The names "starfish" and "sea star" essentially refer to members of the Class Asteroidea. However, common usage frequently finds "starfish" and "sea star", which are correctly referred to as "brittle stars" or "basket stars".
There are 2,000 living species of starfish that occur in all the world's oceans, including the Atlantic, Pacific, Indian as well as in the Arctic and the Southern Ocean (i.e., Antarctic) regions.
TEN FACTS ABOUT STAR FISH
1. Sea stars are not fish.
2. Sea stars are related to sand dollars, sea urchins, and sea cucumbers.
3. There are thousands of sea star species.
4. Not all sea stars have 5 arms.
5. Sea stars can regenerate a lost arm.
6. Sea stars are protected by armor.
7. Sea stars do not have blood.
8. Sea stars move on their tube feet.
9. Sea stars eat with their stomach inside-out.
10. Sea stars have eyes.