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,
Korarchaeota Korarchaeota In taxonomy, the Korarchaeota are a phylum of the Archaea. The name is derived from the Greek noun koros or kore, meaning "young man" or "young woman," and the Greek adjective archaios which means "ancient." They are also known as Xenarchaeota. Korarchaeota is regarded as a phylum, which itself is part of the archaeal TACK superphylum which encompasses Thaumarchaeota, Aigarchaeota, Crenarchaeota and Korarchaeota. Analysis of their 16S rRNA gene sequences suggests that they are a deeply branching lineage that does not belong to the main archaeal groups, Crenarchaeota and Euryarchaeota. Analysis of the genome of one korarchaeote that was