Abstract
Two 56-day trials were conducted to evaluate the effects on the performance and feed efficiency of four experimental diets formulated with different plant-based meals to completely replace fish meal for juvenile golden-lined rabbitfish (Siganus lineatus) in Palau, Micronesia. A commercial and currently employed feed was used as control, while the experimental diets were formulated and manufactured with a combination of duckweed (Lentein), fermented soybean (MrFeed Pro50s), soy protein concentrate (Profine), and soybean meal. 120 Fish (trial 1: 9.29 ± 0.14 g/fish; trial 2: 7.74 ± 0.25 g/fish) per trial were stocked in groups of 10 in floating cages (47.7L) within two 3-ton flow-through tanks. Control and experimental diets were fed to quadruplet cages by hand to visual satiation for one hour four times a day to a maximum of 5% body weight in trial 1, and two times per day to a maximum of 3% body weight in trial 2. Trial 1 tested diet 1 (42% Lentein, 15% MrPro50s) and diet 2 (42% Lentein, 15% soybean meal) with no significant differences (p ≥ .05) in terms of growth performances (final weight, weight gain and specific growth rate) and feed utilization (feed conversion ratio and protein efficiency ratio), while feed intake was significantly different (p ≤ .05). Trial 2 tested diet 3 (23% soy protein concentrate, 20% soybean meal) and diet 4 (27% soy protein concentrate, 10% soybean meal) with significant differences in terms of growth performances but no differences in terms of feed utilization and feed intake. Survival was unaffected by the treatments (p ≥ .05).