The photographs feature fish that have been specially treated to make the stained skeletal tissues visible through the skin and flesh. The technique, developed by Dr. Adam Summers, uses dyes, hydrogen peroxide, a digestive enzyme and glycerin to make the flesh seem to disappear. Photo: This image of the butterfly ray (Gymnura crebripunctata) helped scientists study the joints in its wings. (Photo by Adam Summers)

The rising sun penetrates early morning mist and begins to burn off the first frost of winter in the Cheshire countryside at dawn on 24 October, 2007, Knutsford, England. (Photo by Christopher Furlong/Getty Images)

A man dressed as Santa Claus lights a Christmas tree on City Hall square in Copenhagen, Denmark, on November 27, 2022. (Photo by Sergei Gapon/Anadolu Agency via Getty Images)

Image of the Clouds taken in August 2014 by astronauts on board the International Space Station (ISS). A year from space photographs of hurricanes, typhoons and meteorite craters show an astronauts-eye view of our planet from hundreds of miles above the earth. The illuminating images were taken by astronauts onboard the International Space Station (ISS) over the course of 2014. (Photo by NASA/SPL/Barcroft Media)

This picture taken on March 21, 2015 shows a couple kissing in front of blooming cherry blossoms in Wuhan in central China's Hubei province. The cherry blossoms, now in full bloom, attracted tens of thousands of visitors, local media reported. (Photo by AFP Photo/Stringer)

Santa Claus reacts as (L) Tami McEleney and (R) Patrice Conner whisper in his ear at the King of Prussia Mall, United States' largest retail shopping space, in King of Prussia, Pennsylvania, U.S., December 8, 2018. (Photo by Mark Makela/Reuters)

Anti-government protesters react on the grounds of the Mezhyhirya residence of Ukraine's President Viktor Yanukovich in the village Novi Petrivtsi, outside Kiev February 22, 2014. (Photo by Konstantin Chernichkin/Reuters)

Women wearing kimonos gather after attending a Coming of Age ceremony on January 8, 2018 in Yokohama, Japan. Coming of Age Day is a Japanese holiday held every January to celebrate people who have reached 20 – the official age of adulthood in Japan. Yokohama city, with almost 37,000 people turning 20 this year, is holding one of the largest events in the country. (Photo by Carl Court/Getty Images)