Mark Carwardine / Great white shark (Carcharodon carcharias) underwater, Guadalupe Island, Mexico (North Pacific)

Alex Mustard / Orange painted frogfish (Antennarius pictus) fishing. Here the frogfish is illuminated by a snooted strobe and the background sand lit with a red LED torch. Bitung, North Sulawesi, Indonesia. Lembeh S...

Alex Mustard / Free swimming mimic octopus (Thaumoctopus mimicus). Bitung, North Sulawesi, Indonesia. Lembeh Strait, Molucca Sea.

Alex Mustard / Free swimming mimic octopus (Thaumoctopus mimicus). Bitung, North Sulawesi, Indonesia. Lembeh Strait, Molucca Sea.

Alex Mustard / Thorny seahorse (Hippocampus histrix) gripping onto a sponge. Bitung, North Sulawesi, Indonesia. Lembeh Strait, Molucca Sea.

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...

Alex Mustard / Two female Common seahorses (Hippocampus kuda) fighting over territory on the seabed. The brief fight was preceeded by a ritualised, synchronised parade. Bitung, North Sulawesi, Indonesia. Lembeh Stra...

Alex Mustard / Common seahorse (Hippocampus kuda) female wrapping her prehensile tail around piece of wood on the seabed. Bitung, North Sulawesi, Indonesia. Lembeh Strait, Molucca Sea.

Alex Mustard / Veined octopus (Amphioctopus marginatus) shelters inside an old clam shell, with silver-sides in the water above. Bitung, North Sulawesi, Indonesia. Lembeh Strait, Molucca Sea.

Alex Mustard / Whitemargin stargazer (Uranoscopus sulphureus) sets an ambush in the sand at night. Bitung, North Sulawesi, Indonesia. Lembeh Strait, Molucca Sea.

Alex Mustard / Veined octopus (Amphioctopus marginatus) emerging from its home in an old clam shell. Bitung, North Sulawesi, Indonesia. Lembeh Strait, Molucca Sea.

Alex Mustard / Reef lizardifsh (Synodus variegatus) at a cleaning station, being cleaned by Holthuis anemone shrimps (Ancylomenes holthuisi). Bitung, North Sulawesi, Indonesia. Lembeh Strait, Molucca Sea.

Alex Mustard / Shoal of three Bigfin reef squid (Sepioteuthis lessoniana) in open water at night. Bitung, North Sulawesi, Indonesia. Lembeh Strait, Molucca Sea.

Alex Mustard / Portrait of a Giant frogfish (Antennarius commersoni) on a large Yellow elephant ear sponge (Ianthella basta). Bitung, North Sulawesi, Indonesia. Lembeh Strait, Molucca Sea.

Georgette Douwma / Shortfin lionfish (Dendrochirus brachypterus). Lembeh Strait, North Sulawesi, Indonesia.

Georgette Douwma / Nudibranch (Chromodoris willani) with a scale worm. Lembeh Strait, North Sulawesi, Indonesia.

Georgette Douwma / Ribbon eel ( Rhinomuraena quaesita) Lembeh Strait, North Sulawesi, Indonesia.

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.

Georgette Douwma / Thornback cowfish (Lactoria fornasini). Lembeh Strait, North Sulawesi, Indonesia.

Georgette Douwma / Boxer Crab (Lybia tessellata) with sea anemones in its claws for defense. Lembeh Strait, North Sulawesi, Indonesia.

Georgette Douwma / Taylor's pygmy leatherjacket (Brachaluteres taylori). Lembeh Strait, North Sulawesi, Indonesia.

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

David Fleetham / Humpback Whale (Megaptera novaeangliae) beginning a deep dive. Hawaii.

David Fleetham / Close up of the pattern on the Hawaiian spotted flatworm (Pseudobiceros) endemic to Hawaii.

David Fleetham / Blue-spotted Sea Urchin (Astropyga radiata) expelling waste from the sac in the center of it's body. Maui, Hawaii.

David Fleetham / Jaws and teeth of Stout Moray (Gymnothorax eurostus). Hawaii.

David Fleetham / Day / Common Reef Octopus (Octopus cyanea) swimming. Hawaii.

David Fleetham / Silhouette of a Green Sea Turtle (Chelonia mydas) passes overhead. West Maui, Hawaii.

David Fleetham / Green Sea Turtles (Chelonia mydas) gathering at a cleaning station off where small fish will remove their parasites. West Maui, Hawaii.

David Fleetham / Green Sea Turtle (Chelonia mydas) below surf instructor Tara Angioletti on a stand-up paddle board off Canoe Bearch, Maui, Hawaii. Model released.

David Fleetham / Patterns of diffused sunlight on Humpback whale (Megaptera novaeangliae), Hawaii.

David Fleetham / Curious Humpback whale calf (Megaptera novaeangliae) during moment away from its mother, Hawaii.

