Effect of temperature and female weight on reproductive performance of two Nile tilapia (Oreochromis niloticus) populations | ||||
| Egyptian Journal of Aquatic Biology and Fisheries | ||||
| Article 3, Volume 15, Issue 2, April 2011, Page 179-193 PDF (108.98 K) | ||||
| Document Type: Original Article | ||||
| DOI: 10.21608/ejabf.2011.2087 | ||||
 View on SCiNiTO | ||||
| Authors | ||||
| Ahmed Fath El-Bab; Mohamed Farag; Ashraf Ramadan; Amal Hassan | ||||
| Central Laboratory for Aquaculture Research, Abbassa, Egypt. Agricultural Research center. | ||||
| Abstract | ||||
| he present study aimed to investigate the effect of temperature and female weight on reproductive performance of Nile tilapia. Reproductive performances of Oreochromis niloticus broodstock from two populations (Kafr Elshiek and Abbassa) were examined in hapas held in concreat tankes through three months (May, June and July 2010) in one spawning season at Abbassa (CLAR). A total of150 females (291.94, 385.68 & 455.68 g) and 75 males (300.148, 300.25 – 300.3 g) from Kafr Elshiek and 150 females (292.5, 387.280 & 456.22 g) and 75 males (300.254–300.44 g) from Abbassa farm were assigned to 6 haps in 2 concrete ponds (75 m2) at a density of 50 females and 25 males per hapa (3x8x1m ie 24 m3 water volume). Fish were exposed to different levels of water temperature ranging from 26.2 oC to 29.6 oC during the three months. The result showed that Nile tilapia begins to give fries at water temperature of 26.2 ± 3.6 oC and the highest reproduction activity in Abbassa population was recorded at the temperature of 26.2 ± 3.6 oC. Female gave maximum average number of fries (3.03 ± 0.59 per gram body weight) in May. While, the reproductive activity was maximum in Kafer El-Shakh population at the temperature of 29.6 ± 2.65oC. Female gave maximum average number of fries (2.99 ± 0.94 fries per gram body weight) in June. The spawning percentage increased during May in Abbassa and kafer El-Shakh (91.63 ± 0.027 & 91.34 ±2.5% respectively) more than other months and the females (400 g) of Abbassa population gave the highest fries number (1025 ± 16.29 fries / female / month) in May at average water temperature of 26.16 oC and air humidity 44.9 %. While, females (300 g) of Kafer El-Shakh population gave the highest fries number (1021 ± 65.28 fries / female / month) in June at average water temperature 29.6 oC and air humidity 47.23%. The highest relative fecundity increased with the decrease in female body weight. Female of Kafer El-Shiek population with w body weight (300g) showed more relative fecundity (5.32±0.218 fries/g body weight) in June. Also, female of Abbassa population with low body weight (300 g) have more relative fecundity (5.24±0.0014 fries/g body weight) in May. On the other hand, female of Abbassa population with high body weight (500 g) have small relative fecundity (1.44±0.42 fries/g body weight) in July. While, female of Kafer El-Shiek population with high body weight (500 g) have lower relative fecundity (2.34±0.22 fries/g body weight) in July. Average number of fry production per spawn was 983 .07±51.5 fries / female for Kafer El-Shiek population in June when water temperature was 29.6 oC. While, average number of fries production per spawn was 979.33±50.28 fries / female for Abbassa population in May when water temperature was 26.16 oC. The result showed that the reporoductive performance of Orochromis niloticus could be maximized by holding broodstock under natural photoperiod in water temperature above 26.16 oC, and the optimal reporoductive performance occures through summer season during May and June. Females with height body weight (400 and 500g) gave fries in first generation age 30 days with high body weight in Abbassa (0.44 & 0.43 g respectively) and females with height body weight (500g) give fries in first generation age 30 days with high body weight in Kafer El-Shiek populations (0.43 g). At the optimal water temperature range from 26 to 29 oC, females with the 300 g body weight started to spawn first and have more relative fecundity than high body weight and water temperature affected merely spawning frequency, but not the number of fries produced per spawn. | ||||
| Keywords | ||||
| reproductive performance; relative and absolute fecundity; Oreochromis; niloticus; Water Temperature; two Populations | ||||
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