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.
