scholarly journals Effect of biofloc system at different salinities and crude protein levels on water quality, growth performance, and survival rate of flathead grey mullet (Mugil cephalus).

2021 ◽  
Vol 0 (0) ◽  
pp. 41-67
Author(s):  
Ashraf Elhetawy ◽  
Alaa El-Dahhar ◽  
Elsayed Elebiary ◽  
Mona Abo El-Wafa ◽  
Ayman Lotfy ◽  
...  
2016 ◽  
Vol 5 (4) ◽  
pp. 13 ◽  
Author(s):  
Daud Kassam ◽  
Marcus Sangazi

<p>Most fish farmers in Malawi culture unimproved fish strains whose growth is slow and mature while still small. Four strains of <em>Oreochromis</em>, namely; selectively-bred/improved <em>O. shiranus</em> (F<sub>8</sub>), two reciprocal F<sub>1</sub> <em>Oreochromis</em> hybrids, and <em>O. karongae</em> as a control (mean weight 2.5 ± 0.7 g) were stocked at a density of 5fish/m<sup>2 </sup>in 9m<sup>2 </sup>hapas replicated three times, and cultured for 90 days at Bunda Fish Farm. Fish were fed twice a day with feed formulated using maize bran and soybean containing 30% crude protein throughout the experimental period. The final mean weights were significantly different (p&lt;0.05) across the treatments whereby; hybrid <em>O. shiranus</em> (male) X <em>O. karongae</em> (female) was 12.09g, hybrid <em>O. shiranus</em> (female) X <em>O. karongae</em> (male) was 9.72g, improved <em>O. shiranus</em> (F<sub>8</sub>) registered 9.23g, and <em>O. karongae</em> was the least with 9.00g. Apparent food conversion ratio was also statistically different (p&lt;0.05) across the treatments whereby; <em>O. karongae</em> was 3.63, hybrid <em>O. shiranus</em> (female) X <em>O. karongae</em> (male) was 3.25, improved <em>O. shiranus</em> (F<sub>8</sub>) was 3.16 and hybrid <em>O. shiranus</em> (male) X <em>O. karongae</em> (female) was lowest with 2.26. There were no significant differences on the water quality parameters across the treatments throughout the experimental period and were within the required ranges for growth and survival of tilapias fish species. The results suggest that <em>Oreochromis</em> hybrids may be suitable candidates for aquaculture in terms of production as they performed better than the improved <em>O. shiranus</em> and the control <em>O. karongae</em>.</p>


2021 ◽  
Vol 47 ◽  
pp. e653
Author(s):  
Fernanda Morais HENRIQUES ◽  
Ariane Martins GUIMARÃES ◽  
Carlos Andrés DÍAZ ◽  
Débora Machado FRACALOSSI ◽  
Edemar Roberto ANDREATTA ◽  
...  

This study evaluated the protein requirement of Litopenaeus vannamei post-larvae during the initial rearing phase in a biofloc system. Five different diets were evaluated with increasing concentrations of crude protein: 31.28, 36.29, 41.57, 46.34, and 51.74 g 100 g-1 CP. Post-larvae (0.16 ± 0.01 g) were stocked at a density of 450 PL m-3 in 400 L tanks. Water quality parameters were maintained within the limits recommended for shrimp farming. After 38 days, a regression analysis revealed that levels of CP content (65.29 – 72.83%), EE (10.45 – 11.65%) and body N (10.45 – 11.64%) increased with increasing protein levels in the diet. A similar trend was observed in the biofloc sludge with respect to CP and N. Survival exceeded 80%, and the shrimp with diets containing 31.28 to 46.34g 100 g-1 CP presented an increase in final weight (1.52 – 2.61 g), productivity (0.69 – 1.10 Kg m-3), weight gain (1.38 – 2.44 g), and feeding efficiency (77.28 – 101.68%), whereas these indices decreased to51.74 g 100 g-1 CP. Crude protein content from 44.26 to 47.12 g 100 g-1 provided the best growth performance during the initial rearing phase of Pacific white shrimp in a biofloc system.


2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Retno Wijayanti ◽  
Muarif Muarif ◽  
Dudi Lesmana

This research was carried out on March to August, 2018, and the experiment on April to June, 2018 at the Fishery Laboratory, Djuanda University Bogor. The objective of research is to know and analyze the survival rate and feed conversion ratio of Giant Gouramy that cultured on biofloc media and different protein levels. The experimental design that used is completely randomized design   with 2 treatments   and 6 replications.  The treatments are  treatment A (feeding of protein level  of 17% + mollase addition  with C,/N  ratio 12) and treatment B (feeding of protein  level  of  30%  without  mollase)  Fish that used is Giant Gouramy fry with length 5-7 cm that maintained cylinder container of diameter 1 m and height 1 m. The results of research that the artificial feeding of protein level of 17% + mollase addition with C/N ratio 12 gives the survival rate which is better, but the feed conversion ratio is bad. The average of the highest survival rate of Giant Gouramy is 89% (treatment A) and the low feed conversion ratio is 1.6 (treatment B). Water  quality during the research are temperature  of  23,6-30,0 °C, dissolved oxygen of 6.4- 8.8 mg/l and  pH of 6,3-8,8.Key words: Giant Gouramy, biofloc, feed conversion ratio, protein level.


2017 ◽  
Vol 25 (3) ◽  
pp. 157-164 ◽  
Author(s):  
Muhammet Altunok ◽  
Osman Özden

Abstract The purpose of the study was to obtain preliminary data on the effect of dietary protein on the growth of the thick-lipped grey mullet (Chelon labrosus) juveniles reared in net sea-cages. The juveniles (6.2 ± 0.61 g) were obtained from the wild and were stocked into net sea-cages at a stocking rate of 100 juveniles per cubic meter and fed with experimental diets including 25, 30, or 35% crude protein for 87 days. The highest mean weight and specific growth rate (SGR) were 39.5 g and 2.13% day−1, respectively, at protein levels of 30%. The diet also resulted in the most efficient feed conversion ratio of 1.61.


Sign in / Sign up

Export Citation Format

Share Document