One afternoon, Oscar was hungry... "mmm..." Oscar said,"Maybe I can get a crab. He has nothing against my radula and beak." So he rips the crab up into his beak and chows down.

(webquest)

His friend Chad the Clam was also very hungry. "I can't do what you did, Oscar. But i sure can get this algae floating around right now with my Gills!"

(Webquest)

Many of Oscar's friends that are like him that have their body between two shells are herbivores, they mainly feed on algae. Squids and octopuses, like Oscar, are predators and feed on fish and other sea creatures. The mollusk snails are mixed with herbivores and carnivores.

(Note Chart)

Clams like Chad (and all mollusks) have a complete digestive system. ... Digestion is extracellular. This means that digestive enzymes break food down into food particles and food molecules within the hollow intestine. Food molecules diffuse or are actively transported into the cells lining the intestine.

(Note Chart)

Within squids, like Oscar, the digestive tract includes a mouth where they insert their food, a radula that helps break the food into smaller pieces , a stomach where the enzymes that break down the food are, a digestive gland that secretes digestive enzymes and excretes metabolic waste, and the anus where any extras are exerted.

Snails' digestive tracts are a little more complicated and consist of the mouth, radula, mouth, digestive gland and anus which all have the same jobs as in the squid. However snails also have a crop which helps store food before the actual digestion, and an intestine which helps resorb water from from food and delivers the excess food to the anus.