Alex Mustard / Yellowtail tang (Zebrasoma xanthurum) male and female turn belly to belly during spawning to ensure fertilization. Temple, Ras Umm Sid, Sharm El Sheikh, Sinai, Egypt. Red Sea. This action is very fast...

Alex Mustard / Southern stingray (Dasyatis americana) two swimming over sand bar, under stormy sky. Grand Cayman, Cayman Islands. British West Indies.

Alex Mustard / Dugong (Dugong dugon) male and juvenile Golden trevally (Gnathanodon speciosus) swimming over Seagrass (Halophila stipulacea) meadow. Marsa Nabaa, Marsa Alam, Egypt.

Alex Mustard / Green turtle (Chelonia mydas) resting on sea floor and two juvenile Golden trevally (Gnathanodon speciosus). Marsa El Shouna, Marsa Alam, Egypt.

Alex Mustard / Oceanic whitetip shark (Carcharhinus longimanus) swimming close to surface. Brothers Islands, Egypt.

Shane Gross / Flying fish (Exocoetidae) in Sargasso Sea, Atlantic Ocean.

Shane Gross / Caribbean reef shark (Carcharhinus perezi), two from below, one close up. Caribbean Sea off Gardens of the Queen National Park, Cuba.

Alex Mustard / Whale shark (Rhincodon typus) close to the camera with a golden trevally fish (Gnathanodon speciosus) and outline of another whale shark behind , in the plankton-rich green waters of La Paz bay, Baja...

Franco Banfi / School of Munk's devil ray, pygmy devil ray, (Mobula munkiana), feeding on plankton at night, photographed on a long exposure, Espiritu Santo Island, Sea of Cortez, Baja California, Mexico, East Pacif...

Shane Gross / Almaco jack (Seriola rivoliana) uses a discarded fishing net, drifting in the open ocean as shelter. The Bahamas.

Nick Hawkins / Blue shark (Prionace glauca) with a pair of pilot fish (Naucrates ductor) off Halifax, Nova Scotia, Canada. July.

David Pattyn / Great crested grebe (Podiceps cristatus) adult with freshly caught fish. Tench (Tinca tinca) to feed to its young chick, Valkenhorst Nature Reserve, Valkenswaard, The Netherlands, June

Remi Masson / Group of Barbels (Barbus barbus) spawning, River Rhone, Rhone-Alpes, France, April.

Remi Masson / Group of Nase (Chondrostoma nasus) and Barbels (Barbus barbus) spawning, River Rhone, Rhone-Alpes, France, April.

Remi Masson / Shoal of Nase (Chondrostoma nasus) spawning, River Ain, Rhone-Alpes, France, April.

Konrad Wothe / Chub (Squalius cephalus) trying to catch a Banded demoiselle (Calopteryx splendens), Bavaria, Germany, June.

David Fleetham / California yellowtail (Seriola lalandi dorsalis) Guadalupe Island, Mexico.

Jordi Chias / Blue spotted trevally (Caranx bucculentus) hunting small fish in the reef, South Ari Atoll, Maldives, Indian Ocean.

Michel Roggo / Fishes in the Sungai Melinau river, Gunung Mulu National Park, Sarawak, Borneo, Malaysia. Photographed for The Freshwater Project.

Jordi Chias / European barracuda (Sphyraena sphyraena) and Bluefish (Pomatomus saltatrix) circling baitball of Atlantic horse mackerel (Trachurus trachurus) Formigas Islets, Azores. Finalist in the Underwater Categ...

John Waters / Shoal of Minnows (Phoxinus phoxinus) swimming and feeding in the River Wye, Wales, UK, July.

