ASterias rubens
The starfish has a unique digestive system as it does in fact have a mouth and an anus. The mouth is located ususally on the bottom of the starfish while the anus is located on the top. This however is not the only way starfish are able to eat, they have the ability to devour a prey by pushing their stomachs outward thus allowing them to eat the prey from the exterior. If they eat the food through their mouth, it travels down the esophagus, to one of the stomachs, the cardiac stomach. After it goes through this stomach, the food goes to another stomach called the pyloric stomach. Then even after this, it goes to another part of the body, the digestive glands. This is where the actual absorbing and processing of nutrients happens. Starfish do contain a small intestine where it is connected to the stomach to take the absorbed nutrients to the external port where the waste is then excreted.
Comanthina nobilis
The Feather Star is a very unique creature. Although, it may seem as if this phylum is unable to move, they are fully capable to move, walk, crawl, roll and swim. They however, tend to cling to rocks or sponges in the water. They also use a unorthodox style of eating. They use the tentacles to grab their food. They are given the ability to grab the foods because of the sticky substance on their arms. After that, it is an easy process All they have to do is just bring the food towards the inside since, like the starfish, their stomach and anus is are located on the top of the body. From there the food is digested and broken down through the axial sinus and glands.
amphiura filiformis
The Brittle Star is also in this group of phylums because of the aquatic abilities. They also have many arms, like the feather star. They are like starfish however, they have a smaller central disk that contains all the vital organs. If by bad luck they lose a vital organ, there is no way for them to rebuild or regenerate a new one. This is different for the arms though, the arms have the ability to regenerate or create a new arm if something happens to them. One gross fact about the brittle star is that they don't have an anus. They have to get rid of their waste through their mouth. Talk about bad breath! We're not here to learn about that though, we are here to learn about the digestive system. These pictures around here are actually very hard to get a hold of. The brittle star is a nocturnal creature, only coming out at night. They like to feed on plankton. They use their rather flexible arms to grab and entangle the plankton. With the plankton in hand... or arm, they shove them to their mouth and feast!