Comparative study of growth of Nile tilapia, Oreochromis niloticus, male and sex reverted

Abstract

This research aimed to carry out a comparative study of the growth of males and sex reverted males Nile tilapia, Oreochromis niloticus, during the growth phase in intensive culture in an earthen pond of 168 m². Each hapa net of 8 m² was supplied with 20 tilapia. Six control hapa net with male tilapia and six experimental hapa net with sex reverted tilapia were installed. The experiment was designed entirely randomly and each hapa net was considered an experimental unit. The fish were fed commercial extruded ration 4 mm (28% CP), 3 to 4 times a day in rate of 1 to 3% biomass/day. The male group showed initial average weight and length of 152.57 g and 20.60 cm, and the sex reverted group showed values of 155.3 g and 20.81 cm. At the end of the growth phase, the control and reverted fish presented 376.81 g and 27.05 cm and 396.4 g and 27.44 cm, respectively. The average weight increase in the sex reverted fish (237.46 g) was superior to that of the control group (224.29 g). A final average production of 0.87 kg/m² was obtained for the control group and 0.94 kg/m² for the reverted one. The results of the condition factor suggest that food and environment, and consequently the physiological condition of fish were similar between sexed male and sex reverted male tilapia.