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 orb-weaver the smaller male lacks the spiny projections and instead has four to five stubby dark projections. Orb-weavers' bites are generally harmless to humans. , the World Spider Catalog accepted the following species: Spiny orb-weaver Spiny orb-weavers is a common name for Gasteracantha, a genus of spiders. They are also commonly called spiny-backed orb-weavers, due to the prominent spines on their abdomen (compare genus "Isoxya"). These spiders can reach sizes of up to in diameter (measured from spike to spike). Although their abdomen is shaped like a crab shell with spikes, it is not to be confused with a crab spider.