White Sucker (Catostomus commersonii) - Native

48 cm white sucker.

A typical 19-inch adult white sucker.

Identification. Streamlined, cylindrical body. Usually no marks on body or fins, except for occasional faint blotching. Young usually have more conspicuous dark blotches. Lower lip has numerous small bumps (papillae). Snout extends only slightly ahead of mouth. Posterior end of mouth does not or only barely reaches nostrils. Complete lateral line. Diamond-shaped, moderate-size scales (55-80 lateral line scales). Dorsal rays 11-12. Usually brown, sometimes greenish or grayish on back fading to silvery, greenish or bronze on sides, and whitish on the belly. Males develop dark lateral stripe during spawning.

Ventral view of white sucker mouth.

Close-up of papillae on the downturned mouth of a white sucker.

Size. Commonly 6 to 18 inches. State survey max. size 23 inches. Max. reported size 28 inches.

Distribution. Widespread over most of North America east of the Rockies. Occur in almost all but the smallest Connecticut streams where they are typically common to abundant. Also found in most lakes that have significant tributary streams suitable for spawning.

White sucker distribution map.

All maps created in 2009. See CT DEEP Fish Community Data for updated distributions.

Habits. Can be found in a wide range of habitats. Are most abundant during early spring (March-early May) spawning runs up tributary streams. These runs can be very impressive and easily observed, with hundreds of individuals crammed into pools of small streams. White suckers can sometimes be caught by angling with bait on the bottom. Juveniles can be caught with a small-mesh dip net or seine.

Comments. The white sucker is by far the most abundant native fish of its size in Connecticut and makes up the majority of the fish biomass in many streams. For this reason, it is also arguably our most important fish species. One of the best places to observe their spring migration run is at the Leesville Dam and Fishway on the Salmon River in East Haddam, where they congregate by the thousands.


Text and images adapted from Jacobs, R. P., O'Donnell, E. B., and Connecticut DEEP. (2009). A Pictorial Guide to Freshwater Fishes of Connecticut. Hartford, CT. Available for purchase at the DEEP Store.