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Effect of light intensity on hatching rate, survival and growth in rainbow trout (Oncorhynchus mykiss) alevin
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Abasali Hajibeglou *   , Mohamad Sudagar |
| Gorgan University of Agricultural Sciences and Natural Resources |
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Abstract: (2230 Views) |
| Most fishes require a minimum threshold light intensity to be able to develop and grow. A 90-day experiment was carried out to investigate the effects of light intensity on egg hatching, survival rate and growth in rainbow trout (Oncorhynchus mykiss) alevin. Four light intensities, of 50, 200, 1000 and 2000 lux were tested in triplicates. On days 10, 20, 55 and 90, larvae were collected to assay growth parameters. The results showed that light intensity significantly affected (p˂0.05) the egg hatching, survival rate and growth of rainbow trout. The highest hatching rates were found in samples treated with the 50 lux and 200 lux light intensity, while there were no significant differences between 50 and 200 lux (p>0.05). From the eleventh day after hatching until the twentieth, the lowest percentage of abnormality was observed in 200 lux. Twenty-one to fifty-five days after hatching, optimum feed conversion ratio (FCR) and specific growth rate (SGR) were obtained in the 1000 lux treatment. At the end of the experiment, fish reared at 1000 and 2000 lux, their weight was higher than those reared at 50 lux and 200 lux (p<0.05). SGR was the highest at 2000 lux compared to other treatments (p<0.05). In conclusion light intensity fluctuation from 200 to 1000 lux could improve growth of O. mykiss which could be used as a pattern of regulation of light intensity in the commercial culture. |
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| Keywords: Light, Condition factor, Egg, Rainbow trout. |
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Full-Text [PDF 570 kb]
(621 Downloads)
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Type of Study: Research |
Subject:
Special
Received: 2017/12/5 | Accepted: 2018/06/14 | Published: 2018/09/16
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