Abstract. This study aims to find growth rate and protein content of humpback grouper, Cromileptes altivelis, through the utilization of hardmilk wood plant, Alstonia acuminata, and other local materials as artificial feed composition. This experiment used 12-13 cm long-humpback grouper, C. altivelis. They were reared in the aquarium filled with 100 liters of seawater at a density of 6 individuals per aquarium. There were 4 experimental feed types with addition of different concentration of A. acuminata plant, 0.1% (A), 0.2% (B), 0.3% (C), 0.4% (D), and control treatment (without A. acuminate addition). Protein content of each treatment wa the same, 45%. The study applied a Complete Randomized Design with 3 replications. Results revealed that treatment B gave the highest mean growth rate with mean daily weight increment of 4 g and daily length increment of 0.011 cm, and mean absolute weight increment of 73 g and absolute length increment of 4.594 cm. As conclusion, feeding C. altivelis with addition of 0.2% A. acuminata can raise the growth rate with high survival rate.
Key Words: local material, Alstonia acuminata, aquarium culture, experiment.