Requirement for tryptophan by milkfish (Chanos chanos Forsskal) juveniles
Abstract
Groups of milkfish juveniles (mean initial weight 7.7 g) were fed semipurified diets containing 0.9, 1.4, 2.1, 3.1, 4.1 and 6.1 g tryptophan/kg dry diet for 12 weeks. The mean crude protein content of the diets (containing white fishmeal, gelatin and free amino acid mixture to simulate the pattern of hydrolysed milkfish protein) was 49%. On the basis of the growth response, the tryptophan requirement of milkfish juveniles was estimated to be 3.1 g/kg diet. Fish fed low levels of tryptophan exhibited low weight gains and poor feed conversion ratios. Survival (92–100%) was consistently high in all treatments. Fish fed diets containing tryptophan levels greater than 3.1 g/kg had slightly lower survival rates. The activity of hepatic tryptophan pyrrolase showed no significant differences with increasing dietary tryptophan levels. No nutritional deficiency signs were observed other than the depression in growth rates in fish given the tryptophan deficient diets.
Citation
Coloso, R. M., Tiro, L. B., & Benitez, L. V. (1992). Requirement for tryptophan by milkfish (Chanos chanos Forsskal) juveniles.Publisher
Springer VerlagSubject
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- Journal Articles [1046]
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Article
Lactate dehydrogenase isozyme patterns during the development of milkfish, (Chanos chanos (Forskal))
-Kalikasan, The Philippine Journal of Biology , 1981 - University of the Philippines at Los BañosPolyacrylamide disc gel electrophoresis was done to determine the lactate dehydrogenase (LDH) isozyme patterns for fry (5-3 mg), fingerling (6-12 g), pond-size (150-250 g) and adult (6-9 kg) milkfish. The patterns were tissue specific; the different tissues examined, viz., eye, liver, heart, and skeletal muscle had different expressions of LDH isozymes. The resolved patterns appeared to be products of LDH gene loci A, B, and C. Subunits A and B were present in all tissues. A4 and B4 were predominant in skeletal and heart muscle, respectively; the two associated non-randomly in vivo and formed only the heteropolymers A3B and AB3. A liver band, L4, was most conspicuous in the fingerling, pond-size, and adult; it was assumed to be coded by locus C. A negatively charged band, X4, was detected in fully developed ovary and in fry homogenized as whole individuals, but it could not be resolved in tissues of fingerling. Six-mo old stunts and 3-mo old fingerlings had similar LDH patterns for all tissues examined. The patterns for 11-mo old stunts and fingerlings also were similar but the one for the eye of the former was the same pattern resolved for the eye of adults. There was no change in the LDH isozyme patterns of milk fish stunted for 6 mo under different salinity levels (0-5, 15-20, 32-35 ppt). -
Conference paper
Larviculture of marine fishes at SEAFDEC/AQD
- In CT Villegas, MT Castaños & RB Lacierda (Eds.), Proceedings of the Aquaculture Workshop for SEAFDEC/AQD Training Alumni, 8-11 September 1992, Iloilo, Philippines, 1993 - Aquaculture Department, Southeast Asian Fisheries Development CenterThe recent glut in the world market for shrimp dealt a heavy blow to the aquaculture industry. It is thus apparent that fish farmers should not depend on only a single species for culture. The popularity and market demand for grouper, sea bass, and snapper make them obvious choices as alternative culture species. On the other hand, milkfish and rabbitfish are cheaper sources of protein and they already contribute substantially to fish production from aquaculture--56.2% from milkfish for example (Rabanal 1988). However, culture and production of marine fishes are hindered by the unpredictable and seasonal seed supply. Research on larviculture at SEAFDEC/AQD are geared towards hatchery production of fry to augment supply from the wild.
