Characterization of protease activity in developing discus Symphysodon aequifasciata larva

摘要

The activity of different protease classes was monitored in developing discus (Symphysodon spp.) larvae using a combination of biochemical assays and substrate SDS-PAGE techniques. Results showed the presence of alkaline proteases of serine proteases such as trypsin with a significant increase in activity levels detected beginning 3 days after hatching. Other alkaline proteases such as metallo-proteases and chymotrypsin, a type of serine protease, were only detected in older larval stages, at around 20-30 days after hatching. Acidic protease activity was very low during the first 20-25 days of development before showing a significant (P < 0.01) rise. This is despite the formation of a stomach observed 10 days after hatching. Based on the development of the protein digestive system observed, the use of microdiets to replace Artemia should be considered 25 days after hatching.