white sucker

white sucker (Catostomus commersonii) Photo © Engbretson Underwater Photography

The white sucker may attain a length of 10 to 16 inches. There is a notch in its lower lip, and the lower lip is about twice as thick as the upper lip. Both lips are covered with small bumps (papillae). The back and sides are green-brown to black with a silver luster. The scales are often outlined with dark pigment. The dorsal and tail fins are clear or dusky while the lower fins are white with orange or yellow. The breeding male is gold on his back and has a red or pink stripe along the sides. Small projections (tubercles) are present on the breeding male’s head, body and fins.

The white sucker may be found statewide in Illinois, including Lake Michigan. This fish lives in creeks, small rivers and lakes. It swims in schools near the bottom. Spawning occurs in early spring with many fish at one site. The actions of the adults clean the gravel bottom of silt and bury the eggs in the gravel. Eggs hatch in about 18 to 20 days. The white sucker feeds along the bottom, eating mainly insects.

Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Cypriniformes
Family: Catostomidae