Dietary L-tryptophan requirement of fingerling stinging catfish,Heteropneustes fossilis(Bloch)

To quantify dietary L-tryptophan requirement of fingerling Heteropneustes fossilis (6.66 ± 0.08 g), casein–gelatin-based isonitrogenous (38% CP) and isoenergetic (14.72 kJ g−1 DE) purified diets with eight levels of L-tryptophan (0.12%, 0.16%, 0.20%, 0.24%, 0.28%, 0.32%, 0.36%, 0.40% dry diet) were fed to triplicate groups of fish twice daily to apparent satiation for 12 weeks. Incremental levels of dietary tryptophan from 0.12 to 0.28% significantly (P