Manee Srichanun, Chutima Tantikitti, Vichai Vatanakul, and Poramet Musikarune

pp. 247 - 254

Abstract

Mystus nemurus is one of the economically important freshwater species fish for aquaculture in Thailand. The aim of
this study was to describe the development of proteolytic enzymes (pepsin, trypsin and chymotrypsin), carbohydrase (α-
amylase) and lipase, and the influence of live feed during early stage of larval development. Enzymatic assays were conducted
from day 1 to day 45 after hatching in larvae fed the following feed sequence: Moina sp. during 3-15 day after hatching
(DAH), co-feeding between Moina sp. and powder feed during 16-29 DAH and artificial diet during 30-45 DAH. Three
samples of larvae were collected before morning feeding on days 1, 3, 5, 7, 9, 12, 15, 20, 25, 30, 35, 40 and 45. All enzymes
were detected at low level as early as hatching and remained constant until 20 DAH. Significant increases of pepsin, trypsin,
chymotrypsin and α-amylase activity were detected during 25-45 DAH (p<0.05) whereas lipase activity showed an increase
during 30-45 DAH, which was related to an increased growth of fish larvae at 30 DAH onward (p<0.05). Live feed, Moina sp.,
significantly increased enzyme activity of trypsin, chymotrypsin and -amylase of fish larvae during 3-15 DAH in comparison with those of unfed fish larvae (p<0.05).