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,
Ferreira's spiny tree-rat in 1817, Anselme Gaëtan Desmarest described the species based on this specimen housed in the National Museum of Natural History (France) of Paris. Using ancient DNA technology, a portion of the mitochondrial cytochrome b gene has been sequenced from a small skin fragment of this holotype. DNA sequence comparisons then suggested that the specimen was originally obtained in eastern Amazonia north of the Amazon River, most likely in the Brazilian state of Amapá. Ferreira's spiny tree-rat Ferreira's spiny tree-rat, "Mesomys hispidus", is a spiny rat species from South America. It is found in Bolivia, Brazil, Colombia, Ecuador, French Guiana, Guyana,