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.

Kerstin Hinze / Black-bellied hamster (Cricetus cricetus) feeding on yew fruits (Taxus baccata), Vienna, Austria, October.

Alex Mustard / Portrait of Bandcheek wrasse (Oxycheilinus digrammus) taken during the day. Anemone City, Ras Mohammed Marine Park, Gulf of Aqaba, Red Sea. Sinai, Egypt.

Anup Shah / Bornean Orangutan (Pongo pygmaeus wurmbii) mature male 'Tom' close-up portrait showing cheek pad eyes and nose. Camp Leakey, Tanjung Puting National Park, Central Kalimantan, Borneo, Indonesia. June 2...

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

Peter Cairns / 2020VISION / Pair of Gannets (Morus bassanus) mutual preening, Bass Rock, Firth of Forth, Scotland, UK, June. Photographer quote: 'I never get tired of watching gannets. This pair who momentarily lined up in perfe...

Edwin Giesbers / Portrait of Eurasian Jay (Garrulus glandarius) showing colouring on cheek and primary flight feathers. The Netherlands, June.

John Cancalosi / Golden-mantled ground squirrel (Spermophilus lateralis) with very full cheek pouches. Montana, USA, Oct 2010

Doug Gimesy / Platypus (Ornithorhynchus anatinus) researcher taking cheek pouch samples from an anaesthetized platypus that was captured earlier from in the Snowy River, Dalgety, NSW, Australia. Dalgety, NSW, Austr...

Doug Gimesy / Platypus (Ornithorhynchus anatinus) researcher taking cheek pouch samples from an anaesthetized platypus, Snowy River, Dalgety, NSW, Australia. Dartmouth, Victoria, Australia. May 2018. Model relea...

Doug Gimesy / Platypus (Ornithorhynchus anatinus) researcher taking a cheek pouch samples. Dartmouth, Victoria, Australia . May 2018. Model released