What is the habitat of the starfish and what does it eat

Starfish, or more accurately sea stars, fill a niche as predator and prey in marine ecosystems close to shore. With more than 18,000 species in the world, they range from the tropics to the Pacific Northwest and further north. They can grow larger than a foot across and can have as many as 40 arms. While sea stars are known for their ability to regrow lost arms, they have an unusual digestive system, too.