David Fleetham / Fire Dartfish / Fire Goby (Nemateleotris magnifica) against colourful coral. Fiji's outer reef.

Alex Mustard / Group of predators hunting together, in an example of 'Nuclear foraging'. The Moray eel (Gymnothorax javanicus) flushes out prey, and is followed by a Napolean wrasse (Cheilinus undulatus) and a Bluef...

Juergen Freund / Chambered nautilus (Nautilus pompilius) with red whip coral. Osprey Reef, Great Barrier Reef, Queensland, Australia.

Richard Robinson / Featherstar (Crinoidea) on red coral (Errina novazelandiae) in Doubtful Sound, Fiordland National Park, New Zealand.

Juergen Freund / Fluorescent corals (Favia sp) Great Barrier Reef, Australia

Georgette Douwma / Yellowbar angelfish (Pomacanthus maculosus) swimming over coral reef with soft corals. Egypt, Red Sea.

Alex Mustard / Caribbean spiny lobster (Panulirus argus) scampers across a coral reef amongst sponges, Bloody Bay Wall, Little Cayman, Cayman Islands. British West Indies, Caribbean Sea.

Juergen Freund / Gorgonian fan coral with Featherstar / crinoid attached, West New Britain, Papua New Guinea.

Juergen Freund / Hook and line fishermen in dugout canoe and self made goggles catching a coral grouper for growing on in cage for the Live reef fish trade, Wakatobi, South Sulawesi, Indonesia

Juergen Freund / Soft coral (Alcyonacea) in the shallow mangroves with diver, split level. North Raja Ampat, West Papua, Indonesia, February 2010

Juergen Freund / Denise's pygmy seahorse (Hippocampus denise) in its fan coral. Misool, Raja Ampat, West Papua, Indonesia

Jeff Rotman / Klunzinger's wrasse (Thalassoma rueppellii / klunzingeri) swimming past diver, Sinai Peninsula, Red Sea, Egypt. Model released. Model released.

Alex Mustard / Caribbean reef shark (Carcharhinus perezi) swims over a coral reef. Grand Bahama Island, Bahamas. Tropical West Atlantic Ocean.

Georgette Douwma / Tree coral (Dendronephthya sp) on sandy sea bed. Rinca, Komodo National Park, Indonesia

Jeff Rotman / Close-up of the eye of a Jewel Grouper / Coral hind (Cephalopholis Miniata) Red Sea, Egypt

Jeff Rotman / Jewel Grouper / Coral hind (Cephalopholis Miniata) with mouth open, Red Sea, Egypt

Georgette Douwma / Coral reef scenery with Gorgonian and shoal of Pygmy / Glassy sweepers (Parapriacanthus guentheri) Egypt, Red Sea

Georgette Douwma / Red Sea bannerfish (Heniochus intermedius) pair at rest near firecoral and soft corals. Red Sea, Egypt.

Georgette Douwma / Emperor angelfish (Pomacanthus imperator). Red Sea, Egypt.

Georgette Douwma / Big-eye or Goggle-eye (Priacanthus hamrur) on wreck. Note colour change from deep red to silver. Egypt, Red Sea

Georgette Douwma / Seafan {Gorgonacea} Great Barrier Reef, Australia

Georgette Douwma / Seafan {Gorgonacea} Great Barrier Reef, Australia

Doug Perrine / Red whip coral {Ellisella sp} Bahamas

Michael & Patricia Fogden / Clark's Coral Snake (Micrurus clarki) venomous snake with warning coloration, rainforest, Costa Rica

Georgette Douwma / Red coral with polyps extended {Corallium rubrum} Balearic Is, Mediterranean

Juergen Freund / Tube coral (Dendrophyllia) Philippines, Pacific Ocean

Sue Daly / Red sea fingers coral {Alcyonium glomeratum} Sark, Channel Is, UK

Georgette Douwma / Coral reef landscape. Shallow reef with Anthias and wave. Red Sea, Egypt, North-Africa

Brent Hedges / Hawksbill turtle eating soft coral, Red Sea

Georgette Douwma / Longnose hawkfish on coral, Red Sea.

Jeff Rotman / Prickly Alcyonarian coral {Dendronepthya sp} close-up, Red Sea

Juergen Freund / Lionfish on coral reef, Indo-Pacific

Shane Gross / Coral reef wall with sponges, Caribbean reef shark (Carcharhinus perezi) in background. Caribbean Sea off Gardens of the Queen National Park, Cuba.

Shane Gross / Common ghost goby (Pleurosicya mossambica) on soft coral, Alor, Indonesia.

David Fleetham / Painted frogfish (Antennarius pictus) with first dorsal spine and lure extended to attract prey. Dumaguete, Philippines.

David Fleetham / Imperial commensal shrimp (Periclimenes imperator / Zenopontonia rex) on Spanish dancer nudibranch (Hexabranchus sanguineus) at night. Philippines.

David Fleetham / Flagtai / V-taill grouper (Cephalopholis urodeta) in coral reef. Yap, Micronesia.

