Depending on the species, starfish grow to be a variety of different sizes, colors and shapes, but all look like a star. The giant sea star is the widest starfish, reaching 3 feet in diameter. The Patririella parvivipara is the smallest starfish, growing to less than half an inch.
There are 2,000 species of starfish found in the ocean. They are marine animals and do not live in freshwater. Starfish are able to regenerate limbs. All of their vital organs are located in their arms. Starfish are able to consume prey outside of their bodies. Their stomach emerges from their mouth and moves inside clams and oysters that the starfish's arms have pried open. The stomach then envelops the prey and moves back inside the starfish.