The Northern Pikeminnow has a head that is somewhat flattened between the eyes.
A long snout and a large mouth - you can usually insert 2 to 3 fingers fully into an 11-inch Northern Pikeminnow’s mouth.
One of the best ways to determine the difference between a Peamouth and a Northern Pikeminnow is to compare where the corner of the mouth ends. On a Northern Pikeminnow the corner of the mouth comes back to the eye, while on the Peamouth, the corner of the mouth is well before the eye.
The barbels at the corner of the Peamouth’s mouth are missing on the Northern Pikeminnow, as are the dark bars on the side.
Northern Pikeminnow from the Columbia River are generally a bright silvery color, while those from tributaries will usually be darker and more colored.
Peamouth are the species most commonly confused with the Northern Pikeminnow. Body shape is similar to the Northern Pikeminnow, but usually slimmer.
The Peamouth’s head is more rounded than a Northern Pikeminnow.
The species two mouths are quite different. The Peamouth’s round mouth is much smaller than the Northern Pikeminnow's. Generally you can only fit the tip of a finger in the Peamouth’s mouth.
There is red coloring around the lips, and a small barbel at each corner of the mouth.
Also look for two dark lateral bars on the side, which turn reddish during spawning time.
Peamouth are a native fish, they do not prey on or compete heavily with salmonid smolts. Peamouth should not be wantonly killed and discarded as trash fish.