A LITTLE EXTRA HOP: RESEARCHERS MYSTIFIED BY FROGS WITH FIVE LEGS

JEFFERSON CITY -- A mystery that came to light when a youngster found a five-legged frog in a Columbia pond remains unsolved. But officials with the Missouri Department of Conservation say they are getting more reports and hope to find enough evidence to unlock the secrets of what is causing deformities in Missouri amphibians.

Brian Dampier, a seventh-grader at Gentry Middle School in Columbia found a green frog with an extra hind leg in a pond near his school last October. His science teacher, Mike Bielski, had read that deformed frogs were appearing by the hundreds in other scattered locations in the upper Midwest, so he called the Missouri Department of Conservation headquarters in Jefferson City and talked with Herpetologist Tom Johnson. Johnson visited the Columbia site, but wasn't able to find any other abnormal frogs. Lacking more than one deformed frog, Johnson concluded that it would be fruitless to try to discover the nature of the problem, let alone the source at the site.

"Amphibians are just naturally more prone to this kind of thing," said Johnson. "Frogs' and other amphibians' tissues are more changeable than those of birds and mammals. Some can even regenerate lost limbs. Reports of frogs with extra legs aren't unusual, even going back a hundred years. What is unusual is the occurrence of a lot of deformed specimens in one place.

That's what has gotten the attention of biologists in some of the upper Midwestern states."

Still, Johnson said he wasn't inclined to dismiss Dampier's report. He contacted water-quality workers at the MDC research office in Columbia and with the Missouri Department of Natural Resources and assembled a sort of ad hoc deformed frog task force that could respond quickly to study any significant outbreak of deformed frogs that develop. He also publicized Dampier's find through a media news release and asked anyone who found a deformed amphibian to notify him.

That brought immediate results. So far, he has received 17 other reports of deformed amphibians, mostly frogs. The reports came from widely scattered locations around the state -- Holt, Clay, Adair, Schuyler, Marion, Boone, Osage, Lincoln, St. Charles, Franklin, Washington, Laclede, Christian, Greene, Benton and Barry counties. Most (12) were reports of animals found in 1996, but five came from the past -- two in 1995 and one each in 1992, 1991 and 1964.

Fifteen of the reports -- like Dampier's -- involved frogs with too many or too few limbs. Three were missing an eye. The most commonly affected species were bullfrogs and green frogs, possibly because these two species are large and attract the attention of people who want to eat their legs, but two leopard frogs, a toad and a tree frog also turned up.

While he is gratified that 17 people responded to his request for sightings of deformed amphibians, Johnson says there is little he can do with the information he has so far. What he has done is to send specimens -- where they were available -- to a researcher who is exploring the possibility that the deformities are caused by a parasitic worm known as a "fluke."

"Investigations of big outbreaks of deformed frogs in California have shown that parasites were the cause," said Johnson. "In other cases chemical pollution is a possible explanation."

Johnson is wondering what will be found next summer in Missouri and he is considering every possible cause.

"A few people have written me, obviously very alarmed and convinced that pollution is causing this," said Johnson. "For the most part, it has been youngsters who are very interested in protecting our environment from chemicals. If this were the result of chemicals, I would expect to see more than just one or two frogs in a given area with the problem. The fact that isn't happening should be very reassuring to those who are worried about it."

Johnson said he still is interested in reports of amphibians with deformities. He says that if he does learn of a place with multiple sightings of abnormal frogs, he and a team of experts will respond quickly.

"We don't take this lightly," he says. "I'm afraid that when we said that a 'fluke' might be responsible, some people may have thought we were dismissing this as an unimportant, accidental kind of thing. That's not the case at all. These parasites known as flukes definitely can cause deformities like an extra leg or missing leg. But we don't have our minds made up about the cause or causes. We want to know about any future sightings, and we will investigate them very carefully."