David Hall / A Giant rock scallop (Crassadoma gigantea) encrusted with and surrounded by several other invertebrates, including White anemones (Metridium sp.), White mushroom ascidians (Distaplia sp.), Red soft co...

David Hall / Crimson anemone (Cribrinopsis fernaldi) with Candy-striped shrimps (Lebbeus grandimanus) living symbiotically. Browning Pass, Queen Charlotte Strait, British Columbia, Canada. September.

Alex Mustard / A shiver of Caribbean reef sharks (Carcharhinus perezi) swim over a coral reef with Common sea fans (Gorgonia ventalina) and sea plumes (Pseudopterogorgia sp). Jardines de la Reina, Gardens of the Que...

Alex Mustard / A vibrant Caribbean coral reef with two Reef sharks (Carcharhinus perezi) and Common sea fans (Gorgonia ventalina) and sea plumes (Pseudopterogorgia sp). Jardines de la Reina, Gardens of the Queen Nat...

Shane Gross / A Giant clam (Tridacna gigas) surrounded by Lettuce coral (Turbinaria reniformis), Kosrae, Micronesia.

Georgette Douwma / Crinoid (Crinoidea) on Soft coral (Alcyonacea). Derawan Islands, East Kalimantan, Indonesia.

Franco Banfi / Cuckoo wrasse (Labrus mixtus) male in front of Red sea fan, (Paramuricea clavata), Stupiste In dive site, Vis Island, Croatia, Adriatic Sea, Mediterranean

Shane Gross / Pink anemonefish (Amphiprion perideraion) living in symbiotic association with Magnificent sea anemone (Heteractis magnifica) Palau.

Shane Gross / Pink anemonefish (Amphiprion perideraion) living in symbiotic association with Magnificent sea anemone (Heteractis magnifica), Palau

Georgette Douwma / Translucent coral goby (Bryaninops erythrops) in Seapen (Virgularia gustaviana). Komodo National Park, Indonesia. Indo-West Pacific.

Alex Mustard / Hard corals (including Acropora sp., Platygyra sp. and Pocillopora spp.) growing in shallow water and reflected in the surface. Ras Umm Sid, Sharm El Sheikh, Sinai, Egypt. Red Sea

Alex Mustard / Western clown anemonefish (Amphiprion ocellaris) poses with a large, dominant female behind. The clownfish in the foreground is probably a juvenile. Bitung, North Sulawesi, Indonesia. Lembeh Strait, M...

Fred Olivier / Orange clownfish (Amphiprion percula) living in association with a Haddon's sea anemone (Stichodactyla haddoni), Marovo Lagoon, Solomon Islands.

Fred Olivier / Clark's anemonefish (Amphiprion clarkii) and Three spot damselfish (Dascyllus trimaculatus) swimming around anemone (Stichodactyla), Nusatupe Lagoon, Solomon Islands.

Alex Mustard / Split level image of Leather corals (Sarcophyton sp.) flourishing in shallow water close to uninhabited coral islands. Misool, Raja Ampat, West Papua, Indonesia. Ceram Sea. Tropical West Pacific Ocean...

Alex Mustard / Three Pink anemonefish (Amphiprion perideraion) living in a purple skirted magnificent sea anemone (Heteractis magnifica) on a coral reef, below a small island. Misool, Raja Ampat, West Papua, Indones...

Alex Mustard / Midnight snapper (Macolor macularis) shelters in a cavern on a coral reef with white soft corals (Scleronephthya sp.) and solderfish. Vavuu Atoll, Maldives. Indian Ocean

Alex Mustard / Pair of Western clown anemonefish (Amphiprion ocellaris) spawning orange eggs on the rock beneath their Magnificent sea anemone (Heteractis magnifica) home on a coral reef. This photo shows the larger...

Jordi Chias / Primnoella soft coral, Antarctic Peninsula, Antarctica.

Nick Hawkins / A group of frilled anemones (Metridium senile) off Bonaventure Island in the Gulf of Saint Lawrence, Quebec, Canada. September.

Pascal Kobeh / False clown anemonefish (Amphiprion ocellaris) in a magnificent sea anemone (Heteractis magnifica), Sulu sea, Philippines

SCOTLAND: The Big Picture / Orange jewel anemones (Corynactis viridis) Sula Sgeir, Scotland, UK, February.

SCOTLAND: The Big Picture / Dead man's fingers (Alcyonium digitatum) on a rocky reef with view of the sky, Shetland, Scotland, UK, August.

SCOTLAND: The Big Picture / Close up of a colony of Jewel anemones (Corynactis viridis) Scotland, UK, October.

