Farag, M. (2003). REPORODUCTIVE PERFORMANCE OF OREOCHROMIS NILOTICUSTHROUGH THREE SEASONS IN EARTHEN PONDS. Egyptian Journal of Aquatic Biology and Fisheries, 7(4), 263-282. doi: 10.21608/ejabf.2003.1794
Mohamed Farag. "REPORODUCTIVE PERFORMANCE OF OREOCHROMIS NILOTICUSTHROUGH THREE SEASONS IN EARTHEN PONDS". Egyptian Journal of Aquatic Biology and Fisheries, 7, 4, 2003, 263-282. doi: 10.21608/ejabf.2003.1794
Farag, M. (2003). 'REPORODUCTIVE PERFORMANCE OF OREOCHROMIS NILOTICUSTHROUGH THREE SEASONS IN EARTHEN PONDS', Egyptian Journal of Aquatic Biology and Fisheries, 7(4), pp. 263-282. doi: 10.21608/ejabf.2003.1794
Farag, M. REPORODUCTIVE PERFORMANCE OF OREOCHROMIS NILOTICUSTHROUGH THREE SEASONS IN EARTHEN PONDS. Egyptian Journal of Aquatic Biology and Fisheries, 2003; 7(4): 263-282. doi: 10.21608/ejabf.2003.1794
REPORODUCTIVE PERFORMANCE OF OREOCHROMIS NILOTICUSTHROUGH THREE SEASONS IN EARTHEN PONDS
Genetics Department, Central Laboratory for Aquaculture Research, Abbassa, Agricultural Research Center, Egypt.
Abstract
Reproductive performance of Oreochromis niloticus broodstock was examined in earthen ponds through three spawning seasons in Sedy Salm City, Kafer Al-Sheikh Governorate. 21 thousand females (65-150 g) and 10.5 thousand males {75-200 g) were randomly assigned to 10 ponds (750 m ) at a density of 600; 700 & 800 females and 300; 350 & 400 males per pond. Fish were exposed to different levels of water temperature ranging from 20.04 °C to 36.06 °C during the three spawning seasons.Oreochromis niloticus began to lay eggs at water temperature 20.06 "C. Spawning percentage increased during April; May and June were 23.82; 30.05 and 20.61 % at water temperature 20.04; 26.26 and 34.75 °C in three seasons respectivialy. During May, 2000, 2001 & 2002 female gave high number of fries /.m2/ day ; 7.85±1.73 ; 6.84±1.16 and 7.85±2.03 fries / m2 /day, respectivialy. Also, high female relative fecundity were 1.25±0.41; 1.76±0.24 and I.3±0.34 fries/g female body weight at three season, respectivialy. On the other hand, high fry production per spawn per female was 184.6i53.01; 149.26i31.87 and 143.26±25.37 fries / female, when water temperature was 20.04; 26.79 and 26.26 °C, respectivialy.It is evidant that the reproductive performance of Oreochromis niloticus could be maximized by holding broodstock under natural photoperiod in water temperature above 20°C, the optimal reproductive performance occurs through summer season during May. The optimal water temperature range was 28-31 °C and females with highest body weight started to spawn first and gave more total fries.