Nick Hawkins / Galapagos green turtle (Chelonia mydas agassizi) swimming above sea floor with shoal of fish in background. Off San Cristobal Island, Galapagos.
Jurgen Freund / Timelapse of Giant sea cucumbers (Thelenota ananas) moving underwater, with a Giant clam (Tridacna gigas) in the background, Great Barrier Reef, Queensland, Australia, 2015.
David Fleetham / Day / Big blue octopus (Octopus cyanea) with diver in background. Hawaii. September 2012.
David Fleetham / Whitetip reef shark (Triaenodon obesus) resting on sea floor. Kauai, Hawaii.
David Fleetham / Clark's anemonefish (Amphiprion clarkii), pair tending to egg mass placed beside the protection of an anemone. Yap, Micronesia.
Alex Mustard / Tawny nurse shark (Nebrius ferrugineus) group, individuals circling each other at dusk. Vavuu Atoll, Maldives. Indian Ocean.
Alex Mustard / Hawksbill turtle (Eretmochelys imbricata) pair circling each other above coral reef. Seven Mile Beach, Grand Cayman, Cayman Islands, British West Indies. Caribbean Sea.
Alex Mustard / RF - Southern stingray (Dasyatis americana) swimming over sand in shallow water at dawn, Cayman Islands, Caribbean Sea. (This image may be licensed either as rights managed or royalty free.)
Alex Mustard / RF - Pod of Atlantic spotted dolphins (Stenella frontalis) swimming over a shallow, sandy seabed. North Bihmini, Bahamas. (This image may be licensed either as rights managed or royalty free.)
Alex Mustard / Grey seal (Halichoerus grypus) young female opens her mouth and blows bubbles through her nose playfully while she looks up from the seabed. Lundy Island, Devon, UK, Bristol Channel. August. Highly co...
Claudio Contreras / American crocodile (Crocodylus acutus) resting just above seagrass underwater, Banco Chinchorro Biosphere Reserve, Caribbean region, Mexico
Tony Wu / Juvenile Australian sea lion (Neophoca cinerea) resting in shallows, possibly to thermoregulate, Carnac Island, Western Australia.