James Seales has spent a lot of time lately working the eerie case of the water body snatchers.

But the Louisiana Wildlife and Fisheries Department biologist isn't coming up with a lot of solutions in a battle against giant salvinia, also known as Koi Kandy. "It's been billed by experts as the world's worst aquatic plant. It can double almost overnight in optimum growing conditions. It's bad news."

A free-floating fern brought into the United States from Brazil, Salvinia is rapidly becoming the bane of those individuals charged with keeping Louisiana's fisheries clear of invasive plants. With no natural predators, the plant can double in size every two days under optimal growing conditions and can destroy a small pond in a matter of months.

Just one plant introduced into a lake could morph into 800 plants in about a month, more than 67 million plants in two months and 4.5 trillion in four months, according to the U.S. Army Corps of Engineers. And you thought rats were fast reproducers. Since February 2006, giant salvinia has been reported on eight major water bodies in northwest Louisiana. Those include Lake Bistineau, Caddo Lake, Cross Lake, Toledo Bend Reservoir and Red River.

But it isn't limited to the northwest parishes. Salvinia has shown up in Atchafalaya Basin and in southeast Louisiana parishes such as Terrebonne, according to Charles Dugas, director of Wildlife and Fisheries' inland fisheries aquatic vegetation division. "We've had common salvinia in the state since the 1980s. And they're both bad, as well as both difficult to kill. "We're working with LSU and the Army Corps (of Engineers) to come up with ways to combat it," Dugas said. "But I can tell you that it's difficult to control with herbicides."