scholarly journals Reproductive performance of female Nile tilapia Oreochromis niloticus L. in South Kivu (DR Congo): comparison of two strains differing in origin and history of domestication

2019 ◽  
Vol 7 (08) ◽  
Author(s):  
Nihoreye, F.J. ◽  
Nyongombe, U.N. ◽  
Alunga, L.G. ◽  
Akonkwa, B.D. ◽  
Isumbisho, M.P. ◽  
...  
Keyword(s):  
Reproductive Performance ◽  
Oreochromis Niloticus ◽  
Sexual Maturity ◽  
Democratic Republic Of Congo ◽  
Local Strain ◽  
Fish Farming ◽  
Nile Tilapia Oreochromis Niloticus ◽  
History Of ◽  
South Kivu ◽  
Egg Diameter

This study was conducted to evaluate the reproductive performance of females of Oreochromis niloticus originating from a strain of distant origin and extensively exploited in fish farming (Nyakabera strain) and a local strain recently removed from the natural environment (Lac Kivu strain). The experiment was carried out in triplicate with fry of 4.9 to 6.3 g placed in earthen ponds for a period of 6 months, at the Nyakabera fish station in South Kivu, Democratic Republic of Congo. The comparison of the two strains focused on the size of the first sexual maturity, gonado-somatic ratio, fecundity, egg diameter and condition factor. The results showed that under similar managed rearing conditions, the Nyakabera strain reaches sexual maturity earlier and is characterized by a higher gonado-somatic ratio and higher relative fertility, but a worse condition compared to the Lac Kivu strain. These differences, which indicate a better reproductive success of the Nyakabera strain, are related to the origin and the history of domestication, which are just as different from these two strains.

scholarly journals BROODSTOCK SEX RATIO IMPROVES FRY PRODUCTION IN NILE TILAPIA(OREOCHROMIS NILOTICUS) IN NORTHERN SENEGAL

2021 ◽  
Vol 9 (02) ◽  
pp. 72-76
Author(s):  
Mouhamadou Amadou Ly ◽  
◽  
Abdoulaye Ngom ◽  
Ahmadou Bamba Fall ◽  
Ousmane Diouf ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Sex Ratios ◽  
Survival Rates ◽  
Fish Farming ◽  
Commercial Diet ◽  
Ph Values ◽  
Nile Tilapia Oreochromis Niloticus ◽  
Female Survival

This present study was conducted to determine fry production in different male-female sex ratios of Oreochromis niloticusbroodstock in order to improve fry production, which handicapped the development of fish farming in northern Senegal. A total of 180 broodfish (47 males and 133 females) were stocked at a density of 2 fish /m2and was replicated three times for each sex ratio of 1:2, 1:3and 1:4 (male : female). Mean body weight ranges from 136.47±2.13 and 107.27±2.14 g for female and male O. niloticusbroodstock, respectively. The experiment was conducted for 90 days and the broods were fed on commercial diet containing 32% crude protein.Fish were held in 9 rectangular tanks of 30 m3 each (10 × 3 × 1) and half-filled. The results showed that number of fry produced at different sex ratios were significantly different, with sex ratio of 1:2 producing a highest number of fry (279.67) per female, followed by the 1:3and 1:4 treatment recorded the lowest.Broodstock sex ratios also did not affect female survival rates and all treatments had 100% survival rates. Temperature, dissolved oxygen and pH values obtained were suitable for good water quality and normal tilapia reproduction.In conclusion, the results of the present study recommend to stock Oreochromis niloticus brooders when stocked at a density of 2 fish /m2 at a sex ratio of 1 male : 2 female in order to obtain the highest fry production.

scholarly journals Some Spawning Performance Parameters of Cultured Nile Tilapia Oreochromis niloticus, under Brackish Water

2018 ◽  
Vol 7 (1) ◽  
pp. 8
Author(s):  
Nassrin Mashaii ◽  
Farhad Rajabipour ◽  
Mohamad Jafari ◽  
Mohammad Mohammadi ◽  
Habib Sarsangi ◽  
...  
Keyword(s):  
Sex Ratio ◽  
Oreochromis Niloticus ◽  
Stocking Density ◽  
Water Salinity ◽  
Performance Parameters ◽  
Nile Tilapia Oreochromis Niloticus ◽  
Cultured Fish ◽  
The World ◽  
Egg Diameter ◽  
The Impact

Tilapia is one of the most important cultured fish in the world. However, the gap between seed supplies and farmers' demand is one of the serious limitations for tilapia culturists. Notice about different effective agents on tilapia reproduction might be useful for increasing of production and better management of tilapia hatcheries. In the present study, higher efficiency of tilapia Oreochromis niloticus hatchery was considered based on the impact of sex ratio, stocking density, photoperiod, water salinity and replacement period on spawning performance. Sex ratios 1:1, 1:4 and 1:7 (Male: Female), stocking densities 2, 3.5 and 5 fish/m3, photoperiods 6:18, 12:12 and 18:6 (Light:Dark), water salinities  12, 8, 4 and 0 ppt, also10 and 15 days replacement of breeders were studied. Fecundity,breeder and egg per day,spawning intervals, egg diameter and weight were investigated. Results showed stocking density 5 fish/m3, photoperiod 12:12, 8 ppt water salinity and 10 days replacement had better performance. Sex ratio treatments had similar performance.

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