1Brackishwater Aquaculture Research Centre, Gelang Patah, Johore, Malaysia.
2National Prawn Fry Production and Research Centre, Kg. Pulau Sayak, Kedah, Malaysia.

Soya bean meal has been used with varying degrees of success as a replacement for fish meal in diets for many species. In terms of protein level, Mohammed Suhaimee et al. (1999) reported that soya bean meal protein can substitute up to 51% fish meal protein; with an inclusion level of 40 % soya bean meal (40%-SBM) in juvenile seabass Lates calcarifer diet without significantly affecting growth rate compared to fish fed diets containing 0% soya bean meal.
However, the effect of minerals, in high soya bean meal diet on seabass L. calcarifer are not fully understood. This is due to the fact that phosphorus is the most critical mineral in soybean meal. Unlike calcium, phosphorus is not absorbed in significant quantity from the water by fish (Lovell, 1978). Thus, fish diets containing a high percentage of soya bean meal with low percentage of fish meal or animal by-products would be deficient in phosphorus.
Consequently, an experiment was carried out to evaluate the effect of mineral content especially phosphorus in high soya bean meal diet for its potential to partially substitute fish meal in seabass L. calcarifer feed.
An 8-week feeding trial was conducted to evaluate the effect of not incorporating commercial BIOFOS® (Ca:P, 21:11) in high soya bean meal diet typically the 40%-SBM on the growth of seabass L. calcarifer juveniles. The effect of mineral content in the 40%-SBM diet on seabass was examined using the diets detailed in Table I.
There were 3 formulated diets used. Two diets were formulated such that the inclusion of soya bean meal levels was at 40% and one diet was at 0% for control (Diet 3). Diet 1 was the 40%-SBM diet without additional commercial BIOFOS® and Diet 2 was the 40%-SBM incorporated with 2.6% BIOFOS® as the 40%-SBM diet in Mohammed Suhaimee et al. (1999). All the diets were kept isonitrogenous and isolipid at around 45 % protein and 13 % lipid respectively. The trial was conducted in triplicate using 9 front-glass fibreglass aquarium tanks with 150-L working capacity each. Each aquarium tank was fully aerated and having flow-through brackishwater supply system. Seabass juveniles with 17.94 ± 0.38g (mean ± standard deviation) body weight were randomly stocked in the aquarium tanks at a stocking density of 8 pieces/tank.
Proximate composition and amino acid profile of the diets examined in this experiment is shown in Table II. Chemical analyses confirmed that the protein and fat contents of the diets were very similar. The health of the fish remained excellent throughout the experiment and no losses occurred. The productivity responses of the fish are detailed in Table III.