Reproductive performance of female Nile tilapia under different environments and age classes

Abstract

The objective of this work was to verify the reproductive performance of females Nile tilapia in different age classes and reproductive environments. The data set was composed of 451 females evaluated in two different environments in Maringá, PR (hapas of 10 m³, place 1 and hapas of 1 m³, place 2) and in one environment in Alfenas, MG (place 3). The females were separated into three age classes, corresponding to animals with 1 (age 1), 2 (age 2), and 3 years old (age 3). The spawning verification was performed once a week in the period of October/2012 to March/2013, corresponding to 23 weeks of evaluation. The statistical analyses were performed using the Proc Genmod from the statistical program SAS. Place 2 showed the lowest results compared to the other places for multiple spawning, spawning frequency, and volume of eggs/female using animals of age 2. Statistical differences were not observed between ages 1 and 2 considering the same assessment place; however, the age 3 presented at the place 3 showed superior results than females of age 2. Therefore, avoid the use of animals in individual hapas and maintain older females in the squad can improve the reproductive results.