Reproductive Aging of African Catfish in Aquaculture

Abstract

The work is devoted to the study of reproductive aging of African catfish in the conditions of industrial aquaculture. The problem is urgent, because industrial aquaculture changes the biology of African catfish so much that it loses its ability to reproduce naturally. The offspring of African catfish can be obtained only with the use of hormonal inducers of gametogenesis. Questions of age selection of producers and age composition of breeding stock in this type of fish are still open. In practice, we have to face the facts of poor quality of sexual products in primary spawning or old females and males. The aim of the study was a comparative assessment of age-related variability of reproductive properties of female and male African catfish in the conditions of industrial aquaculture. The results of our study showed the presence of age-related dynamics in the quality of sexual products in African catfish. Age-dependent differences in the quality and fertilization of eggs, the viability of embryos and larvae, their size, and the quality of offspring were established. When studying the properties of sexual products in fish of different ages, differences in morphometric and physiological parameters were found for a complex of indicators such as the size and diameter of eggs, sperm concentration, and the number of viable spermatozoa. Evaluation of the influence of parents age on the viability of offspring in the embryonic and postembryonic periods revealed that this indicator is the lowest in first – spawning fish, and the highest in middle-aged fish. The Russian Foundation for Basic Research has supported our study with the grant No. 18-416-730005.