Klaus Echle / Red Fox (Vulpes vulpes) walking along a fallen trunk, silhouetted in misty forest. Black Forest, Germany, November.

David Shale / Female Anglerfish fanfin seadevil (Caulophryne jordani) - Deep sea species from Atlantic Ocean, found at 700-3000m.

Shane Gross / American crocodile (Crocodylus acutus) with open mouth amongst Seagrass (Alismatales). Gardens of the Queen National Park, Cuba.

Ann & Steve Toon / Lion (Panthera leo) male snarling at night, Zimanga private game reserve, KwaZulu-Natal, South Africa, September

Emanuele Biggi / Peruvian Tarantula (Pamphobeteus sp.) and Humming Frog (Chiasmocleis royi) together, Los Amigos Biological Station, Madre de Dios, Amazonia, Peru. These species have a commensal relationship. The tara...

Emanuele Biggi / Peruvian Tarantula (Pamphobeteus sp.) adult, walking over Humming Frog (Chiasmocleis royi) without preying on it. Los Amigos Biological Station, Madre de Dios, Amazonia, Peru. These species have a com...

David Fleetham / Great white shark (Carcharodon carcharias) breaking surface with mouth open. Guadalupe Island, Mexico.

Claudio Contreras / American crocodile (Crocodylus acutus), underwater, Jardines de la Reina / Gardens of the Queen National Park, Caribbean Sea, Ciego de Avila, Cuba, January. Vulnerable species.

Nick Hawkins / Common vampire bat (Desmodus rotundus) exiting cave, Costa Rica, March 2014.

Nick Hawkins / Common vampire bats (Desmodus rotundus) roosting in cave, Costa Rica.

Ingo Arndt / Prairie rattlesnake (Crotalus viridis viridis), threat display, South Dakota, USA September. Sequence 1 of 3

Ingo Arndt / American Alligator (Alligator mississippiensis) split level, Everglades, USA, January.

Cyril Ruoso / Golden monkey (Rhinopithecus roxellana) male showing canine teeth, Qinling Mountains, China.

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

Will Burrard-Lucas / Spotted hyena (Crocuta crocuta) at night, taken with remote camera. Liuwa Plain National Park, Zambia. December

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

Steven Kazlowski / Polar bear (Ursus maritimus) portrait against sky at sunset, Bernard Spit, off the 1002 Area, Arctic National Wildlife Refuge, North Slope, Alaska, USA, September. Vulnerable species.

Jan Hamrsky / Diving beetle (Colymbetes fuscus) close up head portrait. Europe, June. Controlled conditions.

Alex Hyde / Greater horseshoe bat (Rhinolophus ferrumequinum) roosting in cave. Croatia. November.

Nick Garbutt / Darwin's hawkmoth (Xanthopan morgani praedicta) showing extraordinarily long coiled tongue. Andasibe-Mantadia National Park, Madagascar.

Alex Hyde / House spider female (Tegenaria sp.) in garden shed. Derbyshire, UK, March. Highly Commended in the Urban Wildlife category of the 2015 British Wildlife Photography Awards (BWPA) Competition.

Jiri Lochman / Bolas spider (Dicrostichus furcatus / Ordgarius furcatus) female with bolas, a blob of silk at end of line used to swing at prey, only used by females. Bolas spiders also produce pheromones of specifi...

Solvin Zankl / Ribbon sawtail fish (Idiacanthus fasciola) from Atlantic Ocean, at a depth of 800-1000m.

Solvin Zankl / Frilled shark (Chlamydoselachus anguineus) specimen with mouth open, from Atlantic Ocean, at a depth of 729m.

Nick Upton / Adult Herring gull (Larus argentatus) scavenging left over food, St.Ives, Cornwall, UK, June. Editorial use only.

Andy Rouse / Mountain gorilla (Gorilla beringei) silverback yawning with mouth wide open. Rwanda.

Franco Banfi / Green anaconda (Eunectes murinus) underwater, flicking tongue, Formoso River, Bonito, Mato Grosso do Sul, Brazil

Shattil & Rozinski,Shattil & Rozinski / Black bear (Ursus americanus) cub climbing a fence, Minnesota, USA, May.

Alex Mustard,Alex Mustard / Wolf fish (Anarhichas lupus) face portrait. Gardur, south west Iceland. North Atlantic Ocean.

Claudio Contreras,Claudio Contreras / Black-axil Chromis (Chromis atripectoralis) blurred motion photograph. Bilang Bilangang Island, Danajon Bank, Central Visayas, Philippines, April

Solvin Zankl / Dragonfish (Melanostomias melanops) - deep sea specimen from 2000m depth, nr Cape Verde Islands, North Atlantic

Solvin Zankl / Dragonfish (Melanostomias melanops) - deep sea specimen from 2000m depth, nr Cape Verde Islands, North Atlantic

Solvin Zankl / Dragonfish (Melanostomias biseriatus), deepsea specimen from 2000m depth, nr Cape Verde Islands, North Atlantic

Solvin Zankl / Deepsea Blackdevil fish (Melanocetus murrayi) female anglerfish specimen.

