A unique ecosystem lives on the upper flank of Ruby volcano, consisting largely of numerous small brown/red crabs and small limpets that colonize the small rocks and sand within the iron-oxide zone. The inset shows zoomed-in view of one of the crabs, which were hard to distinguish from the surrounding red rocks and sediment. The red circles outline some of the crabs in the image. Image courtesy of Submarine Ring of Fire 2006 Exploration, NOAA Vents Program