Georgette Douwma / Gorgonian sea fan (Melithaea sp.) with Lyretail anthias (Pseudanthias sqamipinnis). Similan Islands, Andaman Sea, Thailand

Georgette Douwma / Kaleidoscopic image of Coral reef scenery with gorgonian, soft corals and Lyretail anthias (Pseudanthias squamipinnis). Rinca, Komodo National Park, Indonesia.

Linda Pitkin / Coral reef with Anthias fish (Pseudanthias squamipinnis) and Twotone chromis (Chromis dimidiata) around Yellow scroll coral (Lettuce coral) (Turbinaria reniformis). With diver Jackson Reef, Straits...

Linda Pitkin / Coral reef with Anthias fish (Pseudanthias squamipinnis) and Twotone chromis (Chromis dimidiata) around Yellow scroll coral (Lettuce coral) (Turbinaria reniformis) Jackson Reef, Straits of Tiran, R...

Linda Pitkin / Stony coral (Porites sp.) with Anthias (Pseudanthias squamipinnis) Ras Ghozlani, Ras Mohammed National Park, Egypt, Red Sea.

Linda Pitkin / Stony coral (Porites sp.) with Anthias (Pseudanthias squamipinnis), and diver Ras Ghozlani, Ras Mohammed National Park, Egypt, Red Sea.

Franco Banfi / Red sea whip coral (Ellisella sp) Lighthouse Reef, Cabilao Island, Bohol, Central Visayas, Philippines, Pacific Ocean.

Franco Banfi / Longnose hawkfish (Oxycirrhites typus) two in coral, Tubbataha Reef Natural Park, UNESCO World Heritage Site, Sulu Sea, Cagayancillo, Palawan, Philippines

Franco Banfi / Longnose hawkfish (Oxycirrhites typus) Tubbataha Reef Natural Park, UNESCO World Heritage Site, Sulu Sea, Cagayancillo, Palawan, Philippines

Franco Banfi / Longnose hawkfish (Oxycirrhites typus) in coral, Tubbataha Reef Natural Park, UNESCO World Heritage Site, Sulu Sea, Cagayancillo, Palawan, Philippines

Franco Banfi / Longnose hawkfish (Oxycirrhites typus) hiding in coral, Tubbataha Reef Natural Park, UNESCO World Heritage Site, Sulu Sea, Cagayancillo, Palawan, Philippines

Franco Banfi / Coral hawkfish (Cirrhitichthys oxycephalus), Sea of Cortez, Baja California peninsula, Mexico, East Pacific Ocean.

Franco Banfi / Soft coral (Dendronephthya), Aldabra Atoll, Natural World Heritage Site, Seychelles, Indian Ocean.

Franco Banfi / Soft coral (Dendronephthya), Aldabra Atoll, Natural World Heritage Site, Seychelles, Indian Ocean.

Sue Daly / Close-up of a colony of Red sea fingers (Alcyonium glomeratum), showing polyps, Sark, British Channel Islands, UK, August.

Sue Daly / Colony of Red sea fingers (Alcyonium glomeratum), Sark, British Channel Islands, UK, August.

Sue Daly / Wide angle shot with open and closed colonies of Red sea fingers (Alcyonium glomeratum), Sark, British Channel Islands, UK, August.

Georgette Douwma / Gorgonian / Sea whip coral (Ellisella ceratophyta), close up, West Papua, Indonesia.

Linda Pitkin / Sea whips, gorgonian coral (Ellisella sp.) Cape Kri, Dampier Strait, Raja Ampat, West Papua, Indonesia, March 2016

Alex Mustard / Dome coral (Porites nodifera) pinnacle or bommie surrounded by fish, including Scalefin anthias (Pseudanthias squamipinnis), with diver Fury Shoal, Egypt. Red Sea.

Georgette Douwma / Gorgonian sea fan (Melithaea sp.) with Lyretail anthias (Pseudanthias sqamipinnis) Similan Islands, Andaman Sea, Thailand.

Franco Banfi / Red gorgonian coral (Paramuricea clavata) covered with mucilage, a symptom of rising sea temperature, Punta Campanella Marine Reserve, Massa Lubrense, Italy, Tyrrhenian Sea, Mediterranean.

Franco Banfi / Red fan corals (Paramuricea clavata), Yellow gorgonian, (Eunicella cavolini) and Yellow cave-sponges (Aplysina cavernicola), Ischia Island, Italy, Tyrrhenian Sea, Mediterranean.

Juergen Freund / Harlequin ghost pipefish (Solenostomus paradoxus) amongst Red sea whips (Ellisella sp) Kimbe Bay, New Britain, Papua New Guinea.

Richard Robinson / Dorid nudibranch (Aphelodoris luctuosa) on a red coral (Errina novazelandiae) in Doubtful Sound, Fiordland National Park, New Zealand..

Richard Robinson / Starfish (Henricia sp) on a red coral (Errina novazelandiae) in Doubtful Sound, Fiordland National Park, New Zealand..

Richard Robinson / Red coral (Errina novazelandiae) in Doubtful Sound, Fiordland National Park, New Zealand..

