Heydarnejad M.S.,Shahrekord University |
Parto M.,Esfahan Payam Noor University |
Pilevarian A.A.,Esfahan Payam Noor University
Journal of Animal Physiology and Animal Nutrition | Year: 2013
The influence of light colours on growth and stress response in rainbow trout Oncorhyncus mykiss (15.16±0.29cm; 32.27±1.18g) was studied. Fish were reared in 16 glass aquaria (140×30×80cm) each with 12 fish under one of four different lighting spectra: yellow (546nm), red (605nm), blue (470nm) and white (full spectrum, control). Experiments lasted 125days. The stress response was evaluated by measuring cortisol levels. Body weight and total length of the fish reared under yellow light were greater compared with the other colour regimes while feed conversion ratio significantly lowers. Condition factor and specific growth rate, however, were not differentiated among experimental light treatments. Stressed fish showed lower cortisol levels under yellow light compared with other light exposures. The study indicates that under laboratory conditions, rainbow trout grow best under yellow light and that yellow light lowers the stress-induced cortisol response in this fish species. © 2011 Blackwell Verlag GmbH.