Starfish, which have been renamed sea stars, live in all areas of the oceans that cover the Earth. The most common form of starfish is the five-armed species that earned the species its nickname. There are versions of this marine invertebrate that have up to 40 arms.
Starfish are extremely resilient and can survive in some extreme situations. If a starfish loses part of its body, it can regrow it in time. The damage to a starfish can be quite severe, and it can still regrow parts. There only has to be a fifth of the central disk that makes up the starfish and one arm for it to be able to eventually regrow its whole body.