Marine invertebrates at various trophic levels point at an important role in many ecosystems. Echinoderms (Greek for "spiny skin") is a phylum which contains only marine invertebrates. The adults are recognizable by their radial symmetry (usually five-point) and include starfish, sea urchins, sand dollars, and sea cucumbers, as well as the sea lilies. Echinoderms are found at every ocean depth, from the intertidal zone to the abyssal zone. The phylum contains about 7000 living species, making it the second-largest grouping of deuterostomes (a superphylum), after the chordates (which include the vertebrates, such as birds, fishes, mammals, and reptiles). Echinoderms are unique among
Starfish to mid 20th century, this species was common along the coasts of the West Indies, but collection and trade have severely reduced its numbers. In the State of Florida, "O. reticulatus" is listed as endangered and its collection is illegal. Nevertheless, it is still sold throughout its range and beyond. A similar phenomenon exists in the Indo-Pacific for species such as "Protoreaster nodosus". With its multiple arms, the starfish provides a popular metaphor for computer networks, companies and software tools. It is also the name of a seabed imaging system and company. Starfish has repeatedly been chosen as a name