Influence of light indicators on the development of Clarias gariepinus during early ontogenesis

High-quality and fast fish farming is very relevant and in demand nowadays. The african clary catfish is one of the representatives of aquatic organisms, which makes it possible to study complete embryogenesis in a short time in order to understand what favorable environmental conditions are necessary to obtain a larger volume of marketable fish. The aim of our study is to study the early stage of ontogenesis of Clarias gariepinus under the influence of changes in the degree of illumination of the environment. The material for the study was eggs obtained from females at the age of 2 years. The incubation was carried out on special mesh trays located on the surface of the pools. A total of 91000 eggs were laid for incubation. The eggs were fertilized by artificial insemination. The fertilized eggs were kept at an optimum temperature of 28,5°C. The first group was incubated in the dark, and the second under fluorescent lamps. Every 5-15 minutes, eggs were placed in a Petri dish and the material was counted and photographed using a digital camera.
The results of our research showed that 20 minutes after fertilization, the onset of blastodisc formation was recorded in both groups. After 35 minutes, cell cleavage begins. The duration of this period is considered from the moment of cleavage until the complete overgrowth of the embryonic disc with cells. After 80 minutes, further division of the embryonic cell occurs with the formation of a spherical structure - morula, as well as the overgrowth of the yolk with the embryonic layer. Later 15 hours, after fertilization, we found that the development of the embryo occurs evenly, with positive dynamics, regardless of illumination.
An analysis of the results obtained allows us to conclude that changes in light parameters do not have a negative effect on the rate of development of the Clarias gariepinus eggs.

1. Vlasov VA Influence of light on the growth and development of fish / V. A. Vlasov, N. I. Maslova, S.V. Ponomarev, Yu.M. Bakaneva // Bulletin of the Astrakhan State Technical University. Series: Fisheries. - 2013 (2). - S. 24-34. URL: https://cyberleninka.ru/article/n/vliyaniesvetana-rost-i-razvitie-ryb.

2. Kryzhanovsky S.G. Ecological groups of fish and patterns of their development / S. G. Kryzhanovsky // IZV Pacific. Research Institute of Fish. households and oceanography 1948. - T. 27. -S. 3-114.

3. Kryuchkov V.N. Morphology of organs and tissues of aquatic animals / V.N. Kryuchkov., G.M. Abdurakhmanov, N.N. Fedorov. // Moscow: Nauka, 2004 .-- 144 p.

4. Russ T.S. Methodological guide for the collection of eggs, larvae and fish fry / T.S. Russ, I.I. Casanova // VNIRO - M .: Food industry, 1966 .-- 43 p.

5. Ruchin AB Influence of the characteristics of light on the development, growth and physiological and biochemical parameters of fish and amphibians / A. B. Ruchin: author. dis. ... Dr. biol. sciences. Saransk, 2008.52 p.

6. Vlasov V. A. Vosproizvodstvo i vyrashchivanie klarievogo soma (Clarias gariepinus) v ustanovkakh s zamknutym vodoobespecheniem (UZV) [Reproduction and growing of catfish in reservoirs with the closed water supply]/ V. A. Vlasov// Razvitie akvakul’tury v regionakh: problemy i vozmozhnosti. Doklady Mezhdunarodnoi nauchno-prakticheskoi konferentsii VNIIR, RASKhN. Moscow, Izd-vo RGAU-MSKhA, 2011. - P. 67-72.

7. Kilambe R. V. Influence of temperature and photoperiod on growth, food concumption and food conversion efficiency of connel catfish / R. V. Kilambe, J. Nobe, С. E. Hoffman // Proc. 24 th Annu cons. Southeust Assoc. Game and Fish Commis., Atlanta ga 1970. - S. J. 971. - P. 519-531.