Abstract. This study aims to examine artificial feed formula application with addition of Alstonia acuminata plant on humpback grouper Cromileptes altivelis parents. It was carried out in Kelanit waters, Southeast Maluccas. The experimental fish were C. altivelis parents with body weight of 1027-1455 g. They were kept in 12 floating fish cages of 1 x 1 x 2 m at a density of 10 ind plot-1 with 3 replications. The artificial feed was enriched with A. acuminata of 0.1 g (treatment A), 0.2 g (treatment B), 0.3 g (treatment C), and 0.4 g (treatment D) in 100 g feed. Feeding was done twice a day, between 06.00 and 07.00 a.m. and between 17.00 and 18.00 p.m. as much as 5% of fish biomass. Protein content of the feed was 45%. The study employed group randomized design for a 30 day-observation. Results showed significantly different effect of A. acuminata plant addition to daily growth rate, and feed consumption. The highest specific growth rate, weight increment, daily feed consumption, and feed efficiency and the lowest feed conversion ratio were recorded in treatment D, addition of 0.4 g A. acuminata.

Key Words: feed, growth, feed consumption, feed conversion ratio