Starfish Starfish Starfish or sea stars are star-shaped echinoderms belonging to the class Asteroidea. Common usage frequently finds these names being also applied to ophiuroids, which are correctly referred to as brittle stars or "basket stars". About 1,500 species of starfish occur on the seabed in all the world's oceans, from the tropics to frigid polar waters. They are found from the intertidal zone down to abyssal depths, below the surface. Starfish are marine invertebrates. They typically have a central disc and five arms, though some species have a larger number of arms. The aboral or upper surface may be smooth,
Asexual reproduction in starfish the disc begins to develop and eventually a madreporite appears. This process lasts for some time, and about 10 months after separation, the comet has a half disc and 4 arms about 1 cm (0.4 in) long. Asexual reproduction in starfish Asexual reproduction in starfish takes place by fission or through autotomy of arms. In fission, the central disc breaks into two pieces and each portion then regenerates the missing parts. In autotomy, an arm is shed which continues to live independently as a "comet", eventually growing a new disc and further arms. Only certain genera of starfish are able