SEA STARS

Some species have separate sexes and hermaphroditic species. Also generally characterized by a significant asexual reproduction, with a high power of regeneration, which can be of two types: the so-called distal schizogony, in which the body disk is divided into two halves and each tentacle regenerates and gill schizogony, in which one arm regenerates the whole animal.

There are about 1,800 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. Starfish occur across a broad depth range from the intertidal to abyssal depths (>6000 m).

reference:http://en.wikipedia.org/wiki/Starfish