| 1a |
Elongated dorsal fin |
go to 2 |
| 1b |
Single short dorsal fin |
go to 4 |
| 2a |
Small head and falcate (long) pectoral fins |
Cycleptus elongatus (Blue Sucker) |
| 2b |
Normal sized head and pointed snout |
go to 3 |
| 3a |
Mouth is inferior and subopercle is triangular |
Carpiodes carpio (River Carpsucker) |
| 3b |
Snout protrudes over mouth, mouth subterminal, and rounded subopercle |
Ictiobus bubalus (Smallmouth Buffalo) |
| 4a |
Scale bases darker than rest of scale and mouth is inferior |
Minytrema melanops (Spotted Sucker) |
| 4b |
Scale base same color as scale |
go to 5 |
| 5a |
Complete midlateral stripe, no lateral line, mouth subterminal |
Erimyzon sucetta (Lake Chubsucker) |
| 5b |
partial midlateral stripe |
go to 6 |
| 6a |
partial midlateral stripe, incomplete or absent lateral line, 2 swim bladders |
Erimyzon oblongus (Creek Chubsucker) |
| 6b |
Complete lateral line and 3 swim bladders |
go to 7 |
| 7a |
Black streak on caudal fin and mouth subterminal |
Moxostoma poecilurum (Blacktail Redhorse) |
| 7b |
No black streak present on caudal fin |
go to 8 |
| 8a |
Pectoral fin as long as head, Small inferior mouth, and thick lips |
Moxostomal congestum (Gray Redhorse) |
| 8b |
Mouth subterminal and long intestine (2-3 coils) |
Moxostoma erythrurum (Golden Redhorse) |