Norbert Wu / Orange Tube Coral (Tubastraea aurea) polyps extended only at night, Dutch Antilles, Caribbean

Fred Bavendam / Fusilier (Caesio sp) school streaming over a vast field of Disc Coral (Turbinaria reniformis), Manado, Sulawesi, Indonesia

Alex Mustard / Yellow cabbage coral (Turbinaria reniformis) growing on a coral reef, surrounded by scalefin anthias: Pseudanthias squamipinnis. Ras Mohammed National Park, Sinai, Egypt. Red Sea

Alex Mustard / Large green branching coral (Tubastrea sp.) with damselfish on a coral reef. Misool, Raja Ampat, West Papua, Indonesia. Misool Marine Protected Area. Ceram Sea. Tropical West Pacific Ocean.

Gary Bell/ Oceanwide / Disc Coral (Turbinaria reniformis) and Banana Fusilier (Pterocaesio pisang) school, Great Barrier Reef, Australia

Pascal Kobeh / Scleractinia / Orange hard coral (Dendrophyllia ramea) with a diver in the background, Canary Islands

Magnus Lundgren / Wild Wonders of China / Yellow tube coral (Tubastrea faulkneri) with the polyps open, Ninepin Group or Kwo Chau Islands, Hong Kong, China.

Magnus Lundgren / Wild Wonders of China / Sun / Tube coral (Tubastraea sp) with tentacles extended to catch zooplankton. Gulf of Bohai, Yellow Sea. Penglai / Dengzhou / Tengchow, Yantai, Shandong Province, China.

Magnus Lundgren / Wild Wonders of China / Sun / Tube coral (Tubastraea sp) with tentacles extended to catch zooplankton. Gulf of Bohai, Yellow Sea. Penglai / Dengzhou / Tengchow, Yantai, Shandong Province, China.

Linda Pitkin / Orange cup coral (Tubastraea sp.), and soft corals, Triton Bay, near Kaimana, West Papua, Indonesia

Linda Pitkin / Orange cup corals (Tubastraea sp.), Triton Bay, near Kaimana, West Papua, Indonesia

David Fleetham / Colony of Green tube coral (Tubastraea micranthus) feeding at night, Fiji Islands.