Starfish or sea stars are star-shaped echinoderms. 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, 6,000m below the surface.br/br/These marine invertebrates are opportunistic feeders and are mostly predators on benthic invertebrates. They have complex life cycles and can reproduce both sexually and asexually. Most can regenerate damaged parts or lost arms and they can shed arms as a means of defence.