Solvin Zankl / Viperfish (Chauliodus sloani) - deep sea specimen from Portugal

Ernie Janes / Barn owl (Tyto alba) in flight, viewed through car windscreen at night, Norfolk, UK, model released. Digital composite

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

Bernard Castelein / Garden spider (Araneus diadematus) hanging on web with shadow behind, Belgium

Solvin Zankl / Murrays abyssal anglerfish (Melanocetus murrayi) Atlantic ocean. A deep-sea fish with bioluminescent lure used to attract prey. The bioluminescence is produced by symbiotic bacteria; these bacteria ar...

David Shale / Portrait of Fangtooth {Anoplogaster cornuta} Atlantic

Michael D. Kern / Green tree python snake {Morelia / Chondopython viridis} portrait, captive, occurs Papua New Guinea and Indonesia

Solvin Zankl / Long-nosed whip snake coming towards camera {Ahaetulla prasina} Sulawesi, Indonesia

Alex Mustard / Bluestreak cleaner wrasse (Labroides dimidiatus) cleans among the sharp teeth of a predatory roving coral grouper (Plectropomus pessuliferus) beneath an overhang on a coral reef. Ras Mohammed National...

Sergio Hanquet / Fangtooth moray (Enchelycore anatina) with open mouth, portrait. Tenerife, Canary Islands.

Sergio Hanquet / Fangtooth moray (Enchelycore anatina), close up of eye and open mouth with teeth. Tenerife, Canary Islands.

Shane Gross / Green sea turtle (Chelonia mydas) with open mouth, swimming below surface. Eleuthera, Bahamas.

Ernie Janes / Brown rat (Rattus norvegicus)many crowded together in farm barn.

Chris Mattison / Cyprus tarantula (Chaetopelma karlamani). Cyprus. March.

Shane Gross / American crocodile (Crocodylus acutus) with open mouth in Seagrass (Alismatales) meadow, reflected on water surface. Gardens of the Queen National Park, Cuba.

Pascal Kobeh / Stargazer (Uranoscopus sulphureus) half buried in the sand, Sulu sea, Philippines

Suzi Eszterhas / Komodo dragon (Varanus komodoensis) yawning, Komodo National Park, Indonesia

David Fleetham / Painted frogfish (Antennarius pictus) with first dorsal spine and lure extended to attract prey. Dumaguete, Philippines.

Emanuele Biggi / Peruvian Tarantula (Pamphobeteus sp.) young communally feeding on a treefrog (Scinax ictericus) left for them by their mother, Los Amigos Biological Station, Madre de Dios, Amazonia, Peru.

Emanuele Biggi / Peruvian Tarantula (Pamphobeteus sp.) adult and young emerging from their communal burrow at night, Los Amigos Biological Station, Madre de Dios, Amazonia, Peru.

Emanuele Biggi / Peruvian Tarantula (Pamphobeteus sp.) adult and young emerging from their communal burrow at night, Los Amigos Biological Station, Madre de Dios, Amazonia, Peru.

Emanuele Biggi / Theraphosidae spider, possibly Peruvian Tarantula (Pamphobeteus sp.) young feeding on an Amazon sheep frog (Hamptophryne boliviana). Los Amigos Biological Station, Madre de Dios, Amazonia, Peru.

Emanuele Biggi / Peruvian Tarantula (Pamphobeteus sp.), young individual parasitized by Phoridae fly larvae, Los Amigos Biological Station, Madre de Dios, Amazonia, Peru.

Emanuele Biggi / Peruvian Tarantula (Pamphobeteus sp.). young feeding on a cockroach left for it by its mother, Los Amigos Biological Station, Madre de Dios, Amazonia, Peru.

Emanuele Biggi / Peruvian Tarantula (Pamphobeteus sp.) young emerging from their communal burrow at night, Los Amigos Biological Station, Madre de Dios, Amazonia, Peru.

Emanuele Biggi / Fishing spider (Thaumasia sp.) adult female eating a tadpole, Los Amigos Biological Station, Madre de Dios, Amazonia, Peru.

Emanuele Biggi / Peruvian Tarantula (Pamphobeteus sp.) young and Humming Frog (Chiasmocleis royi) together, Los Amigos Biological Station, Madre de Dios, Amazonia, Peru. These species have a commensal relationship. Th...

Emanuele Biggi / Peruvian Tarantula (Pamphobeteus sp.) young and Humming Frog (Chiasmocleis royi) together, Los Amigos Biological Station, Madre de Dios, Amazonia, Peru. These species have a commensal relationship. Th...

