- Side view adult.
- Side view adult.
- Side view adult.
- Top view adult.
- Bottom view adult.
- Head-on view adult.
- Close-up flank.
- Close-up head.
- Close-up mouth and snout.
- Close-up tail.
- Close-up dorsal fin.
- Close-up anal fin.
- Close-up pectoral fin.
- Close-up pelvic fin.
- The sides show a solid to faintly blotched color and 55-85 lateral line scales.
- Close-up dorsal fin: There are 10-13 dorsal rays, the margin is slightly concave.
- Close-up head: The snout barely extends past the upper lip.
- Close-up mouth/snout: The fleshy and papillose lower lips form an acute angle.
- Close-up flank: The flanks show a solid to faintly blotched/mottled color.
- Side view of a breeder: The flanks in breeders show a broad, diffuse lateral stripe and tubercles on the anal and tail fins.
- Close-up head of a breeder: Breeders develop fine tubercles on top of their heads.
- Anterior dorsal view of a breeder: Breeders develop fine tubercles on nape and dorsal surface.
- Side view of a breeding male: The flanks in breeders shows a dark broad lateral stripe.
- Close-up caudal region of a breeder: Breeders develop large tubercles on their anal and tail fins.
- Close-up dorsal fin of a breeder: Breeders develop fine tubercles on their dorsal rays.
- Side view of a young-of-year: Juveniles are similar to adults, but lack blotches on their sides.
- Comparison longnose sucker and white sucker: The longnose sucker has a longer snout and smaller scales than the white sucker.
- Alternative side view of an adult.
Mouth and snout: Inferior, no teeth on jaws. No barbels. Body patterning, color, and scales: Solid color or mottled and irregular blotches (but see also Breeding adults). Body usually olive, tan, gray, or brown, sometimes with irregular darker mottling (see also Juveniles). Belly whitish. Tail and dorsal fin slate colored; other fins usually clear or whitish with limited dark pigment. 55-85 (usually 60-70) cycloid lateral line scales. Body shape and size: Body fusiform or slightly dorsal-ventrally flattened and elongate; approximately round in cross section (flattened on ventral surface). Typically 300-450 mm (12-18 in) TL; maximum about 600 mm (24 in).
Tail, dorsal and other fins: Forked tail. Single dorsal with no spines and 10-13 rays. Pelvic fins abdominal. Adipose fin absent. Anal fin with 7 rays.
The white sucker is unique in having the combination of 55-85 lateral line scales and 10-13 dorsal rays. It can also be distinguished by its number of dorsal rays (10-13), lateral line scales (55-85), and its lower lip that is broad and fleshy throughout. See also similar species information.
Males with tubercles on head, scales, anal, and caudal fin (photos). Males also with black or crimson broad lateral stripe (photos).
Similar to adults, but often with three large irregular blotches on flanks (photos).
None confirmed from Wisconsin.
|Redhorse, Black||12-14 rays, margin concave or falcate, rarely straight|
|Redhorse, Golden||10-15 rays, usually 13, margin concave or falcate, rarely straight|
|Redhorse, Greater||11-15 rays, usually 13-14, margin slightly concave to slightly convex|
|Redhorse, River||13-15 rays, margin straight or slightly concave|
|Redhorse, Shorthead||11-15 rays, usually 12-14, margin falcate|
|Redhorse, Silver||14-17 rays, usually 15, margin usually straight or slightly convex|
|Sucker, Blue||28-33 rays, anterior rays elongated|
|Sucker, Longnose||9-11 rays, marging straight to slightly concave|
|Sucker, Northern Hog||9-12 rays, usually 11-12, margin falcate|
|Sucker, Spotted||11-12 rays, margin straight to falcate|
|Sucker, White||10-13 rays, margin slightly concave to slightly convex|
|Redhorse, Black||Obtuse angle or straight margin, plicate|
|Redhorse, Golden||Obtuse angle, plicate|
|Redhorse, Greater||Obtuse angle, plicate|
|Redhorse, River||Obtuse angle or straight margin, plicate|
|Redhorse, Shorthead||Straight margin, plicate with a few papillae|
|Redhorse, Silver||Acute or right angle, papillose|
|Sucker, Blue||Acute angle, papillose|
|Sucker, Longnose||Acute angle, papillose|
|Sucker, Northern Hog||Acute angle, papillose|
|Sucker, Spotted||Obtuse angle, relatively thin, plicate|
|Sucker, White||Acute angle, papillose|
|Redhorse, Black||Solid color|
|Redhorse, Golden||Solid color|
|Redhorse, Greater||Solid color or with faint spots at anterior base scales in some fish|
|Redhorse, River||Solid color or with faint spots at anterior base scales in some fish|
|Redhorse, Shorthead||Solid color or with faint spots at anterior base scales in some fish|
|Redhorse, Silver||Solid color|
|Sucker, Blue||Solid color, darkly pigmented|
|Sucker, Longnose||Solid color or faint blotches, breeders with lateral stripe|
|Sucker, Northern Hog||Dark mottling and large dark irregular blotches|
|Sucker, Spotted||Dark spots at anterior base of scales; lateral stripes in some breeders|
|Sucker, White||Solid color or faint blotches, breeders with lateral stripe|
Lateral Line Scales
|Redhorse, Black||43-51, usually 44-47, all pored|
|Redhorse, Golden||37-45, usually 40-42, all pored|
|Redhorse, Greater||41-45, usually 42-44, all pored|
|Redhorse, River||41-46, usually 42-44, all pored|
|Redhorse, Shorthead||39-46, usually 42-44, all pored|
|Redhorse, Silver||38-46, usually 41-42, all pored|
|Sucker, Blue||53-58, all pored|
|Sucker, Longnose||91-115, usually >95, all pored|
|Sucker, Northern Hog||46-54, usually 47-51, all pored|
|Sucker, Spotted||42-46, 0-38 pored|
|Sucker, White||55-85, usually 60-70, all pored|
|Redhorse, Black||Pelvic rays 8-11 but almost always one or both with 10; caudal peduncle depth >59% of caudal peduncle length; tail slate-colored in life|
|Redhorse, Golden||Pelvic rays 9; caudal peduncle depth usually >63% of caudal peduncle length; tail slate-colored in life|
|Redhorse, Greater||Head rounded with a rounded snout, not overhanging lips ventrally; tail orange or red in life; scales around caudal peduncle 15-16|
|Redhorse, River||Head rounded and bulky with a blunt or slightly rounded snout, overhanging lips ventrally in adults; tail orange or red in life; scales around caudal peduncle 12-13|
|Redhorse, Shorthead||Head tapered to a pointed or slightly blunt snout, not overhanging lips ventrally; tail orange or red in life; scales around caudal peduncle 12-13|
|Redhorse, Silver||Tail slate-colored in life|
|Sucker, Blue||Darkly pigmented fins|
|Sucker, Longnose||Snout distinctly extends past upper lip|
|Sucker, Northern Hog||Top of head with concavity between eyes; other species have this area flat or convex|
|Sucker, Spotted||Spotes lined up in horizontal rows; limited to area above anal fin in small juveniles|
|Sucker, White||Snout barely extends past upper lip|
|Redhorse, Black||Moderately similar|
|Redhorse, Golden||Moderately similar|
|Redhorse, Greater||Moderately similar|
|Redhorse, River||Moderately similar|
|Redhorse, Shorthead||Moderately similar|
|Redhorse, Silver||Moderately similar|
|Sucker, Blue||Moderately similar|
|Sucker, Longnose||Very similar|
|Sucker, Northern Hog||Moderately similar|
|Sucker, Spotted||Moderately similar|