Age at sexual maturity and its relationship to longevity in the male annual cyprinodont fish, nothobranchius guentheri

Abstract

Aging was studied in the male, annual Cyprinodont fish, from East Africa, Nothobranchius guentheri. Median life-span of the population was 14 months at 21–25°. It was observed that there was variability in the onset of sexual maturity. When the population was divided into early and late maturing fish, it was found that at 15 months of age, 100 per cent of the late maturing and 34 per cent of the early maturing fish were alive. While the factors determining the onset of sexual maturity are not yet apparent, the presence of subgroups of varying longevity within a relatively short-lived fish population may provide a model system for studying aspects of the aging process.