Amino acid composition of developing larval freshwater prawn Macrobrachiumrosenbergii

Amino acid profiles of freshwater prawn Macrobrachium rosenbergii were dete rmined during early larval stages (I-IX) to provide some baseline biochemic al information of the growing larvae. The larvae obtained from several fema les were stocked into three 250-L tanks at a density of 30 larvae/L. The fe eding regime consisted of newly hatched Artemia nauplii and egg custard con taining 5% cod liver oil. For each developmental stage, larval samples from each experimental tank were pooled, freeze dried and after acid hydrolysis , the quantification of amino acids was done by a reverse phase high perfor mance liquid chromatography (N = 2). The highest represented of the total a mino acids were for glutamic acid and phenylalanine (with cystine) with ran ges from 13.4-16.6 and 9.7-11.5%, respectively, whereas tryptophan (1.4-1.6 %), methionine (1.4-2.7%) and histidine (2.9-4.2%) were relatively lower. T he levels of the following essential amino acids did not significantly chan ge during larval development: arginine, leucine, phenylalanine (plus cystin e), threonine, tryptophan and valine. Despite statistically significant cha nges that were observed in levels of some amino acids, amino acid compositi on appeared to be relatively unchanged during the larval growth. The result s may suggest that the amino acid requirements of the freshwater prawn is r elatively constant during larval life and can be satisfied by a suitable pr otein source that resembles the larval amino acid profile.