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)

Grace Chon has put together a series of portraits featuring her 10-month-old son and her rescue dog. In each picture, the dog and baby are wearing matching apparel with party hats, baseball caps and sunglasses, adding fun elements to these adorable portraits.

Two brown bear cubs born at Whipsnade Zoo. (Photo by Evening Standard/Getty Images). 1970

Scandinavia, always ahead of the bike infrastructure curve, has something else to share: a self-service cycle lift for hilly roads.

A photographer with a hidden camera took 2,500 photos before this elusive badger was ready for his close-up in September 2020. (Photo by Andy Swinden/BNPS)

A man poses for a picture in front of Christmas lights decoration at the Francisco Morazan square in San Salvador, El Salvador, December 22, 2020. (Photo by Jose Cabezas/Reuters)

An Iranian girl walks at the Tochal ski resort, in north of Tehran, Iran on December 12, 2019. (Photo by Nazanin Tabatabaee/WANA via Reuters)

A woman carries an inflatable float with the sahpe of a portion of pizza in a Barcelona, on July 18, 2020. Four million residents of Barcelona have been urged to stay at home as virus cases rise, while EU leaders were set to meet again in Brussels, seeking to rescue Europe's economy from the ravages of the pandemic. (Photo by Josep Lago/AFP Photo)