Effects of Various Latency Periods on the Fertilization, Hatchability and Survival of Clarias gariepinus

Abstract

The Latency period of post-ovulation of Clarias gariepinus have been demonstrated to affect the viability of its eggs and embryos. This study has examined the effects of various latency periods on the viability of eggs, fertilization, hatchability and survival of the African catfish Clarias gariepinus. Progenies were produced using eggs successively stapped from the African catfish at 10, 12, 14,16,18,20,17,14,21 and 22 hours of post-ovulation. Some eggs and sperm were delayed while others were used fresh. Low survival, hatchability and fertilization rates were observed in treatments 1 and 3, while a fair percentage of fertilization hatchability and survival rates were obtained in treatments 2 and 4. High rates of fertilization and hatchability as well as a considerable rate of survival of progeny after 21 days of indoor rearing was obtained in 14-hour latency period at a temperature of 24.8°C and was significantly different (P<0.05). Therefore, any attempt to improve fingerlings production in Clarias gariepinus must consider the effects of Latency period in relation to water temperature, and the best latency period achieved in this study was 14 hours.