scholarly journals Dextrose as carbon source in the culture of Litopenaeus vannamei (Boone, 1931) in a zero exchange system

2017 ◽  
Vol 43 (3) ◽  
pp. 526-533
Author(s):  
Sabrina M. Suita ◽  
Eduardo L.C. Ballester ◽  
Paulo C. Abreu ◽  
Wilson Wasielesky Jr.

This work compared the use of dextrose and molasses as carbon sources for biofloc development, water quality maintenance, microorganism composition and growth performance of Litopenaeus vannamei juveniles in biofloc technology (BFT). Two treatments, dextrose and molasses, were tested with four replicates each. Carbon was added to achieve a C:N-AT (N-(NH3+NH4+)) ratio of 6:1. Physical and chemical water quality variables were monitored daily, and shrimp growth was estimated through periodic biometry. After 30 days, survival, final biomass, and feeding conversion rate (FCR) were determined. Dissolved organic carbon, chlorophyll-a, floc volume, total ammonia, nitrite, nitrate and phosphate concentrations, and microorganisms (qualified by groups), were measured every three days. Water quality variables remained within acceptable levels throughout the experimental period, except for nitrite, which reached higher levels than recommended for this species. The use of dextrose resulted in higher water transparency, which influenced the remaining centric diatoms. A superior shrimp performance was observed at this treatment, presumably because of variations on the microbial community. Therefore, it is concluded that the addition of dextrose results in a superior growth performance of L. vannamei when cultured in BFT systems.

2021 ◽  
Vol 93 ◽  
pp. 102159
Author(s):  
Yan Shin Lim ◽  
P. Ganesan ◽  
M. Varman ◽  
F.A. Hamad ◽  
Sivakumar Krishnasamy

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>


2017 ◽  
Vol 39 (5) ◽  
pp. 601
Author(s):  
Davi De Holanda Cavalcante ◽  
Francisco Roberto Dos Santos Lima ◽  
Vanessa Tomaz Rebouças ◽  
Marcelo Vinícius do Carmo e Sá

The present study aimed to assess the possible beneficial effects of the integration between bioflocs and periphyton to the Nile tilapia’s water quality and growth performance. There were four treatments with five replicates each: (1) Control: green waters, (2) Periphyton: substrate-based system, (3) BFT: bioflocs technology for aquaculture, and (4) Biophyton: integration between bioflocs and periphyton. Fish (1.63 ± 0.07 g) were reared for 10 weeks in twenty 250 L outdoor tanks. Two polyethylene boards were vertically set out in the Periphyton and Biophyton tanks as underwater substrates. The C: N ratios of water in the BFT and Biophyton tanks were adjusted to 15:1 with dry molasses applications. The concentrations of total ammonia nitrogen were higher in the Control and Periphyton tanks than in the BFT and Biophyton ones. On the other hand, the concentrations of reactive phosphorus were higher in the BFT and Biophyton tanks than in the Control and Periphyton ones. The fish final body weight, specific growth rate and fish yield have not differed between the tanks. The integration between bioflocs and periphyton has not brought clear benefits to tilapia culture on water quality and growth performance.  


2019 ◽  
Vol 18 (06) ◽  
pp. 14-22
Author(s):  
Tu P. C. Nguyen

The present study evaluated the effects of stocking density on water quality parameters, growth performance and survival rate of white leg shrimp Litopenaeus vannamei, reared in fiberglass tanks, without water exchange. Three stocking densities (50, 100 and 200 shrimp/m2) were tested. Each treatment consisted of three replicates fiberglass tanks (500 L). The shrimp were fed ad libitum four times per day with a commercial pellet (40-42% protein). After an 8-week trial, concentrations of nutrients in the culture tanks showed an increasing linear relationship with increasing stocking density. The growth performance of shrimp in low stocking densities was significantly greater than that in high stocking densities. The results from this study demonstrate that with increasing the stocking density the production of shrimp increased but in a low final weight and survival compared to low stocking density.


Author(s):  
Md. Golam Sajed Riar ◽  
Nur- A Raushon ◽  
Sumit Kumer Paul

Growth performance and survival of Tor putitora fry under different stocking densities were evaluated fry rearing system. The experimental period was 10 weeks from 31 December to 10 March 2019. The experiment was carried out in nine earthen ponds of 0.04 ha each under three treatments with three replications.  Thirty days old fry were stocked at the rate of 1.0X105/ha was designated as treatment- 1 (T1), 1.5X105/ha` as treatment- 2 (T2) and 2.0X105/ha as treatment- 3 (T3), respectively. Fry were fed with commercially available nursery feed containing 32% crude protein. It was observed that, lower stocking density showed highest daily weight gain in T1 (growth 0.066 ± 0.006 g/day) compared with higher stocking density in T2 (growth 0.044 ± 0.004 g/day) and T3 (growth 0.024 ± 0.003 g/day), respectively. It is also noticed that, the lower stocking showed the highest survival rate (79.66 ± 4.34 %) than the other two treatments (66.97±3.67 and 54.67± 3.12 %). The values of different water quality parameters were within the optimum ranges for the rearing of carp fry. Water quality parameters did not show significant variations in the experimental ponds under different stocking densities. Among these three stocking densities lower stocking density (T1) showed the best result compare with the other two higher stocking densities.


Water ◽  
2021 ◽  
Vol 13 (24) ◽  
pp. 3584
Author(s):  
Yiming Xue ◽  
Li Li ◽  
Shuanglin Dong ◽  
Qinfeng Gao ◽  
Xiangli Tian

This study investigated the effect of different carbon sources on water quality, ammonia removal pathways, the bacterial community, and the production of Litopenaeus vannamei in outdoor culture tanks. Three systems were established: a clear water system (CW) and biofloc technology (BFT) systems with added molasses (M-BF) or poly (3-hydroxybutyric acid-co-3-hydrovaleric acid) (PHBV) (P-BF). The average pH, total alkalinity, total organic carbon, biofloc volume, chlorophyll a, nitrite, nitrate, total nitrogen, and nitrification rate were significantly different among the treatments. Microbial composition varied and different dominant taxa were identified in the treatments by linear discriminant analysis effect size. Redundancy analysis indicated that the water quality parameters affected the distribution of the microbial community. Moreover, the genus Leucothrix was closely related to the M-BF treatment. Chemoheterotrophy and aerobic chemoheterotrophy were the most abundant functions in all treatments. A comparison of functions using BugBase indicated that the relative abundance of several functions such as biofilm formation, stress tolerance and functions related to anaerobic processes increased in the M-BF treatment. The specific growth rate, growth rate, and survival rate of shrimp were significantly higher in the P-BF system than in the CW system and the feed conversion ratio in the BFT treatments was significantly lower than that in the CW system. Overall, adding carbon sources affected water quality, microbial community, and shrimp performance. The results show that PHBV is a good alternative to carbon sources.


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