I was wondering if anybody has kept these guys. They are awesome to view in the wild, I saw roughly five of them corral some young brown trout in a ball and begin snapping them out as they struck. How big do they get, what do they eat besides fish, and compatibility issues?

Fishbase.org is your one-stop-shop for that kind of basic info; here's the northern pikeminnow page: http://www.fishbase....ry.php?id=2940. I haven't kept or even seen any of those guys, but they seem like they'd be fun captives.

There is a bounty on them in Washington I think. They have to be 9" for money, some people have made $40,000+ just fishing for them. They eat tons of Salmon & Trout, & do extreamly well in the damed rivers. Its interesting that only the Northen Pikeminnow (Squawfish) is doing so well, the other three species are not so hated. The Colorado Pikeminnow is endangered unfortunitly because it used to get over 6' long and over 80 lbs.
The Sacramento Pikeminnow can get 4 feet long & the Umpqua Pikeminnow gets 2 feet long.
So bigest to smallest:
Colorado Pikeminnow
Sacramento Pikeminnow
Northern Pikeminnow
Umpqua Pikeminnow
Last time I was at the Shedd Aquariumin Chicago they had some Colorado Pikeminnow in one of there big tanks.