January 30, 2006—It may be tiny, but this fish has sparked a debate that's big—though nowhere near as ugly.

A U.S. scientist says this male anglerfish found in the Philippines is the smallest fish in the world.

Ted Pietsch, a fisheries professor at the University of Washington in Seattle, discovered the fish in the collection of the Scripps Institution of Oceanography in San Diego, California. He first announced his find last May.

A mere 0.24 inch (6.2 millimeters) long, the fish known as Photocorynus spiniceps may take the prize as the world's smallest catch. But it has some wee competition.

Last week an international team of researchers announced that they, too, had discovered Earth's littlest fish. Their find, a member of the carp family found in the peat swamps of Indonesia, is 0.31 inch (7.9 millimeters) long and so slim that it's transparent.

What's more, scientists at the Australian Museum in Sydney in 2004 unveiled a tiny fish found in the Great Barrier Reef that measures from 0.28 to 0.31 inch (7 to 8 millimeters) in length.

In the end, the real winner in this fish tale depends on how you size things up, Pietsch says.

"The debate centers on how you define 'smallest,'" Pietsch writes by email. "The [Australian Museum] folks want to use volume as the measure, but [other scientists] use length.

"If length is an acceptable criterion, then surely my Photocorynus is the smallest known sexually mature vertebrate by a full 1.7 millimeters [0.06 inch]."

Pietsch re-released his study late last week as a kindly reminder to his colleagues, who have been taking part in this "friendly rivalry" for years, he says.

"The other researchers … know my work and I theirs," he says. "But somehow in the latest story that broke early last week, my publication on Photocorynus was left out. So I thought I'd jump into the fray."

—Blake de Pastino

• See More Photos in the News
• See Today's Top News Stories
• Get Our Free Photo Newsletter