- 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.
- Close-up head: The mouth is inferior.
- Close-up mouth/snout: The lips are fleshy and papilose.
- The body shape is elongated and fusiform, the color is bluish; there are 53-58 lateral line scales and 28-33 dorsal rays.
- Close-up dorsal fin: There are 28-33 dorsal rays with anterior rays being elongated.
- Breeders develop numerous turbercles on their fins and bodies.
- Breeders develop numerous turbercles and a dark color on their bodies; specimen held by Kyle Piller.
- Breeders develop numerous turbercles on tail and scales.
- Breeders develop numerous turbercles on their heads.
- Juveniles are similar to adults, but lower lobe of caudal fin is darker.
- Side view of the largest confirmed specimen from Wisconsin (weight 7.5 kg).
Mouth and snout: Inferior, no teeth on jaws. No barbels. Body patterning, color, and scales: Solid colors. Body usually dark gray or blue-black, but sometimes a dark reddish brown or a lighter blue-gray, with cream on the belly. Fins darkly pigmented. 53-58 cycloid lateral line scales. Body shape and size: Body fusiform and elongate; oval in cross section. Typically 600-750 mm (24-30 in) TL; maximum in Wisconsin about 900 mm (36 in).
Tail, dorsal and other fins: Forked tail. Single dorsal with no spines and 28-33; anterior rays somewhat elongated. Pelvic fins abdominal. Adipose fin absent. Anal fin with 7-8 (usually 7) rays.
The blue sucker is unique in having more than 25 dorsal rays, the anterior ones elongated, more than 50 lateral line scales, and an elongated fusiform body. See also similar species information.
Males with numerous small tubercles over head, scales, and fins, often very dark colored.
Very small young of the year have the lower caudal lobe darkly pigmented and the upper lobe clear. Larger juveniles are similar to adults.
|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, Longnose||Moderately similar|
|Sucker, Northern Hog||Moderately similar|
|Sucker, Spotted||Moderately similar|
|Sucker, White||Moderately similar|