Effect of dietary L-tryptophan on cannibalism, growth and survival of Asian seabass, Lates calcarifer (Bloch, 1790) fry

Abstract

The effect of L-tryptophan (TRP) supplemented diets at levels of 0, 0.5, 1.0, 1.5 and 2% on cannibalism, survival and growth performance of Asian seabass, Lates calcarifer (Bloch, 1790) fry was evaluated. Thirty days old seabass fry (mean weight: 0.31±0.16 g) were reared for 45 days in a recirculating aquaculture system. Results of the present experiment showed that L-tryptophan (TRP) supplementation from 0.5 to 2% in diet significantly (p<0.05) reduced cannibalism compared to control diet and did not affect growth performance. The lowest survival percentage (14%) was noticed in control group, whereas a higher survival percentage (33.33 to 39.80) was observed in TRP supplemented groups. Coefficient of size variation (%) ranged from 21.50 to 91.61 and decreased with increased level of TRP supplementation, Similar results were also obtained in size heterogeneity. Based on the results of the study, it is recommended to supplement 0.5% of TRP in larval diet to reduce cannibalism and improve survival of seabass fry.