David Fleetham / Schooling Lemon / Milletseed butterflyfish (Chaetodon miliaris) below kayakers off Maui, Hawaii.

David Fleetham / Schooling Lemon butterflyfish (Chaetodon miliaris) near to surface. Maui, Hawaii.

David Fleetham / Looking upwards to schooling Lemon butterflyfish (Chaetodon miliaris) near to surface. Maui, Hawaii.

David Fleetham / Schooling Raccoon butterflyfish (Chaetodon lunula) framed in a lava formation off the island of Lanai, Hawaii.

David Fleetham / Schooling Raccoon butterflyfish (Chaetodon lunula) framed in a lava formation off the island of Lanai, Hawaii.

David Fleetham / White mouthed moray eel (Gymnothorax meleagris), Hawaii.

David Fleetham / Pair of Yellow edged moray eels (Gymnothorax flavimarginatus) in coral crevice, Hawaii.

David Fleetham / Sargasum frogfish (Histiro histiro) near the surface floating on discarded polypropylene rope, Hawaii.

David Fleetham / Common reef octopus (Octopus cyanea), Hawaii.

David Fleetham / Hawaiian pom-pom / boxer crab (Lybia edmondsoni)with anemones (Triactis sp) that it carries around holding with the claws and using them for defense, waving in front of the possible aggressor. An exam...

David Fleetham / Green turtle (Chelonia mydas) swimming towards surface, Hawaii.

David Fleetham / Guineafowl pufferfish (Arothron meleagris) puffed up in defence, Hawaii.

Jeff Rotman / Head and gills of juvenile Scalloped hammerhead shark (Sphyrna Lewini), Kane'ohe Bay, Hawaii, Pacific Ocean.

Alex Mustard / Veined octopus (Amphioctopus marginatus) sheltering in an old clam shell, with plankton swirling around it at night (captured as trails in the long exposure). Bitung, North Sulawesi, Indonesia. Lembeh...

Alex Mustard / Nudibranchs (Doto greenamyeri) newly described species on feather hydroids. Seraya Bay, north coast of Bali, Indonesia. Java Sea.

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...

Georgette Douwma / Blue triggerfish (Pseudobalistes fuscus). Egypt, Red Sea. Indo-Pacific.

Alex Mustard / Red eye medusa (Polyorchis penicillatus) with hitchhiking amphipods (Hyperia medusarum). Browning Pass, Vancouver Island, British Columbia, Canada. North East Pacific Ocean.

Alex Mustard / Great white shark (Carcharodon carcharias) portrait, Guadalupe Island, Mexico. Pacific Ocean.

Constantinos Petrinos / Yellow stripe clingfish (Diademichthys lineatus) living in association with the Fire Urchin (Astropyga radiata) Lembeh Strait, North Sulawesi, Indonesia.

Constantinos Petrinos / Purple short tentacle mushroom coral (Fungia sp.) close up of polyps. Lembeh Strait, North Sulawesi, Indonesia.

Constantinos Petrinos / Bigfin reef squid (Sepioteuthis lessoniana) schooling parallel to one another. Lembeh Strait, North Sulawesi, Indonesia.

Constantinos Petrinos / Chromodorid nudibranch (Chromodoris annae) on Sea Squirt (Polycarpa aurata) Lembeh Strait, North Sulawesi, Indonesia.

Constantinos Petrinos / Peacock-tail anemone shrimp (Periclimenes brevicarpalis) living commensally with the Branching Sea Anemone (Actinodendron glomeratum). Lembeh Strait, North Sulawesi, Indonesia.

Alex Mustard / Reticulate stargazer (Uranoscopus sp.) emerging from the sand. Bitung, North Sulawesi, Indonesia. Lembeh Strait, Molucca Sea.

Alex Mustard / Emperor shrimp (Periclimenes imperator / Zenopontonia rex) hitchhiking on large t-bar nudibranch (Ceratosoma trilobatum) The shrimp gains food source and protection on the toxic seaslug. Bitung, North...

Alex Mustard / Close up of tiny (10mm) Pygmy seahorse (Hippocampus bargibanti) living disguised in Muricella sp. sea fan. Bitung, North Sulawesi, Indonesia. Lembeh Strait, Molucca Sea.

Doug Perrine / Scuba diver films bait ball of Bigeye scad (Selar crumenopthalmus) Keauhou Bay, Kona, Hawaii, Hawaiian Islands. Central Pacific ocean. March 2010. Model released.

Jeff Rotman / Orangespine unicornfish (Naso lituratus) profile portrait, Red Sea, Egypt.

Alex Mustard,Alex Mustard / Veined octopus (Amphioctopus marginatus) shelters in discarded coconut shell. Lembeh Strait, North Sulawesi, Indonesia. Molucca Sea.

Michael Pitts,Michael Pitts / Aerial of Kossol Passage, Kossol Reef, Palau Islands, North Pacific Ocean.

