IMPACTS OF ILLUMINATION TIME AND COLOR ON TILAPIA OUTGROWTH AND FISH FLESH QUALITY

Abstract

The present study was aimed to look at the impacts of illumination time and illumination color on outgrowth and activity of Nil Tilapia (Tilapia Niloticus). A commercial food was used for feeding fish during experimental period. The data obtained from the experiment were subjected to one-way analysis of variance (ANOVA) (using SPSS program). The results indicated that illumination time (24, 16 hour and control) and illumination colors (white, red and blue) were significantly affected on fish activity. The fish outgrowth at illumination blue was higher than other illumination colors for all illumination time. The illumination blue and long illumination time (24 light hours) created the top fish percentage weight gained during feeding period (WGDFP = 52.9 g), specific growth rate (SGR = 4.08 %), daily growth rate (DGR = 17.63 %) and growth efficiency (GE = 29 %). On the other side, the blue illumination and short illumination time 16 h created weight gained during feeding period (WGDFP = 46.5 g), specific growth rate (SGR = 3.89 %), daily growth rate (DGR = 15.51 %) and growth efficiency (GE = 28 %). At long illumination time, the feed conversation efficiency (FCE) was 92, 95 and 98 % at illumination white, red and blue respectively. There were significant differences in crude protein and crude fat contents among fish exposed to different photoperiod regimes. Fish exposed to (24 h) illumination regime had significantly lower crude fat and ash than those of the other.