Davi de Oliveira Moreira, known as "Sereio" (merman in Portuguese), poses in costume at Arpoador Rock on Ipanema Beach in Rio de Janeiro, Brazil, last May.
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American swimmer Caeleb Dressel clinched seven gold medals at the world championships on Sunday, tying a record set by Michael Phelps. Above, Dressel races in the Men's 4x100m Medley Relay Final.
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Adolph Kiefer was a teenager in 1936 when he traveled to Berlin to compete in the Olympic Games. He went on to be a Navy Lieutenant, an inventor, and a businessman. He died at the age of 98 on Friday, May 5.
China's Fu Yuanhui (left) celebrates her bronze medal win in the women's 100-meter backstroke with Canada's Kylie Masse, Hungary's Katinka Hosszu and the U.S.'s Kathleen Baker.
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Anita Alvarez and Mariya Koroleva compete in the women's duets synchronized swimming technical routine preliminary on Monday in Rio de Janeiro. Koroleva has suffered several concussions over the years.
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U.S. swimmer Katie Ledecky holds up her gold medal after winning the women's 800-meter freestyle swimming final at the Aquatics Centre in the Olympic Park during the 2012 Summer Games in London.
Yusra Mardini visits the Olympiapark Berlin on March 9. The 18-year-old Syrian refugee hopes to qualify for the Rio Olympics as a swimmer on the refugee team.
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French marathon swimmer Benoit Lecomte (left) prepares to jump into the Potomac River in Washington, D.C., in 2002. In 1998, Lecomte swam across the Atlantic Ocean.
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Daina Bouquin competes in the first U.S. Winter Swimming Championships on Saturday in Lake Memphremagog near Newport, Vt. The event drew swimmers from around the world to race in icy water that was below 32 degrees F.
Herb Swanson for NPR