The snakehead fish, best known lately as a threat to U.S. waters, may finally be doing some good. A German scientist asserts that fossils of relatives of the much-feared invader can shed light on major climatic changes of the distant past.
The air-breathing freshwater fish can crawl on its strong pectoral fins over land between lakes and rivers, taking over ecosystems that it moves into. The snakeheads now invading the United States aren't typical. Most of the world's 29 snakehead species in the family Channidae thrive only in warm, wet conditions.
The fish's need for humid air makes the snakehead an indictor of climate, says Madelaine Böhme of the University of Munich in the May Geology. Scientists can deduce that wherever they find snakehead fossils, the climate must have been humid at the time the fish lived there, she says.
"It's a novel approach," says James Kennett, a paleoclimatologist of the University of California, Santa Barbara.