Digestive enzymes of marine bivalves, <i>Donax cuneatus</i> and <i>Perna viridis</i>

Abstract

Amylase and protease activities were studied in the gut of D. cuneatus (as intertidal sandy-shore deposit feeder) and <i>P. viridis</i> (an intertidal rocky-shore suspension feeder). Crystalline style of both bivalves showed strong amylase activity compared to that of the digestive diverticula, indicating that the style is the main source of extracellular carbohydrate digestion in these bivalves. The digestive diverticula of both the species exhibited strong proteolytic activity. The intracellular proteolytic activity of the digestive diverticula was higher than the extracellular protein digestion exhibited by the gastric juice. The different levels of amylase and protease activity observed in these bivalves may be related to the habitats and also to the diet.