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
Spiny softshell turtle Spiny softshell turtle The spiny softshell turtle ("Apalone spinifera") is a species of softshell turtle, one of the largest freshwater turtle species in North America. Both the common name, spiny softshell, and the specific name, "spinifera" (spine-bearing), refer to the spiny, cone-like projections on the leading edge of the carapace, which are not scutes (scales). The spiny softshell turtle’s scientific name is very descriptive of the animal. “Apalone” comes from the Greek word “apalos” meaning soft or tender, and “spinifera” is of Latin descent; “spina-“ referring to thorn or spine and “-ifer” meaning bearing. This species is a member of