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.

Mark MacEwen / Firefly squid (Watasenia scintillans) close to beach during mating season. Toyama Bay, Japan.

Solvin Zankl / Deepsea Octopus (Bathypolypus bairdii) specimen from the North Atlantic, near the Faroe Islands at a depth of 805m

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

Barry Bland / Fried egg jelly fish (Cotylorhiza tuberculata) Mediterranean Sea.

Solvin Zankl / Black backed jackal (Canis mesomelas) attacking Cape fur seal (Arctocephalus pusillus) pup, Sperrgebiet National Park, Namibia, December. Sequence 3/6

Franco Banfi / Mass stranding of Humboldt squid (Dosidicus gigas) on shore of Baja California, Mexico, East Pacific Ocean. These mass strandings are thought to be caused by 'red tides' or build ups of toxic algae.

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

Nick Upton / Jenny Lewis watching rescued Grey seal pups (Halichoerus grypus) peering from a trailer on a beach on release day, after recovering from their injuries through treatment and rehabilitation at the Corn...