| heal.abstract |
The growth rate of Oreochromis aureus in relation to dissolved oxygen concentrations (2.63±0.12, 3±75 ± 0.12, 6.51 ± 0.13 ppm or 31.3, 44.6 and 77.5% saturation, respectively) was investigated. Three duplicated populations of 29 specimens (mean initial body weight ∼27.3 g) were reared in 100-litre tanks for 200 days under recirculated water conditions. Fish were offered an artificial diet three times per day, 6 days per week. The obtained results showed statistically significant final body weight differences (P < 0.05) between oxygen groups and actual differences regarding their specific growth rate and food conversion ratios. However, although mean body weight increased according to the dissolved oxygen concentration, the best food conversion ratio was shown by fish of the intermediate dissolved oxygen group. It is concluded that the lowest feeding cost involved in tilapia controlled mass production, could be achieved with relatively low dissolved oxygen concentration, under simple recirculated water system conditions. © 1996 Elsevier Science B.V. |
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