scholarly journals Mathematical modeling applied to the growth of tilapia in net cages in the sub middle of the São Francisco river

2014 ◽  
Vol 34 (5) ◽  
pp. 1001-1011 ◽  
Author(s):  
José de A. de Sousa Júnior ◽  
Marlon da S. Garrido ◽  
Paulo G. S. de Carvalho ◽  
Luciano G. da Rocha ◽  
Daniela F. B. Campeche
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Models ◽  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Nonlinear Models ◽  
Logistic Models ◽  
Point Of View ◽  
Nile Tilapia Oreochromis Niloticus ◽  
Net Cages ◽  
Weight For Age

This study aimed to apply mathematical models to the growth of Nile tilapia (Oreochromis niloticus) reared in net cages in the lower São Francisco basin and choose the model(s) that best represents the conditions of rearing for the region. Nonlinear models of Brody, Bertalanffy, Logistic, Gompertz, and Richards were tested. The models were adjusted to the series of weight for age according to the methods of Gauss, Newton, Gradiente and Marquardt. It was used the procedure "NLIN" of the System SAS® (2003) to obtain estimates of the parameters from the available data. The best adjustment of the data were performed by the Bertalanffy, Gompertz and Logistic models which are equivalent to explain the growth of the animals up to 270 days of rearing. From the commercial point of view, it is recommended that commercialization of tilapia from at least 600 g, which is estimated in the Bertalanffy, Gompertz and Logistic models for creating over 183, 181 and 184 days, and up to 1 Kg of mass , it is suggested the suspension of the rearing up to 244, 244 and 243 days, respectively.

scholarly journals KADAR SENYAWA TOKSIK DALAM DARAH IKAN NILA (Oreochromis niloticus) SAAT MUSIM UP-WELLING DI DANAU MANINJAU, SUMATRA BARAT

2020 ◽  
Vol 38 (1) ◽  
pp. 25
Author(s):  
Silvi Susanti
Keyword(s):  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Common Species ◽  
Toxic Chemical ◽  
Chemical Substances ◽  
Nile Tilapia Oreochromis Niloticus ◽  
West Sumatra ◽  
Phosphate Nitrate ◽  
Net Cages ◽  
Toxic Chemical Substances

Maninjau lake is the largest center for the freshwater floating-net-cage fisheries system in West Sumatra. Every year, during the up-welling season, a huge number of fish suffered to death in the lake including nile tilapia (Oreochromis niloticus), a common species cultivated in the floating-net cages. This current study aimed to determine the factors contributing to the death of fish by measuring the concentration of toxic chemical substances in the blood plasm of nile tilapia as well as in the subtrate collected from the bottom of the lake. The samples were collected in the sites with higher number of floating-net cages as well as higher number of mass death of fish (Tanjung Sani, Pakan Raba’a dan Maninjau) during the up-welling season. The result revealed that the levels of phosphate, nitrate, nitrit, and amonium were higher in the blood plasm of the fish. Moreover, the levels of those chemical substances were also higher in the substrate of the lake. The higher concentration of the toxic chemical substances might contribute to the mass death of fish living in the floating-net cages during the up-welling season.

scholarly journals Extensive Net Cage Culture of Nile Tilapia (Oreochromis niloticus) Fingerlings in Nutrient-enriched Pond

Our Nature ◽  
2013 ◽  
Vol 10 (1) ◽  
pp. 61-70
Author(s):  
W. Jiwyam
Keyword(s):  
Body Weight ◽  
Surface Area ◽  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Supplemental Feeding ◽  
Cage Culture ◽  
Initial Body Weight ◽  
Nile Tilapia Oreochromis Niloticus ◽  
Net Cage ◽  
Net Cages

To investigate the potential of extensive net cage culture for Nile tilapia (Oreochromis niloticus) fingerlings, an experiment was conducted in net cages suspended in a fertilized pond. Mixed-sex population of Nile tilapia with an average initial body weight of 0.065 g was used to stock in experimental cages. Four treatments; non added-substrate without supplemental feeding (NSNF), non added-substrate with supplemental feeding (NSAF), added-substrate without supplemental feeding (ASNF), and added-substrate with supplemental feeding (ASAF) were tested. The results indicated that addition of substrates which gave an additional submerged surface area of approximately equal to the total cage surface area did not show significant effect on the growth (p > 0.05). The fish gross yield obtained from non added-substrate cages without supplemental feeding was 1.22 kg/m3 for a 56-day period.DOI: http://dx.doi.org/10.3126/on.v10i1.7752

The effect of vaccination in controling bacterial disease caused by Aeromonas hydrophila in nile tilapia (Oreochromis niloticus)

2014 ◽  
pp. 27
Author(s):  
Arne A Ratulangi ◽  
Reiny Tumbol ◽  
Hengky Manoppo ◽  
Henneke Pangkey
Keyword(s):  
Survival Rate ◽  
Aeromonas Hydrophila ◽  
Oreochromis Niloticus ◽  
Nile Tilapia ◽  
Bacterial Disease ◽  
Immersion Method ◽  
Nile Tilapia Oreochromis Niloticus ◽  
Different Ages ◽  
Motile Aeromonas Septicaemia

This study aims to apply vaccination against bacterial disease. The purpose of vaccination is to trigger the immune respone both non-specific and specific of fish against bacteria Motile Aeromonas Septicaemia (MAS) caused by Aeromonas hydrophila. The vaccination for fish with different ages: 2-3 weeks and 5 weeks were done using immersion method. The fish were re-vaccinated (booster) after two weeks of the first vaccination. The survival rate was < 50 % for juveniles 2-3 weeks and > 50% for juveniles 5 weeks. Survival rate for juveniles 5 weeks was higher than juveniles of 2-3 weeks. This shows that organs of juveniles of 5 weeks were more complete than the 2-3 weeks juveniles. The age of fish is one of the important factors for successfully vaccination. Penelitian ini bertujuan untuk melakukan penerapan vaksinasi terhadap penyakit bakterial. Vaksinasi ditujukan untuk merangsang respon kekebalan non- spesifik dan spesifik pada tubuh ikan terhadap penyakit Motile Aeromonas Septicaemia (MAS) yang disebabkan oleh bakteri Aeromonas hydrophila. Vaksin diberikan pada benih ikan nila yang berbeda umur yaitu 2-3 minggu dan 5 minggu dengan menggunakan metode perendaman. Ikan divaksinasi ulang (booster) setelah 2 (dua) minggu dari vaksinasi yang pertama. Prosentase kelangsungan hidup < 50 % untuk benih umur 2-3 minggu dan > 50% untuk benih umur 5 minggu. Jumlah kematian benih umur 2-3 minggu lebih tinggi dari 5 minggu. Hal ini menunjukkan bahwa fungsi organ benih umur 5 minggu telah lebih lengkap dari pada benih umur 2-3 minggu. Umur ikan merupakan salah satu faktor penting penentu keberhasilan suatu kegiatan vaksinasi.

Effect of low temperature on genomic DNA methylation in Nile tilapia (Oreochromis niloticus)

2013 ◽  
Vol 37 (10) ◽  
pp. 1460 ◽  
Author(s):  
Huaping ZHU ◽  
Maixin LU ◽  
Zhanghan HUANG ◽  
Fengying GAO ◽  
Xiaoli KE ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Low Temperature ◽  
Oreochromis Niloticus ◽  
Genomic Dna ◽  
Nile Tilapia ◽  
Nile Tilapia Oreochromis Niloticus
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