scholarly journals Effects of stocking density on growth and feed utilization of grouper (Epinephelus coioides) reared in recirculation and flow-through water system

2014 ◽  
Vol 9 (9) ◽  
pp. 812-822 ◽  
Author(s):  
Putra A. Samad Agus ◽  
Fan Hua Nan ◽  
Meng Chou Lee
2015 ◽  
Vol 75 (4 suppl 1) ◽  
pp. 97-107 ◽  
Author(s):  
E. G. P. Favaro ◽  
L. H. Sipaúba-Tavares ◽  
A. Milstein

Abstract In Southeastern Brazil tilapia culture is conducted in extensive and semi-intensive flow-through earthen ponds, being water availability and flow management different in the rainy and dry seasons. In this region lettuce wastes are a potential cheap input for tilapia culture. This study examined the ecological processes developing during the rainy and dry seasons in three extensive flow-through earthen tilapia ponds fertilized with lettuce wastes. Water quality, plankton and sediment parameters were sampled monthly during a year. Factor analysis was used to identify the ecological processes occurring within the ponds and to construct a conceptual graphic model of the pond ecosystem functioning during the rainy and dry seasons. Processes related to nitrogen cycling presented differences between both seasons while processes related to phosphorus cycling did not. Ecological differences among ponds were due to effects of wind protection by surrounding vegetation, organic loading entering, tilapia density and its grazing pressure on zooplankton. Differences in tilapia growth among ponds were related to stocking density and ecological process affecting tilapia food availability and intraspecific competition. Lettuce wastes addition into the ponds did not produce negative effects, thus this practice may be considered a disposal option and a low-cost input source for tilapia, at least at the amounts applied in this study.


2012 ◽  
Vol 3 ◽  
pp. 13-17 ◽  
Author(s):  
Devi Lal Adhikari ◽  
Chikashi Sato ◽  
Shobha Kanta Lamichhane

Photolysis and sonolysis of trichloroethylene (TCE) in water was investigated using a cup-horn, flow-through reactor system. Water containing titanium dioxide was deliberately contaminated with TCE. These solutions were irradiated with ultraviolet light (UV) and ultrasonic waves (US). The decrease in the TCE concentration was observed in water under both US and UV treatments. Present findings declare that the use of UV and US decreased the TCE concentration. With the reactor specifications used, the photolysis and sonolysis processes can produce water meeting the drinking water standard (MCLs of 5?g/L) for TCE.The Himalayan PhysicsVol. 3, No. 32012Page : 13-17


2016 ◽  
Vol 48 (4) ◽  
pp. 611-622 ◽  
Author(s):  
Mohammad Yooneszadeh Feshalami ◽  
Farokh Amiri ◽  
Mansour Nikpey ◽  
Seyed Abdolsaheb Mortazavizadeh ◽  
Enric Gisbert ◽  
...  

2020 ◽  
Vol 27 (2) ◽  
pp. 154
Author(s):  
Vivi Endar Herawati ◽  
Pinandoyo Pinandoyo ◽  
Seto Windarto ◽  
Putut Hariyadi ◽  
Johannes Hutabarat ◽  
...  

High protein content in maggot is one of the advantages for increasing fish growth through artificial feed. This study aimed to find the best optimization and feed formulation for fish meal substitution with maggot meal on growth, feed utilization efficiency, and survival rate of milkfish (C. chanos). Milkfish (C. chanos) with an average weight of 0.62±0.01 gram/fish was used as test fish. Feeding is carried out at 07.00 a.m., 12.00 p.m., and 17:00 p.m. through fixed feeding rate method. The tested fish was kept for 42 days with a stocking density of 1 fish/l. The experimental design used was a completely randomized design with five treatments and three replications. The treatments which had been done were fish meal substitution with maggot meal as follows: A (0%), B (25%), C (50%), D (75%), and E (100%). The research parameters included total feed consumption (TFC), feed utilization efficiency (FUE), protein efficiency ratio (PER), relative growth rate (RGR), survival rate (SR), and water quality. The results showed that the fish meal substitution with maggot meal had a significant effect (p<0.05) on FUE, PER, RGR and had no significant effect (p>0.05) on TFC and SR. The best treatment of each treatment is in treatment C with a composition of 50% maggot meal substitution on fish meal which resulted in a TFC value of 40.17±4.58, FUE of 27.51±0.77, PER of 0.83±0.03%, and RGR of 2.34±0.10.


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