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,
Echinoderma rounded cells, and a brownish cap and stipe, with brown scales. The name comes from the Greek "echinos" (ἐχῖνος) meaning a hedgehog or sea-urchin and "derma" (δέρμα) meaning skin, referring to the spiny cap surface. The noun "derma" is neuter and therefore if the species name is an adjective, it needs to take the neuter ending (example: "Echinoderma asperum"). Echinoderma Echinoderma is a genus of fungi in the family Agaricaceae. Its members were for a long time considered to belong to genus "Lepiota" and the group was then circumscribed by French mycologist Marcel Bon in 1981 as a subgenus of