Open Access
OPTIMIZATION OF STAGES OF PRE-SPAWNING AND SPAWNING PERIODS OF TILAPIA IN COMMERCIAL GROWING
Author(s) -
Ekaterina Vasil'eva,
Irina Melnik
Publication year - 2021
Publication title -
vestnik astrahanskogo gosudarstvennogo tehničeskogo universiteta. seriâ: rybnoe hozâjstvo
Language(s) - English
Resource type - Journals
eISSN - 2309-978X
pISSN - 2073-5529
DOI - 10.24143/2073-5529-2021-3-120-126
Subject(s) - spawn (biology) , aquaculture , production (economics) , fishery , biology , reproduction , fish <actinopterygii> , business , ecology , economics , microeconomics
The article describes the process of commercial fish production in modern aquaculture, which requires high technologies and significant input. Optimization of technological processes while breeding fish is a necessary condition for the development of the industry. It is difficult and virtually impossible to develop a universal production pattern, this is why it is reasonable to split the whole process into several optimization tasks corresponding to each of the stages of the technological cycle. It is proposed to regulate such indicators as the level of feeding, pH value, age of producers as control actions at the stages of pre-spawning and spawning periods. The possibility to use the mentioned parameters for stage optimization, as well as for selecting the best values for each of the factors was assessed. The optimization target is to define the optimal amount of viable eggs, which would correspond to the minimal prime cost. It has been demonstrated that the optimal feeding level for the producers equals to 4 – 4.5 per cent of the fish body weight. The increase in the feeding level influences the fertility of producers insufficiently, inflating the costs. It has been found out that 12 – 24 months old producers have the best reproduction indices. The preferred quality and the vital capacity of spawn received from the producers within this group have also been registered. Another factor which may be used in order to control the process is the pH of water in pools. Regardless of the fact that tilapia producers are relatively undemanding to the habitat conditions and resistant to pH values, it is possible to single out the optimal range of this factor. It corresponds to pH values between 6 and 7.5. This is when the best rates of eggs fertilization and survival are observed.