Alex Mustard / Warty / Clown frogfish (Antennarius maculatus) male portrait, Anilao, Batangas, Luzon, Philippines, March

Alex Mustard / Ribbon sweetlips (Plectorhinchus polytaenia) USAT Liberty Wreck, Tulamben, Bali, Indonesia. Java Sea

Alex Mustard / Brandt's cormorant (Phalacrocorax penicillatus) hunts for a meal in a school of Pacific chub mackerel (Scomber japonicus) beneath an oil rig. Eureka Rig, Los Angeles, California, USA, September

Alex Mustard / Tompot blenny (Parablennius gattorugine) portrait, Swanage Pier, Swanage, Dorset, UK, English Channel, August

Richard Robinson / Shortfin mako shark (Isurus oxyrinchus) profile portrait, just below surface, off the West Coast of Auckland, New Zealand, February

Tony Wu / Killer whale / Orca (Orcinus orca) large adult male stalking a large school of Herring (Clupea harengus) in shallow water, Norway, February

Jordi Chias / Two male Dusky groupers (Epinephelus marginatus) fighting for territory during mating season at 'baixa do meros', a small pinnacle at Formigas islets Protected area, near Santa Maria Island, Azores. F...

Alex Mustard / Brandt's cormorant (Phalacrocorax penicillatus) hunts for a meal in a school of Pacific chub mackerel (Scomber japonicus), beneath an oil rig. Eureka Rig, Los Angeles, California, United States of Ame...

Alex Hyde / Fishing spider (Trechalea) waiting to catch a Killifish (Cyprinodontiformes) in a rainforest stream at night, Central Caribbean foothills, Costa Rica.

Alex Mustard / Great white shark (Carcharodon carcharias) from above. Guadalupe Island, Baja California, Mexico. East Pacific Ocean

Alex Mustard / Leafy seadragon (Phycodurus eques). Wool Bay Jetty, Edithburgh, Yorke Peninsula, South Australia.

Alex Mustard / Spotlight goby (Gobiosoma louisae) looking out from inside a Yellow tube sponge (Aplysina fistularis), growing on a coral reef. Bloody Bay Wall, Little Cayman, Cayman Islands, British West Indies. Car...

Alex Mustard / Nassau grouper (Epinephelus striatus) yawning on a coral reef drop off. San Salvador island, Bahamas. Bahamas Sea, Tropical West Atlantic Ocean.

Alex Mustard / Great white sharks (Carcharodon carcharias) males beneath the surface. Guadalupe Island, Baja California, Mexico. East Pacific Ocean

Doug Perrine / Pygmy shark (Euprotomicrus bispinatus) portrait, captive. Kona, Hawaii. Central Pacific Ocean.

Doug Perrine / Pygmy shark (Euprotomicrus bispinatus) portrait, captive. Kona, Hawaii. Central Pacific Ocean. Digitally manipulated image.

Chris & Monique Fallows / Mako shark (Isurus oxyrinchus) near surface, Cape Point, South Africa, March 2015

Chris & Monique Fallows / Great white shark (Carcharodon carcharias) predating Cape fur seal (Arctocephalus pusillus) Seal Island, False Bay, South Africa, July. Sequence 3 of 3

Chris & Monique Fallows / Great white shark (Carcharodon carcharias) split level view, New Zealand, March.

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

Alex Mustard / Great hammerhead shark (Sphyrna mokarran) female at night with Bar jacks (Caranx ruber), South Bimini, Bahamas. The Bahamas National Shark Sanctuary. Gulf Stream, West Atlantic Ocean.

Alex Mustard / Great hammerhead shark (Sphyrna mokarran) swimming over a sandy seabed, accompanied by Rainbow runners (Elagatis bipinnulata) South Bimini, Bahamas. The Bahamas National Shark Sanctuary. Gulf Stream,...

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

Alex Mustard / Whitetip shark (Carcharhinus longimanus) head on beneath the surface. Rocky Island, Egypt. Red Sea

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

Jordi Chias / Angular roughshark (Oxynotus centrina) a deepsea species living at 80-300m depth, caught by fishermen and released, Costa Brava, Catalunya, Spain, Mediterranean Sea

Jordi Chias / Split level view of Blue shark (Prionace glauca) at surface at sunset, Azores Islands, Portugal, Atlantic Ocean

Jordi Chias / Giant Manta (Manta birostris) with Remoras (Remora brachyptera) attached to both wings, offshore Santa Maria Island, Azores, Atlantic Ocean

Jordi Chias / Mobula / Chilean devil ray (Mobula tarapacana) with remora (Remora brachyptera) and Amberjacks (Serila dumerilli) Santa Maria Island, Azores, Atlantic Ocean

Pete Oxford / Nurse Shark (Ginglymostoma cirratum) Hol Chan Marine Reserve, Belize Barrier Reef, Belize.

