Apple Snail- Ampullariidae
When the food is eaten it mixes with digestive enzymes and slime with the muscular movements of the gizzard. The surface of the gizzard had many parallel folds (ridges) and the walls consist of several muscular layers. The ducts of the digestive gland or midgut gland, which produces digestive enzymes, opens in the ciliated vestibule. The midgut gland lies on top of the stomach and in line with the testis or ovarias in the upper area of the shell. The function of the midgut gland might be compared with the human liver (biochemical conversions of nutrients and waste) combined with the pancreas (production of digestive enzymes), and is also called the hepatopancreas. One can recognize the midgut gland easily due to it's dark brown color. The apple snail normally eats algae.
This is a picture of the apple snail.