Effects of Water Temperature on Sex Differentiation and Growth Parameters of the Mozambique Tilapia (Oreochromis mossambicus, Peters, 1852)

In this study, the effects of water temperature on growth, survival rate, gonad development and sex ratios of Mozambique Tilapia (Oreochromis mossambicus) were studied by applying different temperature applications (28, 30, 32, 34 and 36oC) for a single period of 40 days. At the end of the study, in the control group (28oC), the males proportion was 47.62%. In fishes reared at 30oC, average male ratio was found as 73.68%. The highest male proportion was obtained in the 36oC temperature group (86.67%). Growth performances, feed utilization and gonad development were found to increase with elevating temperatures up to 34oC unlike the survival rate which has been found to fall with higher temperatures. In this study, sex differentiation rates differed significantly between all groups (p<0.05). However, the highest male rate obtained in group A and D. As hypothesized, results suggest that fish performed better at 30-32°C than 28°C or 34-36°C water temperature and the optimum temperature for a better expression of growth parameters in Mozambique Tilapia could be 30oC.