for National Geographic News
This is the second installment in a series on the Megafishes Project. Join National Geographic News on the trail with project scientists as they track down the world's largest freshwater fishes.
If the world's largest freshwater fish still exists, Wei Qiwei will be there to save it.
"I believe it's out there," said Wei, as he scanned the murky Yangtze River from his sleek, 63-foot (19-meter) rescue vessel.
Wei is one of China's foremost experts on the Chinese paddlefish, a leviathan that reportedly can grow 23 feet (7 meters) long and weigh half a ton.
But the odds of finding even a single one of the aquatic giants may be steadily diminishing.
No adult Chinese paddlefish have been caught in the Yangtze River by fishers since 2003. Even more worrisome, no young paddlefish have been seen since 1995.
"When you don't see juveniles, we think maybe there's no spawning," said Wei, who heads a research laboratory at the Yangtze River Fisheries Research Institute in Jingzhou (see China map).
He and other experts fear that even if individual paddlefish are found in the Yangtze, the species itself, if unable to reproduce, could be on an irreversible path to extinction.
The Chinese paddlefish is also known as the elephant fish, because its long snout resembles an elephant's trunk.
The predators feed on other fish, as well as small amounts of crab and crayfish.
Prized for their rich, plentiful meat, the giant animals are said to have been commonly offered as gifts to the Chinese emperor during imperial times.
SOURCES AND RELATED WEB SITES