Juergen Freund / Timelapse of a Scolymia coral (Mussidae) feeding, lit with a UV light, Cairns, North Queensland, Australia.

Juergen Freund / Timelapse of a Scolymia coral (Mussidae) feeding, lit with a UV light, Cairns, North Queensland, Australia.

Linda Pitkin / Coral (Cynarina lacrymalis), on wreck of the SS Thistlegorm Sha'ab Ali, Gulf of Suez, Egypt, Red Sea.

Alex Mustard / Hard coral (Lobophyllia hemprichii) close up, Bitung, North Sulawesi, Indonesia. Lembeh Strait, Molucca Sea.

Pascal Kobeh / Hard coral (Lobophyllia) half dead with fishes swimming around, Madagascar. Indian Ocean.

Pete Oxford / Reef showing diversity of coral, Fiji

Franco Banfi / Close up detail of hard coral, unidentified species, Maldives, Indian Ocean

Georgette Douwma / Hard coral (Lobophyllia hattai) and sponge, Rinca, Komodo National Park, Indonesia

Fred Bavendam / Stony Coral (Lobophyllia sp) colony showing bleaching in all but one of its large polyps, Lembeh Strait, Indonesia

Chris Newbert / Stony Coral (Lobophyllia sp) colony, Solomon Islands

Gary Bell/ Oceanwide / Stony Coral (Lobophyllia hemprichii), Great Barrier Reef, Australia

Pete Oxford / Coral (Mussidae), Raja Ampat Islands, Indonesia

Roberto Rinaldi / Coral (Mussidae) fluorescence at night, captured using very powerful electronic strobes, Red Sea

Roberto Rinaldi / Polyps of a hard coral, Philippines.

Roberto Rinaldi / Bigeye cardinalfish (Apogon bandanensis) sheltering in branches of a hard coral, Sulawesi, Indonesia.

Roberto Rinaldi / Close up of hard coral polyps, Philippines.

Roberto Rinaldi / Coral (Mussidae) fluorescence at night, captured using very powerful electronic strobes, Red Sea

Tony Wu / Colony of Lobed cactus coral (Lobophyllia hemprichii) spawning by releasing both eggs and sperm at same time. East China Sea, Kagoshima Prefecture, Japan.

Alex Mustard / Fluorescent coral (Lobophyllia hemprichii) at night on a coral reef in blue light. Laamu Atoll, Maldives, Indian Ocean.

Alex Mustard / Coral fluorescence (Lobophyllia sp.) at night, under blue light, on a coral reef, Laamu Atoll, Maldives, Indian Ocean.

Alex Mustard / Coral fluorescence (Symphyllia sp.) at night, under blue light, on a coral reef, Laamu Atoll, Maldives, Indian Ocean.

Jacob Guy / Scoly coral (Scolymia) feeding under UV light, Corwall, UK. Filmed in studio.

Magnus Lundgren / Close up of Brain coral (Merulinidae or Mussidae) with its feeding tentacles extended, Triton Bay, West Papua, Indonesia, Pacific Ocean.

Magnus Lundgren / Brain coral (Merulinidae or Mussidae) close up, Triton Bay, West Papua, Indonesia, Pacific Ocean.

Magnus Lundgren / Brain coral (Merulinidae or Mussidae) close up, Raja Ampat, West Papua, Indonesia, Pacific Ocean.

Pascal Kobeh / Reef with in the foreground hard corals (Lobophyllia sp., perhaps Lobophyllia robusta) and a soft coral. Indonesia, Sea of Flores.

Claudio Contreras / Disk Coral (Scolymia sp.), Cienaga de Zapata National Park, Matanzas Province, Cuba.

Claudio Contreras / Disk Coral (Scolymia sp.), Cienaga de Zapata National Park, Matanzas Province, Cuba.