These animals at the top of the chimney are deep-sea octocorals or soft corals (Octocorallia: Alcyonacea), and sometimes go by the common name “mushroom coral.” As with other cnidarians, the mushroom coral has stinging cells or nematocysts within its flashy tentacles that are used to capture minute prey. Image courtesy of Submarine Ring of Fire 2002, NOAA/OER.
