Development and distribution of intestinal enzymatic activity in Paralabrax maculatofasciatus larvae fed live prey

Abstract

We describe the development and distribution of intestinal aminopeptidase M, dipeptidyl aminopeptidase IV, non-speci¢c esterase, alkaline phosphatase and acid phosphatase, using enzyme histochemistry techniques, in the spotted sand bass larvae (Paralabrax maculatofasciatus) under culture conditions. All digestive enzymes tested showed a positive reaction from ¢rst feeding (day 2) and throughout the study period (day 30). At ¢rst feeding, the main enzymatic activitywas inthemucosa throughout the intestines. Later, enzymatic activity occurred in the liver, kidney and stomach. All enzymatic activities increased from days15 to 20, remaining constant until the end of the study. This enzymatic activity suggests the onset of maturation of the digestive tract. After day 20, a positive reaction was recorded in the pyloric caeca for all tested enzymatic activities. Our studycon¢rms the digestive and absorptive functions in the intestines in spotted sand bass larvae from ¢rst feeding. It also brings new insight to establish an early weaning strategy during cultivation of spotted sand bass larvae.