ISSN:
1365-2109
Quelle:
Blackwell Publishing Journal Backfiles 1879-2005
Thema:
Land- und Forstwirtschaft, Gartenbau, Fischereiwirtschaft, Hauswirtschaft
Notizen:
The effect of increasing fish loading (decreasing water exchange rate, while holding fish stocking density constant) on growth, survival and feed conversion ratio was determined for two size groups of the orange-spotted grouper Epinephelus coioides (Hamilton). Fingerlings (124.3–145.8 g initial body weight) and subadults (990.6–1147.1 g initial body weight) were reared in 1-m3 circular tanks for 14 weeks. For the fingerlings experiment, three loading rates of 0.5, 2 and 6 kg L−1 min−1 were used, while in the experiment with subadults, the loading rates were 1, 3 and 6 kg L−1 min−1. The mean growth rate of fingerlings ranged from 1.60 to 2.14 g fish−1 day−1, and survival was high (95–100%); however, there were no significant differences (P 〉 0.05) as a result of the different loading rates. Similar results were obtained in the subadults experiment, in which the growth rate (3.10–4.90 g fish−1 day−1) and survival (86.7–100%) were not significantly (P 〉 0.05) affected by the different loading rates. In both experiments, the feed conversion ratios were also not affected significantly by the loading rates. These results show that water exchange in aerated, flowthrough tanks can be reduced to as low as 6 kg L−1 min−1 without adversely affecting growth, survival and feed conversion of fingerling and subadult groupers.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1046/j.1365-2109.2000.00479.x
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