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 Physiological and hematological responses of Nile tilapia (Oreochromis Niloticus) to different anesthetics during simulated transport conditions

2016 ◽  
Vol 38 (3) ◽  
pp. 301 ◽  
Author(s):  
Rodrigo Diana Navarro ◽  
Rafael Paiva França ◽  
Giane Regina Paludo ◽  
Yvonaldo Wlademir Saldanha Bizarro ◽  
Rodrigo Fortes da Silva ◽  
...  
Keyword(s):  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Survival Rates ◽  
Physiological Limits ◽  
Live Fish ◽  
Nile Tilapia Oreochromis Niloticus ◽  
Polyethylene Bags ◽  
Baseline Values ◽  
And Performance ◽  
Higher Doses

Minimization of stress during the transportation of live fish is essential in maintaining the welfare and performance of the animals. In order to test the hypothesis that stress during transport of fingerlings of Nile tilapia (Oreochromis niloticus) can be reduced with the aid of the anesthetics menthol, eugenol or benzocaine, we have assessed the effects of these agents at various concentrations on the physiological parameters and survival rates of fish subjected to conditions simulating those normally used in transportation. Fingerlings (N = 1200) were fasted for 24 hours and distributed in 20 L polyethylene bags (N = 50 per bag) containing 5 L of water and an anesthetic at the appropriate concentration. Fingerlings treated with menthol at 75 mg L-1, or eugenol or benzocaine at 20 mg L-1, maintained levels of plasma cortisol and glucose that were lower than those of the stressed but untreated controls and within the physiological limits of the baseline values for this species. Under these conditions, the survival rate was 100%, suggesting that stress was substantially reduced despite dense consignment. Treatments involving higher doses of the studied agents induced significant anesthetic toxicity. 

Sex ratios in the progeny of androgenetic and gynogenetic YY male Nile tilapia, Oreochromis niloticus L.

Aquaculture ◽  
2004 ◽  
Vol 232 (1-4) ◽  
pp. 205-214 ◽  
Author(s):  
M. Tariq Ezaz ◽  
James M. Myers ◽  
Stephen F. Powell ◽  
Brendan J. McAndrew ◽  
David J. Penman
Keyword(s):  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Sex Ratios ◽  
Nile Tilapia Oreochromis Niloticus

scholarly journals Evaluation of resistance against Streptococcus agalactiae in four farmed strains of Nile tilapia (Oreochromis niloticus)

2020 ◽  
Vol 41 (1) ◽  
pp. 351
Author(s):  
Gláucia Frasnelli Mian ◽  
Charles Oswaldo Roncancio ◽  
Maria Cristina de Souza Silva ◽  
Amanda Carvalho Rosado Ferreira ◽  
Dircéia Aparecida da Costa Custódio ◽  
...  
Keyword(s):  
Fish Species ◽  
Streptococcus Agalactiae ◽  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Survival Rates ◽  
Brain Heart Infusion ◽  
Resistance Test ◽  
Economic Losses ◽  
Control Group ◽  
Nile Tilapia Oreochromis Niloticus

Nile tilapia (Oreochromis niloticus) has always been considered more resistant to diseases compared to other fish species. However, in recent decades, this fish species has also been susceptible to many bacterial, fungal, parasitic, and nutritional diseases. In Brazil, streptococcosis is one of the main diseases that affect tilapia and has caused many economic losses. A resistance test was conducted with 93 tilapia of four varieties (UFLA strain and three commercial varieties: SC1, SC2, and SC3) to evaluate resistance to experimental inoculation with Streptococcus agalactiae. Each variety was distributed in five aquariums, with nine specimens of the same variety. Among the five aquariums, four housed fish were intraperitoneally inoculated with 107 CFU/fish of S. agalactiae and one aquarium harbored fish from the control group, which received 0.1 mL of sterile BHI (Brain Heart Infusion). Significant differences were observed in the survival rates accumulated at the end of the experiment (day 15), with values of 22, 36, 36, and 15% for SC1, SC2, SC3, and UFLA, respectively. The UFLA strain presented lower survival than other strains, which did not differ among the 15 days of challenge. These results demonstrate that there are animals with a better response to the resistance test than others.

