Sandesh Kadur / Wild Gaur (Bos gaurus) with birds on skin, feeding on insects, Western Ghats, Southern India

Alex Mustard / Pederson cleaner shrimp (Periclimenes pedersoni) cleaning the eye of a Nassau grouper (Epinephelus striatus), Bloody Bay Wall, Little Cayman, Cayman Islands. British West Indies, Caribbean Sea.

Alex Mustard / Glasseye snapper (Heteropriacanthus cruentatus) head portrait with a cleaning Goby (Gobiosoma genie) East End, Grand Cayman, Cayman Islands, British West Indies, Caribbean Sea.

Patricio Robles Gil / Silhouetted Capivara / Capibara (Hydrochoerus hydrochaeris) with Cattle Tyrant (Machetornis rixosa), which feeds on flies approaching the Capibara. Parana, Southern Brazil.

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 / Manta rays (Manta birostris) at cleaning station being cleaned by wrasses, Moluccas Islands, Indonesia.

Juergen Freund / Coleman shrimp (Periclimenes colemani) on a Fire urchin (Asthenosoma varium) Moluccas Islands, Indonesia.

Juergen Freund / Spine-cheek anemonefish (Premnas biaculeatus) with baby amongst anemone tentacles, Bali, Indonesia, Indo-pacific.

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

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

Juergen Freund / Carrier / Sea urchin crab (Dorippe frascone) carrying a fire urchin as a deterrent to predators. Lembeh Strait, North Sulawesi, Indonesia

Juergen Freund / Denise's pygmy seahorse (Hippocampus denise) in its fan coral. Misool, Raja Ampat, West Papua, Indonesia

Juergen Freund / Clark's anemonefish / Yellowtail clownfish (Amphiprion clarkii) prreing out from anemone tentacles. Misool, Raja Ampat, West Papua, Indonesia.

Juergen Freund / True clownfish / Clown anemonefish (Amphiprion percula) tending its eggs. Misool, Raja Ampat, West Papua, Indonesia

Juergen Freund / Pygmy seahorse (Hippocampus bargibanti) camouflaged in a fan coral. Misool, Raja Ampat, West Papua, Indonesia.

Juergen Freund / Denise's pygmy seahorse (Hippocampus denise) in its fan coral. Misool, Raja Ampat, West Papua, Indonesia,

Juergen Freund / Pygmy seahorse (Hippocampus bargibanti) camouflaged on coral (Muricela sp). Lembeh Strait, North Sulawesi, Indonesia

Juergen Freund / Oceanic sunfish (Mola mola) with bannerfish and angelfish cleaning it. Taken at 42 meters. Nusa Penida, Lesser Sunda Islands, Indonesia,

Juergen Freund / True clownfish / Clown anemonefish (Amphiprion percula) tending its eggs. Misool, Raja Ampat, West Papua, Indonesia0

Georgette Douwma / Pink anemonefish (Amphiprion perideraion) with anemone showing the effects of bleaching. The bleached anemone is almost white, whereas the unbleached anemone is brown due to the presence of symbiotic...

Alex Mustard / Florida manatee (Trichechus manatus latirostrus) being cleaned by blue gill sunfish (Lepomis macrochirus). Three Sisters Spring, Crystal River, Florida. USA. February 2010

Alex Mustard / Giant Pacific Manta Ray (Manta birostris) portrait with Remora fish (Echeneididae) Roca Partida, Revillagigedos Islands, Mexico. East Pacific Ocean. February

Yva Momatiuk & John Eastcott / Cape Buffalo (Syncerus caffer) bull with Red-billed Oxpecker (Buphagus erythrorhynchus) pair, Masai Mara National Reserve, Kenya

Georgette Douwma / Loki whip goby (Bryaninopss loki) on Sea pen (Virgularia gustaviana). Komodo National Park, Indonesia

Georgette Douwma / Sea pen (Virgularia gustaviana) with a small porcelain crab on sandy sea bed, purple form. Rinca, Indonesia.

Anup Shah / Cape buffalo (Syncerus caffer) head portrait of male, with Cattle egret on its back (Bubulcus ibis). Masai Mara National Reserve, Kenya. February.

Doug Perrine / Female Bull sharks (Carcharhinus leucas) in seasonal breeding aggregation with Sharksuckers (Echeneis naucrates) Playa del Carmen, Cancun, Quintana Roo, Yucatan Peninsula, Mexico (Caribbean Sea)

Jeff Rotman / Blacktip shark (Carcharhinus limbatus) with symbiotic Pilot fish (Naucrates ductor) swimming below, Cocos island, Costa Rica - Pacific ocean.

Jeff Rotman / Great White shark (Carcharodon carcharias) swimming with symbiotic Pilot fish (Naucrates ductor) and schooling Mackerel scad (Decapterus macarellus) Guadalupe Island, Mexico, Pacific Ocean.

Doug Allan / Humpback whale (Megaptera novaeangliae) mother and calf, female with Remoras on underside, Vava'u, Kingdom of Tonga, South Pacific, September. Not available for ringtone/wallpaper use.