Pete Oxford / Whale Shark (Rhincodon typus) feeding at Bagan (floating fishing platform), Cenderawasih Bay, West Papua, Indonesia. Winner of the Man and Nature Portfolio Award in the Terre Sauvage Nature Images Aw...

Pete Oxford / Whale Shark (Rhincodon typus) and Golden trevally (Gnathanodon speciosus) Cenderawasih Bay, West Papua, Indonesia.

Pete Oxford / Whale shark (Rhincodon typus) front view portrait, Cenderawasih Bay, West Papua. Indonesia.

Pete Oxford / Whale Shark (Rhincodon typus) close up of spotted skin, with Golden trevally (Gnathanodon speciosus) Cenderawasih Bay, West Papua, Indonesia.

Pete Oxford / Whale shark (Rhincodon typus) and scuba divers seen from below, Cenderawasih Bay, West Papua. Indonesia.

Pete Oxford / Whale shark (Rhincodon typus) and scuba divers seen from below, Cenderawasih Bay, West Papua. Indonesia. Winner of the Man and Nature Portfolio Award in the Terre Sauvage Nature Images Awards Competit...

Pete Oxford / Whale shark (Rhincodon typus) Cenderawasih Bay, West Papua. Indonesia.

Ann & Steve Toon / Atlantic salmon (Salmo salar) leaping on upstream migration, River Tyne, Hexham, Northumberland, UK, November

Georgette Douwma / Chocolate chip sea star o (Protoreaster nodosus) on sandy bottom. Mabul, Malaysia.

Bence Mate / Grey Heron (Ardea cinerea) with large carp fish in beak, Lake Csaj, Kiskunsagi National Park, Pusztaszer, Hungary. February.

Luis Quinta / Imperial blackfish (Schedophilus ovalis) sheltering under discarded fishing ropes drifting off Pico island, Azores, Portugal, May.

Pascal Kobeh / Long-snouted seahorse (Hippocampus guttulatus) with prehensile tail twined round seagrass, Etang de Thau Lagoons, Languedoc-Roussillon, France.

Loic Poidevin / Grizzly bear (Ursus arctos horribilis) mother watching cub catching salmon, Katmai National Park, Alaska, USA, August

Loic Poidevin / Grizzly bear (Ursus arctos horribilis) cubs with salmon, Katmai National Park, Alaska, August. Small reproduction only.

Loic Poidevin / Grizzly bear (Ursus arctos horribilis) cubs with salmon, Katmai National Park, Alaska, August. Small reproduction only.

Tony Wu / Twinspot snapper (Lutjanus bohar) shoal rushing up to spawn, releasing a cloud of milky white sperm and eggs in the water column. Caroline Islands, Palau, November.

Tony Wu / Twinspot snapper (Lutjanus bohar) engaged in a mass spawning aggregation early in the morning. Caroline Islands, Palau. April. Winner of Underwater category, Wildlife Photographer of the Year 2016.

Sven Zacek / Otter (lutra lutra) eating Gudgeon (Gobio gobio) in Southern Estonia, January.

Alex Mustard / Group of predators hunting together, in an example of 'Nuclear foraging'. The Moray eel (Gymnothorax javanicus) flushes out prey, and is followed by a Napolean wrasse (Cheilinus undulatus) and a Bluef...

Doug Perrine / Barjacks (Caranx ruber), Yellowtail snapper (Ocyurus chrysurus), and Sergeant major damselfish (Abudefduf saxatilis) swimming around wreck of bow gun on C-58 shipwreck off Puerto Morelos, near Cancun,...

Solvin Zankl / Illuminated netdevil (Linophryne arboritera), female specimen, from deepsea Atlantic Ocean near Cape Verde at a depth of 1900m.

