P 23 The Effect of different dietary lipid levels on the growth performance of Angel fish (Pterophyllum alturn) in indoor aquarium conditions

Abstract

Effect of dietary lipid level on growth performance of Angel fish (Pterophyllum altum) was experimented in 24 week study. Three isonitrogenous (42% Protein) diets with varying lipid levels of 12% (LI2), 16% (LI6) and 20% (L20) were used. The test feeds ingredients were fish meal, Soybean meal, Punnak, Shrimp meal, Wheat flour, and Soybean oil with, vitamin & mineral mixture. Larvae of P. altum (21 days old) were placed in glass tanks (60 x 3 Ox 30 cm) at a ratio of 6 larvae/tank. Fish were fed adlibitum and measured frequency was maintained at 3 times per day to calculate the food conversion ratio. Growth performance of fish (Total length, standard length and weight) was measured at four week intervals and %SGR and % survival was calculated. Water temperature was monitored daily and Ammonia levels were measured once in two weeks. The Final mean total body weights of fish were 5.87 ±2.57a, 7.15+ 0.86b and 7.22+1.41b g for LI2, LI6 and L20 diets respectively and fish fed on L16 and L 20 diets had significantly higher body weights at the end of the experimental period . Total lengths-of fish were 6.21+1.0, 6.66+0.34, 6.78+0.38 cm for L12, L16 and L20 diets respectively. Feed conversion ratio was 2.19, 1.88 and 1.92 for L12, L16 and L20 diets respectively. The survival rates were 100% for all treatments. Fish fed on diets with higher dietary lipid (L 16: 2.19+0.01 and L20: 2.23+0.01) showed significantly higher % SGR compared to the fish fed on diets with low dietary lipid (L12: 2.10±0.03), treatments. Mean water temperature was 23.1+1.2 C° and Ammonia level was 0.19+0.04 mg/L. When comparing the three dietary lipids, fish fed on LI6 and L20 diets were significantly larger (higher body weights & %SGR) compared to the fish fed on diets with L12.