Development of digestive enzymes in larvae of Solea senegalensis, Kaup 1858

The activities of some digestive enzymes were studied in sole larvae fed live prey from first feeding until the first month of life. Whole larvae body homogenates were used for enzymatic determination in larvae younger than 21 days after hatching (DAH). Older larvae were dissected in order to obtain the pancreatic and intestinal segment. Brush border membranes of enterocytes were purified from intestinal segment. From 2 DAH to 18 DAH, activities of pancreatic and intestinal enzymes exhibited a pattern characteristic of developing animals: an increase during the first 10 days post-hatching, followed by a decrease. From 21 DAH to 27 DAH, the strong increase in alkaline phosphatase activity reflected the development of the brush border membranes of enterocytes, which occurred concurrently with a decrease in a cytosolic enzyme, leucine-alanine peptidase. These opposite patterns indicate a maturation of enterocytes and the acquisition of an adult mode of digestion. (C) 1999 Elsevier Science B.V. All rights reserved.