Maternal age influences on reproductive rates in Nile tilapia (Oreochromis niloticus)

In this study we examined the effects of the maternal age on the fecundity (absolute and relative), egg production, and fertilization rates of Nile tilapia (Oreochromis niloticus). Females were divided into three groups: Group 1 (6 years old), Group 2 (3 years old), and Group 3 (8 months old). Males of eight months were used in all groups. Twice a week, the females' mouths were examined, and if they had eggs, these were removed and transferred to 2-L incubators. No difference was observed in the absolute fecundity between the different maternal age groups. Relative fecundity and egg production was greater in Group 3 (8 months) and fertilization rates were lower in Group 1 (6 years). Younger tilapias are more viable for egg production, because they have better reproductive indexes.

本研究探究了母本年龄对尼罗罗非鱼（Oreochromis niloticus）的绝对繁殖力、相对繁殖力、产卵量以及受精率的影响。将雌性尼罗罗非鱼分为三组：第1组（6龄）、第2组（3龄）及第3组（8月龄）。所有实验组均采用8月龄的雄性个体作为父本。每周对雌性尼罗罗非鱼的口腔进行两次检查，若其口腔内含有鱼卵，则将鱼卵取出并转移至2-L孵化箱中孵化。不同母本年龄组间的绝对繁殖力无显著差异。第3组（8月龄）的相对繁殖力与产卵量更高，而第1组（6龄）的受精率更低。幼龄尼罗罗非鱼更适用于产卵生产，因其具备更优异的繁殖性能指标。