If you peer into a clear creek and see a long fish holding just above the gravel, mouth pointed straight down, you are watching a White Sucker (Catostomus commersonii). It patrols the bottom like a slow, steady vacuum.
What it looks like
Adults commonly run 30 to 50cm long with a rounded, torpedo-shaped body. The back is olive to gray-brown, fading to a pale, almost white belly. The signature feature is the mouth, set on the underside of the snout with thick, rubbery lips built for suction. Young suckers show dark blotches along the side that fade as they grow. In spring the males often develop a rosy stripe down the flank.
When and where
- Season: Present year round, easiest to see during the spring spawning run.
- Habitat: Creek and river bottoms, lake shallows, and pools with gravel or sand.
- Best time: Spring, when they crowd into shallow riffles to spawn.
The spring gathering
Each spring, White Suckers leave deeper water and swim up into shallow, stony riffles to spawn, sometimes in large groups you can watch from the bank. Females release thousands of eggs that settle into the gravel, and the adults drift back downstream afterward. Because they need clean, well-oxygenated water to breed, a healthy sucker run is a good sign that the creek itself is in good shape.
Spot one this weekend
White Suckers are Common in creeks and rivers across the region. Look into clear, shallow water over gravel for a long fish nosing along the bottom. If you see it hovering with its mouth aimed straight down, you have found a sucker.