Richard Robinson / Red coral (Errina novazelandiae) in Doubtful Sound, Fiordland National Park, New Zealand.

Richard Robinson / Red coral (Errina novazelandiae) in Doubtful Sound, Fiordland National Park, New Zealand.

Richard Robinson / Red coral (Errina novazelandiae) in Doubtful Sound, Fiordland National Park, New Zealand.

Richard Robinson / Red coral (Errina novazelandiae) in Doubtful Sound, Fiordland National Park, New Zealand.

Richard Robinson / Red coral (Errina novazelandiae) in Doubtful Sound, Fiordland National Park, New Zealand.

Richard Robinson / Red coral (Errina novazelandiae) in Dusky Sound, Fiordland National Park, New Zealand.

Richard Robinson / Red coral (Errina novazelandiae) in Dusky Sound, Fiordland National Park, New Zealand.

Pascal Kobeh / Coral reef with hard corals (Acropora ) and Jewel fairy basslets / anthias (Pseudanthias squamipinnis) and Yellow-tail / yellowback basslets (Pseudanthias evansi) Maldives. Indian Ocean.

Pascal Kobeh / Coral drop off with soft corals (Dendronephthya) and (Sarcophyton ), hard corals (Acropora) and (Porites) and Jewel fairy basslets (Pseudanthias squamipinnis) Sudan. Red Sea.

Pascal Kobeh / Coral drop off with hard corals possibly (Porites) and Kewel fairy basslets (Pseudanthias squamipinnis) Sudan. Red Sea.

Pascal Kobeh / Coral drop off with hard corals (Porites) and jewel fairy basslets (Pseudanthias squamipinnis) and two-band anemonefish (Amphiprion bicinctus) in a Mertens' sea anemone (Stichodactyla mertensii) Sudan...

Pascal Kobeh / Pair of Masked butterflyfish (Chaetodon semilarvatus), pair of Red Sea bannerfish (Heniochus intermedius) and Blackspotted sweetlips (Plectorhinchus gaterinus) under a hard coral table (Acropora) Suda...

Pascal Kobeh / Pair of Masked butterflyfish (Chaetodon semilarvatus), pair of Red Sea bannerfish (Heniochus intermedius) and Backspotted sweetlips (Plectorhinchus gaterinus) under a hard coral table (Acropora) Sudan...

Alex Mustard / Golden damselfish (Amblyglyphidodon aureus) hiding amongst the branches of red whip coral (Ctenocella sp.) Misool, Raja Ampat, West Papua, Indonesia.

Solvin Zankl / Whip coral (Ellisella ceratophyta) on reef, Raja Ampat, West Papua, Indonesia, Pacific Ocean.

Solvin Zankl / Whip coral (Ellisella ceratophyta) on reef, Raja Ampat, West Papua, Indonesia, Pacific Ocean.

Franco Banfi / Necklaces made from Mediterranean Red coral (Corallium rubrum), Vulnerable (IUCN), Village of Komisa, Vis Island, Croatia, Adriatic Sea, Mediterranean

Franco Banfi / Necklace made from Mediterranean red coral (Corallium rubrum) Vulnerable (IUCN), Village of Komisa, Vis Island, Croatia, Adriatic Sea, Mediterranean

Franco Banfi / Gorgonian sea fan (Acalycigorgia sp.) Raja Ampat, Irian Jaya, West Papua, Indonesia, Pacific Ocean

Juergen Freund / Fluorescent corals (Scolymia australis) Great Barrier Reef, Australia

Sue Daly / Polyps of Red Fingers Soft Coral (Alcyonium glomeratus). Pavlaison, Sark, British Channel Islands, July.

Sue Daly / Polyps of Red Fingers Soft Coral (Alcyonium glomeratus). Pavlaison, Sark, British Channel Islands, July.

Sue Daly / Red Fingers Soft Coral (Alcyonium glomeratus). Vingt Clos, Sark, British Channel Islands, August.

Sue Daly / Red Fingers Soft Coral (Alcyonium glomeratus). Vingt Clos, Sark, British Channel Islands, August.

Sue Daly / Red Fingers Soft Coral (Alcyonium glomeratus) Vingt Clos, Sark, British Channel Islands, August.

Sue Daly / Red Fingers Soft Coral (Alcyonium glomeratus) Vingt Clos, Sark, British Channel Islands, August.

Sue Daly / British underwater scenic with Red Fingers Soft Coral (Alcyonium glomeratus) L'Etac, Sark, British Channel Islands, August.

Linda Pitkin / 2020VISION / Red sea fingers (Alcyonium glomeratum), Lundy Island Marine Conservation Zone, Devon, England, UK, May.

Linda Pitkin / 2020VISION / Red sea fingers (Alcyonium glomeratum), Lundy Island Marine Conservation Zone, Devon, England, UK, May.

Linda Pitkin / 2020VISION / Red sea fingers (Alcyonium glomeratum), Lundy Island Marine Conservation Zone, Devon, England, UK, May.