The spotted seatrout, Cynoscion nebulosus, has significant potential for aquaculture in the Gulf of Mexico. In fish aquaculture, the availability of high-quality fingerlings is the most critical factor for its commercial success . However, the current state of spotted seatrout culture technology is limited to reproductive and larval rearing protocols (to reduce cannibalism). In order to identify physiological biomarkers of the digestive system to optimize feeding strategies (diet design and weaning) during larval development of spotted seatrout. T he objective of this study was to assess the activity of digestive key enzymes (pepsin, alkaline protease, trypsin, chymotrypsin, leucine aminopeptidase , alkaline phosphatase, amylase, and bile salt-dependent lipas e) in this specie from hatching until day 30. Multivariate analysis identified three digestive stages. The first stage occurred between 1 and 3 days after hatching (DAH); a period of digestive stability showed the highest activity in amylase and bile salt‐dependent lipase. The second stage was a period of digestive transition (from 4 to 20 DAH), during which leucine aminopeptidase, chymotrypsin, and alkaline proteases were identified as the predominant enzymes from 4 to 5 DAH. In the third stage , a period of digestive stability , pepsin was the major enzyme that occurred between 25 and 30 DAH. These results indicate that the spotted seatrout larvae have a digestive system adapted to lipids and carbohydrates at the onset of feeding with an immediate transition to protein digestion when exogenous feeding begins.
*corresponding author: mggc@ciencias.unam.mx