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Ontogenic development of some digestive enzymes (proteases, amylase and lipase) in common pandora Pagellus erythrinus larva was assayed during larval development. The green‐water technique was employed for larval rearing, and whole‐body homogenates were used for enzymatic assays in triplicate. Important alterations in specific activities of all digestive enzymes measured during the period of this study were mostly related to metamorphosis and weaning. Mouth opening was observed on day 3 at 2.23±0.01 mm total length synchronously with the first determination of trypsin and chymotrypsin activities. After this date, the specific activities of these slightly increased until 25 days after hatching (DAH), respectively, and then slightly decreased and changed. The pattern determined for pepsin was strongly related to stomach formation on day 25 at 9.72±2.3 mm total length and a sharp increase was found until 30 DAH and then a slight decrease was measured from this date until the end of the experiment. Both amylase and lipase were measured for the first time on days 2 and 4, respectively, and also the specific activities of these showed similar patterns during the first week of the study. Then, slight variations were observed until 30 DAH and while lipase‐specific activity had declined, an increase in the specific activity of amylase was found until the end of the experiment. Finally, it is thought that the variations observed in the specific activity in the profile of digestive enzymes were related to either metamorphosis such as formation of stomach (25 DAH) or to changes in characteristics of food (30 DAH). The pattern of development of the main digestive enzymes found in P. erythrinus is similar to that described in other Sparid species.

The ontogenic development of the main digestive enzymes (proteases, amylase and lipase) in the red porgy, Pagrus pagrus, larvae was assayed during the larval development. The green water technique was carried out for larval rearing and whole-body homogenates were used for enzymatic assays in triplicate. Signi¢cant alterations in speci¢c activities of all digestive enzymes measured during the period of this study were mostly related to metamorphosis and weaning. Trypsin-and chymotrypsin-speci¢c activities were ¢rst detected on day 3, together with opening of the mouth, and slightly increased until 25 days after hatching (DAH). After this period, the speci¢c activities of these enzymes slightly decreased. Pepsin was ¢rst detected on day 28, concurrent with stomach formation, and a sharp increase was observed until 30 DAH. A slight decrease was measured from this date until the end of the experiment. Both amylase and lipase were measured for the ¢rst time on days 2 and 4 respectively, and the speci¢c activities of these enzymes showed similar patterns during the ¢rst week of the study. Then, slight variations were observed until 30 DAH and while lipase-speci¢c activity declined, an increase in the speci¢c activity of amylase was found until the end of the experiment. It is concluded that the variations observed in the speci¢c activity of digestive enzymes were related to either metamorphosis, such as the formation of the stomach (28 DAH), or to changes in food composition. The pro¢le of the developmental pattern of the main digestive enzymes detected in P. pagrus is similar to that described for other Sparid species.

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