Alex Mustard / Lion's mane jellyfish (Cyanea capillata) with feeding tentacles spread swimming in the sun in shallow water. Gulen, Norway. North East Atlantic Ocean.

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

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 / Aggregation of Golden jellyfish (Mastigias sp.) in a marine lake in Palau, the golden colour of this species comes from symbiotic algae in its tissues. Jellyfish Lake, Eil Malk island, Rock Islands, P...

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

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

Luis Quinta / Moon jellyfish (Aurelia aurita) near the surface, Santa Maria Island, Azores, September.

Pascal Kobeh / 'Lotus', an artificial reef built in 2001 with a steel frame with a mild electrical current which encourages the growth of coral, Ihuru Island, North Male Atoll, Maldives, Indian Ocean. Small reprodu...

Michael Pitts / Anemones (Actiniaria) with Maldives anemonefish (Amphiprion nigripes) and Surgeonfish (Acanthurus) moving in a strong current, Maldives, Indian Ocean.

Alex Mustard,Alex Mustard / Green surf anemones (Anthopleura xanthogrammica) grow in shallow water below the temperate rain forest. Browning Pass, Port Hardy, Vancouver Island, British Columbia, Canada. North East Pacific Ocean.

Claudio Contreras,Claudio Contreras / Dynamite blasted reef, near Taglibas, Danajon Bank, Central Visayas, Philippines, April 2013

Juergen Freund / Flexible Leather Coral (Sinularia flexibilis) spawning during the annual mass coral spawning event, in November, Great Barrier Reef, Queensland, Australia