Richard Du Toit / Hippopotamus (Hippopotamus amphibius) male with Red-billed Oxpecker (Buphagus erythrorhynchus) pair on back, Chobe National Park, Botswana

Fred Bavendam / Whale Shark (Rhincodon typus) with Golden Trevally (Gnathanodon speciosus) group swimming in front of its mouth, Exmouth, Australia

Juergen Freund / Soft coral crab / Dendronephthya crab (Hoplophrys oatesii) camouflaged on the tip of a soft coral. Indo-pacific

Pete Oxford / Steel pompano fish (Trachinotus stilbe) cleaning Galapagos green turtle (Chelonia mydas agassizi) off Wolf Island, Galapagos Islands

Luis Quinta / Devil ray {Mobula tarapacana} with remora, Azores, Atlantic

Hiroya Minakuchi / Pink Anemonefish (Amphiprion perideraion) in Magnificent Sea Anemone (Heteractis magnifica) host tentacles, Celebes Sea

Georgette Douwma / Clown anemonefish (Amphiprion percula) amongst tentacles of a blue variety of anemone (Stichodactyla gigantea) Raja Ampat, West Papua, Indonesia.

Norbert Wu / Clown Anemonefish (Amphiprion ocellaris) among stinging tentacles of anemone, Komodo Island, Indonesia

Georgette Douwma / Lyretail anthias or Goldie (Pseudanthias squamipinnes) male being cleaned by a Cleaner wrasse (Labroides dimidiates). Rinca, Indonesia

Georgette Douwma / Red soldierfish (Myripristis murdjan) being cleaned by a Bluestreak cleaner wrasse (Labroides dimidiatus), Andaman Sea, Thailand

Tim Laman / Pink anmonefish (Amphiprion perideraion) in anemone on coral reef in Borneo. Sipadan Island, Sabah, Malaysia.

Tim Laman / Two false clown anemonefish (Amphiprion ocellaris) amongst tentacles of sea anemone, Wakatobi Islands, Sulawesi, Indonesia.

Tim Laman / Pink anemonefish (Amphiprion perideraion) amongst tentacles of Sea anemone, Indo-pacific

Anup Shah / Banded mongoose {Mungos mungo} sniffing around the head of a resting Warthog for insects{Phacochoerus aethiopicus} East Africa

Michael Durham / Honey Bee (Apis mellifera) with pollen baskets taking flight from garden flower

Juergen Freund / Anemone crab {Neopetrolisthes ohshimai} in sea anemone, Indo Pacific

Tony Heald / Hippopotamus {Hippopotamus amphibius} with Red billed oxpeckers on head, Moremi Wildlife Reserve, Botswana

Jeff Rotman / Emperor Shrimp (Periclimenes imperator / Zenopontonia rex) living inside gills of Spanish Dancer Nudibranch (Hexabranchus sanguineus). Egypt, Red Sea.

Mitsuaki Iwago / Cape Buffalo (Syncerus caffer) eyeing Red-billed Oxpecker (Buphagus erythrorhynchus), Serengeti National Park, Tanzania

Doug Perrine / Oceanic whitetip shark (Carcharhinus longimanus) with pilot fish (Naucrates ductor) Kona Coast, Hawaii, Central Pacific Ocean

Anup Shah / Banded mongoose {Mungos mungo} foraging for parasites on skin of Warthog {Phacochoerus aethiopicus} Queen Elizabeth NP, Uganda

Anup Shah / Banded mongoose {Mungos mungo} foraging for parasites on skin of Warthog {Phacochoerus aethiopicus} Queen Elizabeth NP, Uganda

Anup Shah / Banded mongoose {Mungos mungo} foraging for parasites on skin of Warthog {Phacochoerus aethiopicus}, Queen Elizabeth NP, Uganda

Anup Shah / Banded mongoose {Mungos mungo} foraging for parasites on skin of Warthog {Phacochoerus aethiopicus} Queen Elizabeth NP, Uganda

Anup Shah / Banded mongoose {Mungos mungo} foraging for parasites on skin of Warthog {Phacochoerus aethiopicus} Queen Elizabeth NP, Uganda

Chris Newbert / Blackfinned Clownfish (Amphiprion percula) in a Magnificent Sea Anemone (Heteractis magnifica) 40 feet deep, Solomon Islands

Pete Oxford / Cape Buffalo (Syncerus caffer) herd with Cattle Egret (Bubulcus ibis) flock in clearing, Africa

Doug Perrine / Pink anemonefish {Amphiprion perideraion} on host sea anemone {Heteractis magnifica} Great Barrier Reef, Queensland, Australia

Juergen Freund / Damselfish (Pomacentridae) protecting its sponge, Caribbean Cuba

Brent Hedges / Giant moray eel with Cleaner wrasse fish{Gymnothorax javanicus} Papua New Guinea

Jean E. Roche / Wild horse (Equus caballus) grazing with Cattle egret (Bubulcus ibis) perched on back. Camargue, France.

