Trainers from Tianjiao Special Guard/Security Consultant Ltd. Co. engage trainees dressed in swimming suits as they crawl on the beach during a training session in Sanya, Hainan province January 8, 2012. (Photo by CHINA DAILY/Reuters)

This undated handout picture taken by Tim Samuel and provided through his Instagram account shows a small fish swimming inside the belly of a jellyfish off the coast of Byron Bay in New South Wales, eastern Australia. A fish has been pictured swimming inside a jellyfish off Australia's east coast in a remarkable and rare image that has gone viral, with more than two million online views. Underwater photographer Tim Samuel was in the water with a friend near popular tourist resort Byron Bay in December when they came across the little creature trapped inside the only slightly larger jellyfish. (Photo by Tim Samuel Photography/AFP Photo/Instagram)

In this September 1, 2015 photo, street artists Jenaro de Rosenzweig, left, and Alejandro Revilla pose for a portrait behind a restaurant's window covered with a mural by artist Francisco Munoz, signed with his artist's name below, in the Roma Norte neighborhood of Mexico City. Rosenzweig and Revilla founded the “Street Art Chilango” cooperative in March 2013, which is filling neighborhoods with public art by local street artists. (Photo by Rebecca Blackwell/AP Photo)

A girl swims in floodwaters in Malaysia' s northeastern town of Rantau Panjang, which borders Thailand, on January 5, 2017 Floods in two northeast Malaysian states have now forced almost 23,000 people from their homes and extra relief centres have been opened, rescue officials said on January 4. (Photo by Mohd Rasfan/AFP Photo)

Wild weather drenches tourists, Sydney, Australia on March 7, 2017. A series of photographs as tourists take a soaking on Sydney's iconic Manly Ferry sailing big swells near Sydney's North Head. The Weather Bureau warns of large and powerful surf conditions expected to be hazardous for coastal activities such as rock fishing, swimming and surfing. (Photo by Hugh Peterswald/Pacific Press via ZUMA Wire/Rex Features/Shutterstock)

Humboldt Penguins swim in their pool as a keeper looks on through a spherical window during the annual stocktake press preview at London Zoo in Regents Park in London Monday, January 4, 2016. A requirement of ZSL London Zoo's license, the annual audit takes keepers a week to complete and all of the information is shared with zoos around the world via the International Species Information System, where it's used to manage the worldwide breeding programmes for endangered animals. (Photo by Alastair Grant/AP Photo)

A group of daredevil divers get perilously close to a school of deadly sharks – and one even lies on his back with his arm folded. The relaxed diver swims on his back and almost hugs the shark who is floating directly above him. The freedivers – Carlos Estrabeau, 28, and 29-year-old Ocean Ramsey – are friends with photographer Raul Boesel Jr. Photographer Raul Boesel Jr from Curitiba, Brazil, travelled to West End in the Bahamas to capture images of the giant sharks. (Photo by Raul Boesel/Solent News & Photo Agency)

Swans swim over a lake, with the air temperature at about minus 35 degrees Celsius (minus 31 degrees Fahrenheit) as steam ascends above the water during sunset near the village of Urozhainy, Sovetsky district of Altai region, January 26, 2015. About 600 swans annually migrate to the lake, which is heated by warm springs, where they spend their winter being fed by yagers, which helps them to survive the severe cold. (Photo by Andrei Kasprishin/Reuters)