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.
Interesting Starfish Facts: Although they are named starfish, they are not related to fish at all. Starfish belong to the group of marine invertebrates which also include sea cucumber, sea urchin and sand dollar. Their star-like shape is the reason why they are named starfish or sea stars.nteresting Starfish Facts: Although they are named starfish, they are not related to fish at all. Starfish belong to the group of marine invertebrates which also include sea cucumber, sea urchin and sand dollar. Their star-like shape is the reason why they are named starfish or sea stars.