Alex Mustard / Oceanic whitetip shark (Carcharhinus longimanus) accompanied by pilotfish (Naucrates ductor) as it cruises beneath the surface of the Red Sea, close to Little Brother Island. The Brothers Islands, Egy...

Aflo / Northern sea nettle (Chrysaora Melanaster) floating, with Mackerel fry ( Carangidae) Izu, Japan. January.

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

Alex Mustard / Shoal of Bar jacks (Caranx ruber) hunting school of Silversides fish (Atherinidae) in coral cavern. East End, Grand Cayman, Cayman Islands, British West Indies. Caribbean Sea.

Alex Mustard / Pair of Bar jacks (Caranx ruber) hunting Silversides (Atherinidae) inside cave. Devil's Grotto, George Town, Grand Cayman, Cayman Islands, British West Indies. Caribbean 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.

Alex Mustard / A long exposure renders Bar jacks (Carangoides ruber) as ghostly trails as they swim around a sponge, on a coral reef, at night. East End, Grand Cayman, Cayman Islands. Overall winner of GDT competiti...

Alex Mustard,Alex Mustard / A signal blenny (Emblemaria hypacanthus) displays its showy dorsal fin as it extends out of its tube home. La Paz, Mexico. Sea Of Cortez, East Pacific Ocean.

Alex Mustard,Alex Mustard / Rainbow trout (Oncorhynchus mykiss) under trees, Capernwray Lake, Lake District, England, UK.

Alex Mustard,Alex Mustard / Whaleshark (Rhincodon typus) swimming and filtering fish eggs from the water. A behaviour known as ram-feeding. Isla Mujeres, Quintana Roo, Yucatan Peninsular, Mexico. Caribbean Sea.

Alex Mustard,Alex Mustard / A female (in front) and male Sockeye salmon (Oncorhynchus nerka) over eggs in their spawning river. Adams River, British Columbia, Canada, October.

Konrad Wothe / Foureyed fish (Anableps anableps) split level view, South America, captive

Franco Banfi,Franco Banfi / Local man looking down at shoal of Bigeye scad (Selar crumenophthalmus) Waigeo island, Raja Ampat, Irian Jaya, West Papua, Indonesia, Pacific Ocean

Sue Daly / Koheru (Decapterus koheru) shoal swiming around diver, Cavalli Islands, New Zealand, February 2013. Model released.

Pascal Kobeh / Parrotfish (Scarus / Chlorurus sp.) sleeping at night, New Caledonia, Pacific Ocean.

Pascal Kobeh / Zebra / Leopard shark (Stegostoma varium) swimming away from the bottom, New Caledonia, Pacific Ocean.

Pascal Kobeh / Three Pygmy seahorses (Hippocampus bargibanti) on a Seafan / Gorgonian (Muricella sp) including one or several pregnant males. New Caledonia, Pacific Ocean

Pascal Kobeh / Four Pygmy seahorses (Hippocampus bargibanti) on a Seafan / Gorgonian (Muricella sp. ) including one or several pregnant males. New Caledonia, Pacific Ocean.

Pascal Kobeh / Ocan Pacifique - Nouvelle caldonie - Gros plan de la tte d'un nason licorne (Naso brevirostris) de nuit Pacific Ocean - New Caledonia - A close-up of the head of a spotted or longnose unicornfish (Na...

Alex Mustard / Scalefin anthias (Pseudanthias squamipinnis) male with a long exposure. Ras Katy, Sharm El Shiekh, Sinai, Egypt. Red Sea. Commended in the GDT Photography competition 2019.

Alex Mustard / Black and white photo of school of Bigeye trevally (Caranx sexfasciatus) form a circular shoal in open water, on the drop off of a coral reef. Ras Mohammed National Park, Sinai, Egypt. Red Sea. Highly...

Alex Mustard / Yellow longsnout seahorse (Hippocampus reidi) female holds onto a sea rod with its prehensile tail, on a coral reef. West Bay, Grand Cayman, Cayman Islands, British West Indies. Caribbean Sea.