Smithsonian National Zoo biologist Leigh Pitsko releases a male lion cub for its swim test in the zoo habitat moat, in Washington May 6, 2014. Four, unnamed ten-week old lion cubs were tested today for their ability to swim and remove themselves from their zoo habitat moat. (Photo by Gary Cameron/Reuters)

A cosplayer uses moving stairs during the first public day of the world's largest computer games fair Gamescom in Cologne, Germany August 23, 2017. (Photo by Wolfgang Rattay/Reuters)

A so-called “Supermoon” dominates the sky while traffic rolls in the streets in Naypyitaw, Myanmar, 03 December 2017. According to the National Aeronautics and Space Administration (NASA) a series of three “Supermoons” – dubbed the “Supermoon trilogy” – will appear in the sky on 03 December 2017, on 01 January 2018 and and 31 January 2018. A “Supermoon” commonly is a full moon at its closest distance to the earth with the moon appearing larger than usual. (Photo by Hein Htet/EPA/EFE)

Merfolk gather at MerMania 2017, the world's largest gathering of amateur and professional mermaids and mermen in North Carloina, USA on January 21, 2017. (Photo by Brian Cahn/ZUMA Wire/Rex Features/Shutterstock)

Victoria's Secret angels Adriana Lima, Candice Swanepoel, Alessandra Ambrosio and Miranda Kerr arrive at the 2011 Victoria's Secret SWIM Collection Pink Carpet Event hosted by VS Angels at Club L on March 30, 2011 in Los Angeles, California. (Photo by Jerod Harris/Getty Images for Victoria's Secret)

Meghan Puhr participates in a virtual realty presentation during an Intel news conference before CES International, Wednesday, January 4, 2017, in Las Vegas. (Photo by John Locher/AP Photo)

Four-year-old Chinese boy Huang Yang plays with five-year-old beluga whale Xiao Xin at the Qingdao Ocean World on November 3, 2007 in Qingdao of Shandong Province, China. Huang Yang began swimming as a baby and fell in love with the whale after watching its performance. On the International Children's Day, June 1 this year, the Qingdao Ocean World has made the boy's dream come true when they allowed Huang Yang to swim with the beluga whale. (Photo by China Photos/Getty Images)

On August 31, 2011, a puppy was rescued from a garbage bag in Central Florida. She was afflicted by a condition dubbed “swimmer puppy syndrome”, formally, pectus excavatum. It's rare in puppies, but when it happens it causes them to lie flat on their chests with their legs perpetually splayed out. It's usually a symptom of serious neurological problems that most puppies cannot survive. Veterinarians recommended putting her to sleep... (Photo by Flyin Fur Pet Photography)