The mouth of the starfish is found on the under side of the starfish creature. Food enters the mouth and into the first stomach. Then it is passed onto the secondary stomach and then into the many digestive glands that are located within each of the arms of the starfish. These digestive glands secrete enzymes and absorb the much needed nutrients from food. A small intestine runs from the secondary stomach to the external port (where the starfish disposes waste) which is located in the central upper part of the body.
Many species of starfish are able to eat their prey whole and begin digesting it before sending it to the digestive glands in the arms of the starfish. Other species are actually able to put the first stomach outside of its body (almost like it is turned inside out) where it can eat food and begin the digestion process; it then passes the food to the secondary stomach, which always stays inside.
Using its water vascular system, the starfish is able to evert its stomach into clams and mussels; forcing them open so the starfish can eat the animal inside the shell. The starfish is then able to eat these animals and start digesting without moving its position! The it can pull its stomach back inside and begin digestion! This process allows the starfish to eat animals that are much too large to fit into the starfish’s tiny mouth. Some of the animals it eats are clams, mollusks, small fish and oysters. They also eat algae to supplement their diet. Some starfish can live for weeks without eating food; it is believed that they are able to absorb nutrients from the sea water.
A great representation of starfish can be found in the lovely silver starfish necklace, which makes a great accessory to any outfit!