Longnose Sucker

Catostomus catostomus

The longnose sucker (Catostomus catostomus) is a streamlined freshwater fish reaching up to 64 cm. It has an elongated body with a distinctive long snout and a ventral, fleshy-lipped mouth adapted for bottom feeding. Coloring is dark olive to brown above and pale below, with males developing a vivid red lateral stripe during spawning season. Found across northern North America from the northern United States to Alaska and northern Canada, and in parts of Siberia, it inhabits clear, cold lakes and rivers at depths of 0 to 30 meters. This species feeds by sucking up algae, invertebrates, and detritus from rocky and gravel substrates. Its abundance and large size make it a commonly encountered fish during freshwater dives in northern lakes and rivers, where groups can be observed methodically working over rocky bottoms.