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Tryptophan requirement of juvenile Asian sea bass Lates calcarifer
Author(s) -
Coloso R. M.,
MurilloGurrea D. P.,
Borlongan I. G.,
Catacutan M. R.
Publication year - 2004
Publication title -
journal of applied ichthyology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.392
H-Index - 62
eISSN - 1439-0426
pISSN - 0175-8659
DOI - 10.1111/j.1439-0426.2004.00478.x
Subject(s) - lates , sea bass , biology , juvenile , tryptophan , fishery , bass (fish) , zoology , meal , body weight , aquaculture , fish <actinopterygii> , food science , ecology , amino acid , biochemistry , endocrinology
Summary The dietary requirement of tryptophan for juvenile Asian sea bass ( Lates calcarifer Bloch) was studied. The juveniles (mean initial weight, 5.30 ± 0.06 g) were given semi‐purified test diets containing fish meal, gelatin, squid meal, and crystalline amino acids, for 12 weeks. Each set of isonitrogenous and isocaloric test diets contained graded levels of tryptophan. Fish (15 per tank) were reared in 250‐L fiberglass tanks provided with continuous flow‐through sea water at 26°C and salinity of 28 p.p.t. Fish were fed twice daily at a feeding rate of 8% of the body weight day −1 for the first 4 weeks and at 3.5–2.5% of the body weight day −1 from 5 to 12 weeks. The experiment was in a completely randomized design with two replicates per treatment. Mean percentage weight gains and feed efficiency ratios were significantly different in fish fed varying tryptophan levels. Survival was 100% in all treatments. On the basis of break‐point analysis of the growth response, the dietary tryptophan requirement of juvenile Asian sea bass is 0.41% of the dietary protein. This information will be useful in further refinement of practical feed formulations for the Asian sea bass.