Franco Banfi / Schooling Scalloped hammerhead sharks (Sphyrna lewini) Cocos Island National Park, Costa Rica.

Juergen Freund / Mud crab (Scylla serrata) in shallow sandy water. Split level with island and thatched house on stilts. Moromahu Island, Wakatobi, South Sulawesi, Indonesia. Second Place in the Portfolio Award of the...

Juergen Freund / Whale shark (Rhincodon typus) split level view, Cenderawasih Bay, West Papua, Indonesia. Second Place in the Portfolio Award of the Terre Sauvage Nature Images Awards Competition 2015.

Alex Mustard / Portrait of a Severn's pygmy seahorse (Hippocampus severnsi) at Mioskon Island, Raja Ampat, West Papua, Indonesia. Dampier Strait. Tropical West Pacific Ocean.

Alex Mustard / Portrait of Bigfin squid (Sepioteuthis lessoniana) hovering in open water above a coral reef at night. Dampier Strait, Raja Ampat, West Papua, Indonesia. Tropical West Pacific Ocean

Alex Mustard / Black hamlet (Hypoplectrus nigricans) and Yellowbelly hamlet (Hypoplectrus aberrans) spawning at dusk. As this genus is quite recently evolved hybridization is still possible. Hamlets are one of the...

Alex Mustard / Harlequin sweetlips (Plectorhinchus chaetodonoides) cleaned by a pair of bluestreak cleaner wrasse (Labroides dimidiatus). South Atoll, Tubbataha Atolls, Tubbataha Reefs Natural Park, Palawan, Philipp...

Alex Mustard / Reef octopus (Octopus cyanea) portrait near wreck. Gubal Island, Egypt. Red Sea.

Solvin Zankl / Portuguese man-of-war (Physalia physalis) colony, underwater Sargasso Sea, Bermuda

Chris & Monique Fallows / Long-beaked common dolphin (Delphinus capensis) porpoising in still water, False Bay, South Africa

Chris & Monique Fallows / Long-beaked common dolphin (Delphinus capensis) school near the water?s surface, False Bay, South Africa

Mike Read / Commerson's dolphin (Cephalorhynchus commersonii) pod, surfing the waves, Saunders Island, Falkland Islands, November.