Sci/230 week 7 physiology Assignment
January 5, 2013
University of Phoenix
Starfish are very unique creatures. Starfish are sometimes called sea stars. They are classified as invertebrate Echinoderm. Starfish are commonly found in rocky tide pools and are sometimes found washed up onto shore of all the world oceans. They live in tropical waters and on the seafloors of colder climate. Starfish does not have blood. They have a water vascular system where the starfish pumps sea water through it sieve plate or madreporite into its tube to extend them.
The ability to regenerate torn limbs and lost body is the most fascinating adaptation to its dangerous environment underwater. If a predator attacks a starfish it can regrow almost their entire bodies. This adaptation is possible because most or all their vital organs and nervous system are located inside of their arm. Starfish does not have a brain.
Starfish has also evolved to fit their environment by developing feeding habits. Most starfish are carnivorous they prey on animals such as oysters, mussels, sea snails, and also clams. They find their prey with light sensing eyespots. These eyespots are located at the end of each of their arm. One is also located in the center of their bodies. It can only sense light and dark. They pry open the oysters with suction-cupped feet by wrapping their around the oyster shell and then pushes it stomach through its mouth and into the open shell. A starfish have two stomachs. They are call the cardiac stomach which is a sac-like organ located at the center of their bodies and then it the pyloric stomach where the digestion is completed. This adaptation allows starfish to eat animals larger than their mouth. Starfish are protected by their leathery or slightly prickly skin. Starfish have a tough covering on their upper side which is made up of calcium carbonate with tiny spins on their surface. It used to protect them from predators. They...
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