Food ration requirements of 0 super(+) yellowtail flounder Limanda ferruginea (Storer) juveniles

• Published in: Aquaculture 2003-04, Vol.220 (1-4), p.459-475
• Main Authors: Puvanendran, V, Boyce, D L, Brown, JA
• Format: Article
• Language: English
• Subjects: Limanda ferruginea; Marine
• ISSN: 0044-8486
• DOI: 10.1016/S0044-8486(02)00620-8

Several studies have shown that food ration can affect the growth of cultured fish. Determining the optimal food ration would help to achieve better growth and also provide direct economic benefits due to reduced food wastage, which would lead to commercial success. Therefore, we studied the effects of ration levels on growth performance of 0 super(+) juvenile yellowtail flounder to determine the optimal food ration. Two experiments were conducted; the first experiment as a preliminary using ration levels of 1%, 2%, 4%, 6% body weight per day (% bw day super(-1)) held at 7.0 degree C with a stocking density of 0.95 kg m super(-2) ( similar to 45% bottom coverage). Results of this preliminary experiment indicated that fish fed with 1% bw day super(-1) had significantly lower growth (weight, length, body depth and specific growth rates (SGR)) than those fed with 2%, 4% and 6% ration. However, fish fed with rations of 1% and 2% showed significantly lower gross food conversion ratios (GFCR) than fish fed with 4% and 6% rations. Survival was not significantly affected by different ration levels. Based on these preliminary results, we used ration levels of 1%, 1.5%, 2% and 3% for the main experiment. Fish were held at 10 degree C with a stocking density of 1.45 kg m super(-2) ( similar to 34% bottom coverage). Results indicated that fish fed with 1%, 1.5% and 2% bw day super(-1) had significantly lower growth than fish fed with 3% bw day super(-1). GFCR was significantly different for all four rations. It was lower for 1% than 1.5%, 2% and 3% rations. Survival was not significantly different between any treatments. We discuss our results with emphasis on growth and economics (i.e., feed wastage) and stress the need to balance both components in a commercial operation.