For some anglers, carp become an obsession.(Knight Ridder Newspapers)

Byline: Chris Niskanen

COON RAPIDS, Minn. _ Carp fisherman Bob Siegel dug into a bag containing tiny bottles of liquid to search for his secret weapon.

He reached past a bottle containing a mysterious concoction from South Africa. He dug past bottles of anise and banana flavors and past a brown vial labeled "strawberry." His hand settled on a perfume-sized bottle recently shipped from Chicago, the one with an eyedropper and a tiny label with cryptic lettering.

In a low voice, the 3M engineer revealed its name.

"It's called 'Obsession for Carp,' '' Siegel said. "It looks like soy sauce, it smells like soy sauce, but I'm sure there's some secret ingredient."

Siegel drizzled some of the liquid on a ball of white bread and sent the bait whizzing into the Mississippi River above the Coon Rapids dam. Before long, he was fighting a carp, a species he calls the "biggest and hardest fighting fish around."

Carp might be the Rodney Dangerfields of the fish world, but Siegel is obsessed with the fish, and so are a few of his friends.