Marine life individuals per square meter and accounting for about 80% of all individual animals on earth, their diversity of life cycles, and their presence 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
Kina (animal) can be entirely eaten away, leaving bare rocks, also known as Kina Barrens. Larval stages can feed on different species of unicellular algae in a size range between 5 and 50 µm (MacEdward and Miner 2007). Molluscs such as the cymatiid gastropods "Charonia capax" and "C. rudicunda", starfish, and benthic feeding fishes can feed on individuals of "E. chloroticus" (Dix 1970a). The most important predators are the eleven-armed sea star, "Coscinasterias calamaria", the seven-armed prickly starfish, "Astrostole scabra", and the spiny lobster, "Jasus edwardsii" (Andrew and MacDiarmid 1991, Barker 2007). "Evechinus chloroticus" has an annual breeding cycle (Dix 1970b). It