Ontogenetic change in digestive enzyme activity during larval development of Macrobrachium rosenbergii

Abstract

This study was conducted to determine the ontogenetic changes in trypsin, non-specific esterase and amylase activities in Macrobrachium rosenbergii during larval development. Two batches of M. rosenbergii larvae were reared separately in 300-l tanks at 50 larvae l −1. Rearing temperature and salinity were maintained at 30±2°C and 12 ppt, respectively. The larvae were daily fed with newly hatched Artemia nauplii at 5 nauplii l −1. Trypsin, esterase and amylase activities in the larvae were estimated using TAME, butyrylthiocholine iodide and corn starch, respectively, as substrates. The results showed that maximum peaks of trypsin and esterase activities occurred at stage V–VI. Amylase activity remained low until the larvae reached stage VI–VIII, indicating that the early-stage M. rosenbergii larvae are exclusively carnivorous. Maximum amylase activity was observed at stage XdashXI. In general, the ontogenetic digestive enzyme activities in developing prawn larvae seemed to coincide with hepatopancreas development.