Triplefin hiding amongst corals. Triplefin (family Tripterygiidae) fish sheltering in a small Tubastrea Sp. coral colony (dark) surrounded by Xenia sp. corals (light). Tubastrea are hard corals that have very large polyps and form large, branching colonies in current-swept areas. Xenia are a type of soft coral. They are unique because of their ability to use their branching 'arms' to push water away from the colony in a constant, grabbing motion. Photographed off Komodo National Park, Komodo, Indonesia.