The alimentary canal of Orchestia gammarella Pallas consists of the foregut, midgut and hindgut. It has been found that the ventral hepatopancreas, arising from the anterior part of the midgut, secretes the different digestive enzymes.

For the determination of optimum pH for the activity of Merent carbohydrases, Somogyi's blood sugar method has been employed and it has been investigated that the optimum pH for the activity of caecal invertase, glycogenase, amylase and amygdalinase lies between 5.6 and 6.1.