Changes of Digestive Enzymatic Activity on Yellowtail Snapper (Ocyurus chrysurus) During Initial Ontogeny

Yellowtail snapper ( Ocyurus chrysurus ) is one of the most important Lutjanids species in the Caribbean due to its great importance in recreational and commercial fishing activities. Studies related to digestive physiology are essential to improve survival after hatching as high mortalities have been reported during larviculture. The aim of this study was to determine the changes in the activities of alkaline and acid proteases, trypsin, chymotrypsin, leucine aminopeptidase, lipase, amylase and alkaline phosphatase in O. chrysurus during their initial ontogeny through biochemical techniques. Larvae were fed with live prey ( Nannochloropsis sp and Brachionus rotundiformis ) from the opening mouth until 10 days after hatching (DAH), subsequently fed with rotifers and Artemia sp . nauplii until 15 DAH and finally were feed with enriched lipid emulsion Artemia sp . metanauplii to 42 DAH. Activities of most alkaline digestive enzymes started 5 DAH expressing differentially according to larval growth and larvae live diet. Furthermore, the activity of pepsin in O. chrysurus peaked at 34 DAH, suggesting the presence of a functional stomach. It is concluded that the early activity of most alkaline enzymes reflects the contribution of pancreatic and cytosolic enzymes, and that the weaning period could start after 34 DAH after the observed peak of levels.