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,
Spiny dogfish and 11 but average 6 or 7. Spiny dogfish are bottom-dwellers. They are commonly found at depths of around , but have been found deeper than . Life span is estimated to be up to 100 years and their gestation period is 18 to 24 months, which may be the longest of any known animal. Spiny dogfish are consumed as human food in Europe, the United States, Canada, New Zealand and Chile. The meat is primarily consumed in England, France, the Benelux countries and Germany. The fins and tails are processed into fin needles and are used in less expensive