September 28, 2007—For high school students everywhere, this revealing amphibian may be a cut above regular frogs.

That's because the see-through frog does not require dissection to see its organs, blood vessels, and eggs. (See a video of the frog.)

Masayuki Sumida, a professor at the Institute for Amphibian Biology at Japan's Hiroshima University, bred the frog to be a humane learning tool.

"You can watch organs of the same frog over its entire life, as you don't have to dissect it," Sumida told the news agency Agence France-Presse. The scientist announced his research last week at an academic meeting.

Dissecting animals for science has sparked controversies worldwide, even prompting some companies to create computer simulations as cruelty-free alternatives.

Researchers bred the sheer creature—a type of Japanese brown frog—for two recessive genes that make it pale.

Though not yet patented, the frog is the first four-legged, see-through animal to be bred by scientists. Some fish species are also clear.

Only 1 in 16 frogs end up see-through, and Sumida's team has not yet figured out how to pass on the transparent trait to offspring.

—Christine Dell'Amore

• More Photos in the News
• Today's Top 15 Most Popular Stories
• Free Email Newsletter: "Focus on Photography"