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,
Gracile Atlantic spiny rat is inappropriate because the word has nothing to do with the meaning or etymology of the Latin "gratiosus". A rival name, "graceful spiny-rat", is no better justified; ""gratiosus"" specifically means either "enjoying favour, favoured, beloved", or "showing favour, complaisant" "a favourite", or at best "gracious", not "graceful". No authority to date has proposed a better option than using the species name, "Trinomys gratiosus" in English. Gracile Atlantic spiny rat Trinomys gratiosus is a species in the mainly South American family Echimyidae, the spiny rats; it occurs in southeast Brazil from the south bank of the River Doce, Espirito Sante, southward