Richard E. Strassberg earned his Ph.D. in East Asian Studies from Princeton University.
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, granular or spiny, and is covered with overlapping plates.bout 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, 6,000 m (20,000 ft) below the surface.
Starfish belong to a group or phylum of animals called echinoderms. This means spiny skinned in Greek. Echinoderms live in salt water only. They sgenerally have five arms and dwell at the bottom of oceans' levels. There are around 6000 species of echinoderms.