Doc White / Blue Whales (Balaenoptera musculus) throat inflated, filter feeding at sea surface. California, USA. Sequence 1 of 2.

Mark Carwardine / Mackerel scad (Decapterus macarellus) Guadalupe Island, Mexico (North Pacific)

Mark Carwardine / Great white shark (Carcharodon carcharias) underwater, Guadalupe Island, Mexico (North Pacific)

Mark Carwardine / Tailfin of Great white shark (Carcharodon carcharias) underwater, Guadalupe Island, Mexico (North Pacific)

Mark Carwardine / Great white shark (Carcharodon carcharias) underwater, Guadalupe Island, Mexico (North Pacific)

Doug Perrine / Hawaiian / Gray's / Long-Snouted Spinner Dolphins (Stenella longirostris longirostris) with mother and young calf. Keauhou, Kona, Hawaii, Central Pacific Ocean.

Doug Perrine / Green sea turtle (Chelonia mydas) being cleaned of algae by Yellow tangs / surgeonfish (Zebrasoma flavescens), Puako, Kona, Hawaii, USA, June, Endangered species

Doug Perrine / Green sea turtle (Chelonia mydas) cleaned of algae by Yellow tangs / surgeonfish (Zebrasoma flavescens), Puako, Kona, Hawaii, USA, June, Endangered species

Juergen Freund / Schooling Silverside fish (Antherinidae) split level with karst limestone walls, West Papuan fisherman in boat, North Raja Ampat, West Papua, Indonesia, February 2002.

Juergen Freund / Schooling Silverside fish (Antherinidae) split level with karst limestone walls, fan coral and featherstar, North Raja Ampat, West Papua, Indonesia, February 2002.

Juergen Freund / Salp (Salpidae) colony with diver in the background, North Sulawesi, Indonesia.

Juergen Freund / Blue sea star on massive Boulder coral (Gardineroseris planulata) North Sulawesi, Indonesia. This coral species is normally found from the Red Sea to Central America, and is relatively uncommon in the...

Juergen Freund / Coral reef landscape with abundant whip corals, Blue sea stars and hard coral, North Sulawesi, Indonesia, October 2009.

Juergen Freund / Diver observing Coral razor / Shrimp fish (Aeoliscus strigatus) camouflaged amongst whip coral on coral reef, North Sulawesi, Indonesia. Model released.

Juergen Freund / Large round Brain coral (Platygyra lamellina) on coral reef, North Sulawesi, Indonesia.

Juergen Freund / Large round Brain coral (Platygyra lamellina) on coral reef, North Sulawesi, Indonesia.

Juergen Freund / Shoal of schooling Coral razor / Shrimp fish (Aeoliscus strigatus) with diver on hard coral reef, North Sulawesi, Indonesia.

Juergen Freund / Brown tube sponge (Agelas tubulata) in the reef, North Sulawesi, Indonesia.

Juergen Freund / Whitemargin stargazer (Uranoscopus sulphureus) half hidden in the sand. Lembeh Strait, North Sulawesi, Indonesia

Juergen Freund / Giant manta ray (Manta birostris) at a cleaning station, seen from behind. North Raja Ampat, West Papua, Indonesia

Juergen Freund / Giant manta ray (Manta birostris) at a cleaning station. North Raja Ampat, West Papua, Indonesia.

Juergen Freund / Eyed / Leopard sea cucumber (Bohadschia argus), close-up of the skin. Lembeh Strait, North Sulawesi, Indonesia.

Juergen Freund / Soft coral (Alcyonacea) in the shallow mangroves with diver, split level. North Raja Ampat, West Papua, Indonesia, February 2010

Juergen Freund / Coconut / Veined octopus (Octopus marginatus) hiding in its shell home. Lembeh Strait, North Sulawesi, Indonesia.

Juergen Freund / Coconut / Veined octopus (Octopus marginatus) in a bottle cap getting a new shell to use as its home. Lembeh Strait, North Sulawesi, Indonesia.

Juergen Freund / Giant manta ray (Manta birostris) at a cleaning station with diver swimming behind it. North Raja Ampat, West Papua, Indonesia.

Juergen Freund / Fallen mangrove leaves adding to detritus in the soil. North Raja Ampat, West Papua, Indonesia, February 2010.

Juergen Freund / Coconut / Veined octopus (Octopus marginatus) hiding in its bottle cap home, using a shell as a door. Lembeh Strait, North Sulawesi, Indonesia.

Juergen Freund / Coconut octopus / Veined octopus (Octopus marginatus) in its shell home. Lembeh Strait, North Sulawesi, Indonesia.

Juergen Freund / Light streaming into a shallow cave in a dive site called The Passage, with a diver swimming up towards the foliage visible above. North Raja Ampat, West Papua, Indonesia, February 2010. Model release...

Juergen Freund / West Papuan fishermen in their outrigger houseboat over the shallow reef. North Raja Ampat, West Papua, Indonesia, February 2010