Doug Perrine / Pink anemonefish {Amphiprion perideraion} amongst Magnificent sea anemone, Palau Micronesia

Pete Oxford / Cattle Egret perched on back of African Elephant (Loxodonta africana) Amboseli NP Kenya

Georgette Douwma / Giant moray eel with Cleaner wrasse {Gymnothorax javanicus} Red Sea

Georgette Douwma / False clown anemonefish {Amphiprion ocellaris} in anemone. Digital Composite, Andaman sea

Anup Shah / Reticulated giraffe {G. c. reticulata} with oxpeckers, Masai Mara Kenya

Mitsuaki Iwago / Black Rhinoceros (Diceros bicornis) with Red-billed Oxpecker (Buphagus erythrorhynchus), Serengeti National Park, Tanzania

Chris Newbert / Pink Anemonefish (Amphiprion perideraion) in a Magnificent Sea Anemone (Heteractis magnifica), Papua New Guinea

Fred Bavendam / Goby (Amblyeleotris sp) keeping watch while a Snapping Shrimp (Alpheus randalli) excavates their shared burrow, Bali, Indonesia

Tui De Roy / Marine Iguana (Amblyrhynchus cristatus) breeding male basking with Sally Lightfoot Crab (Grapsus grapsus) scavenging dead skin, Hood Island, Galapagos Islands, Ecuador

Chris Newbert / Blackfinned Clownfish (Amphiprion percula) in bleached Magnificent Sea Anemone (Heteractis magnifica) host, Papua New Guinea

Chris Newbert / Scarlet Cleaner Shrimp (Lysmata amboinensis) pair cleaning a Moray Eel (Gymnothorax ocellatus) 80 feet deep, Solomon Islands

Norbert Wu / Green Sea Turtle (Chelonia mydas) being cleaned by Yellow-eyed Surgeonfish (Ctenochaetus strigosus), Hawaii

Richard Du Toit / Red-billed Oxpecker (Buphagus erythrorhynchus) on Impala (Aepyceros melampus) male, Kruger National Park, South Africa

Neil Lucas / Euglossine bee {Euglossinae} at orchid in rainforest, Panama. Bee pollinates flower.

Anup Shah / Impala (Aepyceros melampus) chewing with Oxpecker bird hunting for insects. Masai Mara NR, Kenya, East Africa

Mitsuaki Iwago / Black Rhinoceros (Diceros bicornis) grazing in grassland surrounded by a flock of Cattle Egrets (Bubulcus ibis), Ngorongoro Crater, Tanzania

Mitsuaki Iwago / Black Rhinoceros (Diceros bicornis) with Cattle Egret (Bubulcus ibis) on its back, Ngorongoro Crater, Tanzania

Shin Yoshino / Yellow-billed Oxpecker (Buphagus africanus) trio sitting on Cape Buffalo's (Syncerus caffer) head, Kenya

Mitsuaki Iwago / Hippopotamus (Hippopotamus amphibius) with Yellow-billed Oxpecker (Buphagus africanus), Serengeti National Park, Tanzania

Mitsuaki Iwago / Black Rhinoceros (Diceros bicornis) mother and baby with Red-billed Oxpeckers (Buphagus erythrorhynchus), Ngorongoro Crater, Tanzania

Mary McDonald / Broad billed hummingbird (Cynanthus latirostris) AZ, USA Madera Canyon, Arizona

Michael & Patricia Fogden / Green-crowned Brilliant (Heliodoxa jacula) hummingbird juvenile male feeding at and pollinating Ginger (Costus montanus) flowers, Monteverde Cloud Forest Reserve, Costa Rica

Michael & Patricia Fogden / Purple-throated Mountain-gem (Lampornis calolaemus) hummingbird female feeding at and pollinating epiphytic Orchid flowers (Elleanthus sp), Monteverde Cloud Forest Reserve, Costa Rica

Michael & Patricia Fogden / Green Violet-ear (Colibri thalassinus) hummingbird feeding at and pollinating flowers of epiphytic Heath (Macleania insignis), Monteverde Cloud Forest Reserve, Costa Rica

Michael & Patricia Fogden / Green Violet-ear (Colibri thalassinus) hummingbird feeding on Heath (Cavendishia complectens) flowers, cloud forest, Costa Rica

Michael & Patricia Fogden / Rufous-tailed Hummingbird (Amazilia tzacatl) feeding on Hamelia flowers, Costa Rica

Michael & Patricia Fogden / Coppery-headed Emerald (Elvira cupreiceps) hummingbird male feeding on and pollinating Shiney Maxillaria (Maxillaria fulgens) in cloud forest, Costa Rica

Michael & Patricia Fogden / Yucca Moth (Tegeticula yuccasella) pollinating Yucca flower (Yucca torreyi) and ovipositing, Mexico

Konrad Wothe / Cattle Tyrant (Machetornis rixosa) on Capybara (Hydrochoerus hydrochaeris), Pantanal, Brazil

Birgitte Wilms / Pink Anemone fish (Amphiprion perideraion) in host Magnificent Sea Anemone