Effects of different light colors on survival and growth factors of koi carp Cyprinus carpio larvaeMehrdad Aliasghari٭, Shayan Ghobadi and Elahe Khodabakhsh

Light is an important factor in fish growth because of its effect on fish activity and metabolism. This survey was conducted to study the effects of different light colors on growth and survival of koi carp Cyprinus carpio larvae for two months. The initial weight of Koi larvae was 0.0402±0.0016g. Larvae were examined in three treatments including blue (L1), green (L2) and red (L3) light colors. Each treatment had three replicates each containing 30 koi larvae. Photoperiod was set to 14-h light and 10-h dark. Feeding was done twice a day using Biomar food. 15 fish were sampled from each tank and their body weight was measured after every other week. Survival rate was also evaluated at the end of experiment. Results showed significant differences in the growth indices between three treatments of L1, L2 and L3 (p<0.05). Blue light caused the highest growth rate followed by green and red light. No significant difference was observed in the survival rate between the treatments (p>0.05). Results showed that light color can significantly effect on koi larvae growth with the optimum growth condition by application of blue light.