Transparent Frog

Scientists at Hiroshima University have succeeded in breeding see-through frogs — an innovation that could cut down on future dissections.


Transparent fishes have been around for a long time, but Professor Masayuki Sumida said the new line of frogs were the world’s first transparent four-legged animals.

Sumida, an amphibian specialist who led the university’s research team, said the transparent-skinned frogs could become widely used in scientific research because internal organs and blood vessels can be observed without dissecting the creatures.

Frogs are frequently used for research, but such projects have come in for increased criticism from animal protection groups.

Scientists have long known that certain recessive genes resulted in pale-skinned frogs, Sumida explained. The researchers were delighted to find that, under the right conditions, second generations of pairs of frogs with those recessive genes produced transparent offspring.

“It was the first time in the world, so I wanted to shout for joy,” Sumida said.

The skin of the tadpoles was nearly without pigment, and researchers could observe how the organs grew in the body as they transformed into full-grown frogs. Sumida said there was still a small amount of yellow pigment in the skin of the frogs, and he was working to breed it out.

Although the new breeding methods could lead to more humane amphibian research, Sumida said there won’t be any see-through mice or humans anytime soon. Mammalian skin is different from frog skin, so the methods will not work with mammals, he said.