The Digestive System of The Common Starfish (Asterias rubens)
The mouth of the Common Starfish is located in the center of its underside. Its anus is located on its top side. The starfish uses its mouth to pull food into its body. It has two stomachs: the cardiac stomach and the pyloric stomach. In some situations the cardiac stomach can be pushed out of the starfish’s body where it engulfs prey and begins digestion. In addition, in some cases, the starfish will force open a bivalve, such as a clam, and push its stomach into the shell, digesting it in its shell. The cardiac stomach is then brought back inside the body where the partially digested food is passed into the pyloric stomach. If the cardiac stomach is not pushed outside the starfish, the food simply passes from the mouth to stomach where it is partially digested, then to the pyloric stomach. The food is further digested in the intestine and waste is excreted through the anus.
The mouth of the Common Starfish is located in the center of its underside. Its anus is located on its top side. The starfish uses its mouth to pull food into its body. It has two stomachs: the cardiac stomach and the pyloric stomach. In some situations the cardiac stomach can be pushed out of the starfish’s body where it engulfs prey and begins digestion. In addition, in some cases, the starfish will force open a bivalve, such as a clam, and push its stomach into the shell, digesting it in its shell. The cardiac stomach is then brought back inside the body where the partially digested food is passed into the pyloric stomach. If the cardiac stomach is not pushed outside the starfish, the food simply passes from the mouth to stomach where it is partially digested, then to the pyloric stomach. The food is further digested in the intestine and waste is excreted through the anus.