Further observations on the fry production of Oreochromis niloticus in concrete tanks

Abstract The effect of prolonged breeding periods (50–72 days) on the fry production of Oreochromis niloticus broodfish stocked at 347 g/m 2 with a sex ratio of one male to two females in concrete tanks was determined. Total fry production after two periods was assessed. Higher average fry production (16.2 fry m −2 day −1 ) was obtained following the peak breeding period compared with that (9.0 fry m −2 day −1 ) after the final breeding period.