Emanuele Biggi / Peruvian Tarantula (Pamphobeteus sp.) and Humming Frog (Chiasmocleis royi) together, Los Amigos Biological Station, Madre de Dios, Amazonia, Peru. These species have a commensal relationship. The tara...

Emanuele Biggi / Peruvian Tarantula (Pamphobeteus sp.) young commonully feeding on a treefrog (Scinax ictericus) left to them by their mother, while a Humming Frog (Chiasmocleis royi) passes by unharmed, Los Amigos Bi...

Emanuele Biggi / Peruvian Tarantula (Pamphobeteus sp.) adult, walking over Humming Frog (Chiasmocleis royi) without preying on it. Los Amigos Biological Station, Madre de Dios, Amazonia, Peru. These species have a com...

Emanuele Biggi / Peruvian Tarantula (Pamphobeteus sp.) adult, walking over Humming Frog (Chiasmocleis royi) without preying on it. Los Amigos Biological Station, Madre de Dios, Amazonia, Peru. These species have a com...

Werner Bollmann / Brown bear (Ursus arctos) at night, Lentiira, Finland, September.

Staffan Widstrand / Wild Wonders of China / Sichuan golden snub-nosed monkey (Rhinopithecus roxellana) baring his teeth while screaming at the Yangxian Nature Reserve, Shaanxi, China. September

Remi Masson / Giant cave spider (Heteropoda sp.) Sulawesi, Indonesia. One of the worlds largest spider with a leg span of 25 cm

Joao Burini / Brazilian wandering spider (Phoneutria keyserlingi) male, South-east Atlantic forest, Piedade, Sao Paulo, Brazil.

Cyril Ruoso / Chimpanzee (Pan troglodytes verus) 'Jeje' adult male yawning, Bossou, Republic of Guinea.

David Fleetham / Komodo dragons (Varanus komodoensis) on shore with saliva dripping from mouth, Rinca Island, Komodo National Park, Indonesia.

Sylvain Cordier / Redeye Piranha ( Serrasalmus rhombeus / niger ) out of water, close up of teeth, Rio Negro, Amazonas, Brazil.

Sylvain Cordier / Red-bellied piranha or red piranha (Pygocentrus nattereri) out of water, close up of teeth, Rio Negro, Amazonas, Brazil.

Eric Baccega / Chimpanzee (Pan troglodytes schweinfurthii) male, yawning, Kibale National Park, Uganda.

Edwin Giesbers / Black panther / melanistic Leopard (Panthera pardus) baring teeth, captive.

Edwin Giesbers / Black panther / melanistic Leopard (Panthera pardus) baring teeth, captive.

Andy Rouse / Black panther / melanistic Leopard (Panthera pardus) snarling. Captive. Non-ex

Andy Rouse / Black panther / melanistic Leopard (Panthera pardus) standing on dead tree, captive. Non-ex

Andy Rouse / Black panther / melanistic Leopard (Panthera pardus) standing on dead tree, captive. Non-ex

Bert Willaert / Variegated lizardfish (Synodus variegatus), Bismarck Sea, Vitu Islands, West New Britain, Papua New Guinea

Bert Willaert / Variegated lizardfish (Synodus variegatus), Bismarck Sea, Vitu Islands, West New Britain, Papua New Guinea

Paul Williams / Celebes crested macaque / black macaque (Macaca nigra) large adult male yawning on beach, Tangkoko, Sulawesi, Indonesia.

Yashpal Rathore / Sloth bear (Melursus ursinus) low angle portrait, Daroiji Bear Sanctuary, Karnataka, India. Remote camera image.

Emanuele Biggi / Giant huntsman spider (Megaloremmius leo) female, Mitsinjo Nature Reserve, Madagascar.

Alex Mustard / Tiger cardinalfish (Cheilodipterus macrodon) male mouthbrooding eggs in his mouth. Gubal Barge, Gubal Island, Egypt. Strait of Gubal, Gulf of Suez, Red Sea

Lucas Bustamante / Aye Aye (Daubentonia madagascariensis) at night, Palmarium, Atsinanana, Madagascar.

Daniel Heuclin / Crocodile monitor (Varanus salvadorii) portrait, captive, occurs in New Guinea.

Danny Green / Black bears (Ursus americanus) standing on back legs, fighting, Minnesota, USA, June.

Tony Heald / Nile crocodile (Crocodylus niloticus) Chobe National Park, Botswana, June.

Claudio Contreras / Panamic green moray (Gymnothorax castaneus), Socorro Island, Revillagigedo Archipelago Biosphere Reserve (Socorro Islands), Pacific Ocean, Western Mexico, March

Sylvain Cordier / Komodo dragon (Varanus komodoensis) Rinca Island, Indonesia