scholarly journals A Comparative Study on the Growth, Feed Conversion and Production of Fry of Improved and Non-improved Strains of the Nile Tilapia Oreochromis niloticus

2007 ◽  
Vol 19 (4) ◽  
Author(s):  
M.T. RIDHA
Keyword(s):  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Survival Rates ◽  
Feed Conversion ◽  
Daily Growth ◽  
Nile Tilapia Oreochromis Niloticus ◽  
Fish Weight ◽  
The Gift ◽  
Genetically Improved ◽  
The Mean

Two experiments were conducted consecutively to evaluate and compare the mean weight (MWT), daily growth rate (DGR), feed conversion ratio (FCR), survival and production rate (PR) in the non-improved strain (NS) of the Nile tilapia, Oreochromis niloticus (Cichlidae) with those in the Genetically Improved Farmed Tilapia (GIFT) strain and the FaST selected tilapia (FaST), from the swim-up fry stage to fish weight of 1.0 g (Experiment 1) and from fish weight of 1.0 to 20 g (Experiment 2). In both experiments, results showed the GIFT and FaST strains to have significantly higher MWT, faster DGR, lower FCR and higher PR than those of the NS. Unlike in Experiment 1, survival rates did not differ significantly among the three strains. In Experiment 1, the improvements in the FaST for the MWT, DGR and PR over those for the NS were 77.9, 72.9 and 33.6%, respectively. In Experiment 2, the improvements for the same parameters were 58.7, 57.8 and 54.5%, respectively. These results indicate the advantage and potential of culturing the FaST or the GIFT strain in Kuwait for improving the production of fresh tilapia, reducing the production cost and increasing the profitability of tilapia farms.

scholarly journals Integrated multi-trophic culture of Nile tilapia (Oreochromis niloticus) and Amazon river prawn (Macrobrachium amazonicum) in brackish water

2015 ◽  
Vol 67 (1) ◽  
pp. 265-273 ◽  
Author(s):  
G.G. Henry-Silva ◽  
C.S.P. Maia ◽  
R.S.T. Moura ◽  
A.P. Bessa Junior ◽  
W.C. Valenti
Keyword(s):  
Brackish Water ◽  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Survival Rates ◽  
Stocking Density ◽  
Control Treatment ◽  
Amazon River ◽  
Nile Tilapia Oreochromis Niloticus ◽  
Macrobrachium Amazonicum ◽  
Total Fish

The aim of this study was to assess the feasibility of integrated multi-trophic culture of Nile tilapia (Oreochromis niloticus) and Amazon River prawn (Macrobrachium amazonicum) in brackish water by evaluating its limnological characteristics and economic performance. The experiment was completely randomized with four treatments and four repetitions: control treatment with Nile tilapia only, stocked with 2 tilapias/m² (P2C0) and three integrated multi-trophic culture treatments stocked with 2 tilapias/m² and prawns at densities of 4, 8 and 16 prawns/m² (P2C04, P2C08 and P2C16, respectively). The limnological variables of temperature, pH, dissolved oxygen, turbidity, ammonia, orthophosphate and chlorophyll "a" were evaluated and throughout the experiment remained within the limits recommended for culture. The experiment lasted 150 days with monthly animal sampling. No significant differences were observed for total fish biomass or for fish and prawn total survival rates. However, prawn individual weight decreased as stocking density increased. Gross revenue was not significantly different between treatments, as well as profitability. The profitability was 40.1% (P2C0), 36.7% (P2C04), 41.2% (P2C08) and 50.1% (P2C16). It is concluded that although feasible from the view point of husbandry, the integrated multi-tropic culture of M. amazonicum and O. niloticus did not influence significantly profitability compared to the monoculture system.

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