Merit Prize Winner: “A Well Earned Rest in the Sahara”. This photo of Moussa Macher, our Tuareg guide, was taken at the summit of Tin-Merzouga, the largest dune (or erg) in the Tadrat region of the Sahara desert in southern Algeria. Moussa rested while waiting for us to finish our 45-minute struggle to the top. It only took ten minutes of rolling, running, and jumping to get back down. The Tadrat is part of the Tassili N'Ajjer National Park World Heritage area, famous for its red sand and engravings and rock paintings of cattle, elephants, giraffes, and rhinos that lived there when the climate was milder. Photo location: Summit of Tin-Merzouga, Tadrat, Tassili N'Ajjer National Park, Algeria. (Photo and caption by Evan Cole/National Geographic Photo Contest)

A young anoa, also known as midget buffalo, named Tycoon runs around at the Zoo in Berlin, Germany, on November 9, 2012. (Photo by Maurizio Gambarini/EPA)

“Doctor fish is the name given to two species of fish: Garra rufa and Cyprinion macrostomus. Other nicknames include nibble fish, kangal fish, physio fish and doctorfishen; in non-medical contexts, Garra rufa is called the reddish log sucker. They live and breed in the outdoor pools of some Turkish spas, where they feed on the skin of patients with psoriasis. The fish are like combfishes in that they only consume the affected and dead areas of the skin, leaving the healthy skin to grow, with the outdoor location of the treatment bringing beneficial effects. The spas are not meant as a curative treatment option, only as a temporary alleviation of symptoms, and patients usually revisit the spas every few months”. – Wikipedia

Photo: Visitors to the Aqua Sheko fish therapy spa have their feet exfoliated on June 24, 2010 in London, England. Customers sit with their feet in a tank filled with 100-150 Garra Rufa fish which remove any dead skin by nibbling and sucking. A half hour session is then followed by a foot massage. (Photo by Peter Macdiarmid/Getty Images)

Magdalena Neuner poses in front of mammoth figures during a photocall of the German Biathlon Woman Team at the Archeopark on March 10, 2011 in Khanty-Mansiysk, Russia. On the territory of Archeopark are mammoth sculptural compositions, made of bronze. Mammoths lived in Ugra 70-10 thousand years ago and were members of the Pleistocene, or also called 'the mammoth fauna’. The growth figures exceed the natural factor 2-3 times.

A rickshaw driver looks out the windshield as he drives onto the highway in Mardan, Pakistan January 30, 2017. (Photo by Fayaz Aziz/Reuters)

Wrestler Kairi Hojo jumps at her opponent Mieko satomura during their Stardom female professional wrestling show at Korakuen Hall in Tokyo, Japan, July 26, 2015. Professional women's wrestling in Japan means body slams, sweat, and garish costumes. But Japanese rules on hierarchy also come into play, with a culture of deference to veteran fighters. The brutal reality of the ring is masked by a strong fantasy element that feeds its popularity with fans, most of them men. (Photo by Thomas Peter/Reuters)

An armed forces members patrol during an operation against drug dealers in Vila Kennedy slum in Rio de Janeiro, March 7, 2018. (Photo by Pilar Olivares/Reuters)

Dead leaf or almost by Guilhem Duvot. Taken in Nován Stráž, Slovakia. Describe what is pictured? A dead leaf grasshopper. How does this image fit with the theme of the competition? The perfect camouflage – nature is amazing. I saw the grasshopper only because it jumped. (Photo by Guilhem Duvot/Royal Society of Biology)