Growth Rate, Proximate Composition and Fatty Acid Profile of Juvenile kutum Rutilus frisii kutum Under Light/Dark Cycles

This study investigated the growth rate, proximate composition, and fatty acid profile in juvenile of kutum Rutilus frisii kutum in different dark-light cycles. Fish were stocked randomly in eighteen 2000-L fiberglass tanks and received six photoperiod regimes: natural photoperiod, 24L (light):0D (day), 16L:8D, 12L:12D, 8L:16D and 0L:24D. Application of continuous dark (0L:24D) and an intermediate photoperiod (12L:12D) resulted in the highest specific growth rate (SGR) as well as lowest feed conversion ratio (FCR) (P < 0.05) in kutum. The quantity of crude protein and ash of kutum subjected in continuous dark (0L:24D), exhibited higher rate than other photoperiod regimes. The proportion of DHA (docosahexaenoic acid) +EPA (eicosapentaenoic acid) content ranged from 3.20% in natural photoperiod to 3.52% in continuous dark, n-3/n-6 and PUFA/SFA fatty acids ratio slightly ranged from 0.15-0.18, and 0.99-1.08 in all photoperiod regimes, respectively. © 2011 Jordan Journal of Biological Sciences. All rights reserved