portion of a small amount of eggs was obtained. Male tench were injected once with a pituitary dose of 3 mg/kg. According to the time of injection, the males were divided into two groups: the first group was injected with the pituitary gland simultaneously with the pre — injection of the females; the second — at a resolution. The best results in terms of ejaculate volume were obtained in the first group (0.5–0.6 ml). From the second group of males, the volume of seminal fluid was 0.3–0.4 ml. Methods for the desticking of fertilized eggs using the proteolytic enzyme alkalase and tannin are investigated. The proteolytic enzyme showed a well-defined decongestant activity, but during the incubation of eggs, the shells of shell eggs burst and at the time of hatching single instances of larvae were observed. More stable results on hatching of larvae were obtained with the use of tannin, as a degumming substance.

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Innovative Biotechnology of Artificial Reproduction of Fish Populations

Vestnik APK Verhnevolzh`ia ◽

10.35694/yarcx.2020.51.3.003 ◽

2020 ◽

Author(s):

П.Е. Гарлов

Keyword(s):

Pituitary Gland ◽

Sea Water ◽

Natural Populations ◽

Ecological Factors ◽

Water Supply Systems ◽

Artificial Reproduction ◽

Fish Farms ◽

Commercial Fish ◽

Fish Breeding ◽

Critical Salinity

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.

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