It's a toothy giant that can grow longer than a horse and heavier than a refrigerator, a fearsome-looking prehistoric fish that plied US waters from the Gulf of Mexico to Illinois until it disappeared from many states a half-century ago. Persecuted by anglers and deprived of places to spawn, the alligator gar—with a head that resembles an alligator and two rows of needlelike teeth—survived primarily in Southern states in the tributaries of the Mississippi River and Gulf of Mexico after being declared extinct in several states farther north. To many, it was a freak, a "trash fish" that threatened sport fish, something to be exterminated. But now, reports the AP, the alligator gar is being seen as a valuable fish in its own right.
Specifically, it's being seen as a potential weapon against a more threatening intruder: the invasive Asian carp. "What else is going to be able to eat those monster carp?" says an alligator gar expert at Nicholls State University in Louisiana. "We haven't found any other way to control them." Gar have shown a taste for the carp, and they're now being restocked in lakes, rivers, and backwaters—sometimes in secret locations—in states from Illinois to Tennessee. Still, the extent to which gar can control carp isn't well understood, and some people are skeptical. "I don't think alligator gar are going to be the silver bullet that is going to control carp by any stretch of the imagination," an Illinois biologist says. (Read more fish stories.)