AGE DYNAMICS OF REPRODUCTIVE ABILITY AND QUALITY OF AFRICAN CATFISH OFFSPRING UNDER AQUACULTURE CONDITIONS

Abstract

The work is devoted to study of influence of African catfish age on reproductive ability and viability of its offspring. The problem is relevant, since the issues of age selection of producers have developed relatively recently in industrial aquaculture and have not been enough studied yet. As for practical fish farming, specialists often face the problem of low quality of fish gametes that are too young or old enough. The aim of the study was a comparative assessment of the age-related variability of reproductive ability and viability of African catfish offspring. African catfish breeders at the age of 12, 24, 48, 60 months were selected for the research, four experimental groups were formed. The parameters of fertility and the quality of reproductive products, linear and weight growth of the offspring, as well as its viability were studied. The results of the study showed age-related changes in the quality of reproductive products, embryos developing from them, and subsequent larvae. Differences in egg fertility, viability of embryos and larvae, and the size of larvae obtained from producers of different ages were established. All parameters indicate that the parents’ age significantly affects the quality of their offspring. As for study of reproductive products of female African catfish of different ages by a number of parameters, such as size and diameter of eggs, certain differences were established in morphometric and physiological parameters of eggs and sperm. The study of the effect of parental age on offspring survival rate in embryonic and postembryonic periods showed that the offspring survival rate of first spawning females was the lowest and increased as the parental individuals matured. The viability of offspring in middle-aged groups of breeders was the highest.