Shane Gross / Elkhorn corals (Acropora palmata) at night silhouetted by a scientist's light during the annual coral spawn. Abaco, Bahamas.

Shane Gross / Caribbean reef shark (Carcharhinus perezi) patrolling coral reef with Schoolmaster snapper (Lutjanus apodus) and other fish. Caribbean Sea off Gardens of the Queen National Park, Cuba.

Georgette Douwma / Colonial anemones (Amphianthus nitidus) with Green urn sea squirts (Didemnum molle) (Atriolum robustum). Lembeh Strait, North Sulawesi, Indonesia.

Georgette Douwma / Corkscrew or Long tentacle anemone (Macrodactyla doreensis). Lembeh Strait, North Sulawesi, Indonesia.

Georgette Douwma / Banggai cardinalfish (Pterapogon kauderni) with a Corkscrew or Long tentacle anemone (Macrodactyla doreensis). Lembeh Strait, North Sulawesi, Indonesia.

Franco Banfi / Sugar kelp (Saccharina latissima) and Sea anemones (Actiniaria) on rock near iceberg. Tasiilaq, East Greenland. April.

Jurgen Freund / Bleached Staghorn corals (Acropora cervicornis), Great Barrier Reef, Australia, 2017.

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

David Fleetham / Clark's anemonefish (Amphiprion clarkii), pair tending to egg mass placed beside the protection of an anemone. Yap, Micronesia.

Franco Banfi / Three False clownfish (Amphiprion ocellaris) in Sea anemone (Heteractis magnifica) Lighthouse Reef, Cabilao Island, Bohol, Central Visayas, Philippines, Pacific Ocean.

Jordi Chias / Wave breaking over the reef, Table coral (Acropora) Safaga, Egypt, Red Sea.

Jordi Chias / Red Sea anemonefish (Amphiprion bicinctus) in their home, a Sea anemone (Heteractis magnifica), on a coral reef. Big Brother island, Red Sea. Egypt.

Brandon Cole / Pink anemonefish (Amphiprion perideraion) lives in symbiotic association with Magnificent sea anemone (Heteractis magnifica) Great Barrier Reef, Australia, Pacific Ocean

Alex Mustard / RF - High magnification photo of Secretary blenny (Acanthemblemaria maria) in boulder brain coral (Colpophyllia natans). East End, Grand Cayman, Cayman Islands, British West Indies. Caribbean Sea. (Th...

Alex Mustard / Hawksbill turtle (Eretmochelys imbricata) male chomps on soft coral. Jackson Reef, Sinai, Egypt. Strait of Tiran, Red Sea.

Alex Mustard / A stand of Pillar coral (Dendrogyra cylindrus) growing on a coral reef, East End, Grand Cayman, Cayman Islands

Jordi Chias / Spotted catshark (Scyliorhinus canicula) just hatched from egg case that is on Seafan (Paramuricea clavata), Ullastres seamount, Costa Brava, Llafranch, Catalunya, Spain

Alex Mustard / Boulder brain coral (Colpophyllia natans) photographed with a long exposure with camera rotation. Taken with circular fisheye lens. Grand Cayman, Cayman Islands. Caribbean Sea.

Alex Mustard / Maldive anemonefish (Amphiprion nigripes) shoal swimming in the current flowing over a Magnificent sea anemone (Heteractis magnifica). Baa Atoll, Maldives. Indian Ocean.

Alex Mustard / Western clownfish (Amphiprion oceallaris) in a Magnificent sea anemone (Heteractis magnifica). Yillet Kecil, MIsool, Raja Ampat, West Papua, Indonesia. Ceram Sea

Alex Mustard / Maldivian anemonefish (Amphiprion nigripes) shelters against a closed magnificent sea anemone (Heteractis magnifica). Male Atoll, Maldives. Indian Ocean.

Alex Mustard / RF- Western clownfish (Amphiprion oceallaris) in Magnificent sea anemone (Heteractis magnifica). Raja Ampat, West Papua, Indonesia. (This image may be licensed either as rights managed or royalty free...

Alex Mustard / Red and black anemonefish (Amphiprion melanopus) in a Bulb tentacle sea anemone (Entacmaea quadricolor). Kri Island, Raja Ampat, West Papua, Indonesia, South East Asia. Dampier Strait, Tropical West P...

Alex Mustard / Colourful reef scene with Leather corals (Sarcophyton sp.), Soft corals (Dendronephthya sp.) Seafans (Melithea sp.) and fish, including Magenta slender anthias (Luzonichthys waitei) and Scalefin anthi...