Abstract:
The study assessed the best immersion period and concentration of different plant extracts (water-leaf and aloe vera) that can efficiently remove egg adhesiveness of Clarias gariepinus. One male and a female C. gariepinus broodstock weighing 1.0kg and 1.3kg, respectively were used for the experiment. All the breeding procedures for C. gariepinus were carried out. Three different concentrations, 1%, 3% and 5% of the plant extracts were used. 2g of urea diluted in 4g Nacl/L of water was used as reference de-adhesion agent, while water without urea solution nor plant extracts was used as control. The fish eggs were rinsed with the solutions at different durations of 1, 3 and 5 minutes. Each concentration with the rinsing time was done in duplicates. All percentage data were
subjected to multivariate Analysis of Variance test and Tukey test was used as a follow up procedure. Third order Polynomial regression analysis was used to determine the best concentration and immersion period that removed egg adhesiveness of C. gariepinus. The results of the study showed that there were no significant differences (p>0.05) in the percentage non-adhesive egg and hatching of eggs immersed in Aloe vera gel and Urea solution. The number of non-adhesive egg and hatching increased in waterleaf extract and was significantly different (p > 0.05) from Aloe vera gel but not significantly different from urea solution. Therefore, this study showed that waterleaf extract at 1%
concentration and 1minute immersion period can efficiently remove egg adhesiveness and increase hatching in C. gariepinus.
