The Effects Of Photoperiod On The Growth, Survival And Feeding Parameters In The Rainbow Trout (Onchorynchus Mykiss) Larvae
2007
Geramy, E. H. N., Artemia Research Institute, Urmia University. Urmia | Irani, A. J., Artemia Research Institute, Urmia University. Urmia
Light is one the important and effective environment factor in fish life. In this research, effects of photoperiod were studied on growth, survival, condition factor, specific growth rate and food conversion rate in 4 photoperiod treatments (24L/0D, 16L/8D, 16D/8L, 24D/8L) for 35 days. In this study larvae immediately after yolk sac absorption are used. The average weight of larvae was 112.28 mg at the beginning of experiment. Larvae were reared at the density 200 larvae in 40-liter tanks. The result showed that photoperiod treatments have significant effects on the weight, total length, condition factor and food conversion rate (p0.05). Whereas survival and specific growth rate in different treatments did not show significant difference. The growth rate, total length and condition factor in the 24D/0L and 16L/8D treatments were significantly lower (p0.05) than in the 24L/0D and 16D/8L treatments. Comparison of the 16L/8D and 16D/8L treatment showed that visual feeding period in trout larvae is very important. The highest growth was observed in 24L and 16D treatment. The growth rate in 24L treatment was 30% higher in compare to other treatment.
Показать больше [+] Меньше [-]