- 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 of head: The lines are indicating distances: eye-preopercle corner, eye-upper gill cleft; the lines are about equal in length.
- Close-up of mouth: Notice the obtuse angle of the lips with a nipple at the tip; there are no barbels.
- Close-up of head: Notice that the tip of the lower lip is just barely in advance of the nostrils, and there is no "notch" anterior to the nostrils.
- The back is steeply arched, body depth is 38-45% of SL, head length is 24-27% of SL, the sides are silvery.
- Close-up dorsal fin: Notice that the longest dorsal ray is longer than the dorsal fin base; there is no spine and 23-27 rays.
- Close-up anal fin: Notice that the anal fin is unpigmented; there is no spine and 8-9 rays.
- Close-up pelvic fin: Notice that the pelvic fin is clear.
- Close-up head region of a breeder: Notice the numerous tubercles on head and scales.
- Close-up nape and back of a breeder: Notice the numerous tubercles on the head and the back.
- Close-up head of a breeder: Notice the numerous tubercles on the head.
- Head-on view of a breeder: Notice the numerous tubercles on the head.
- Side view of a yearling: Juveniles are less deep-bodied, and they have larger eyes relative to adults.
- Underside of head of a yearling: Notice the obtuse angle of the lips with a nipple at the tip; there are no barbels.
- Alternate side view.
Mouth and snout: Inferior, no teeth on jaws. No barbels. Body patterning, color, and scales: Solid color. Body overall silvery, grading from olive-brown on back to white or cream on the belly. Fins usually clear. 33-35 cycloid lateral line scales. Body shape and size: Body lateralle compressed and deep; oval in cross section. Typically 300-400 mm (12-16 in) TL; maximum in Wisconsin about 500 mm (20 in).
Tail, dorsal and other fins: Forked tail. Single dorsal with no spines and 23-27 rays; first few rays elongated. Pelvic fins abdominal. Adipose fin absent. Anal fin with 8-9 rays.
The highfin carpsucker can be distinguished by its lack of a serrated spine at the front of the dorsal and anal fins, by its inferior mouth, its number of anal rays (7-9), number of dorsal rays (22-30 vs 15-19), the number of lateral line scales (33-40), by its lack of barbels, by the ratio of the distance from the eye to the ventro-posterior angle of the pre-opercle to the distance from the eye to dorso-posterior edge of the gill opening, which is about one, the presence of a fontanelle (hole) in the roof of the skull between the eyes in the carpsuckers but not the buffalos, a paper-thin pharyngeal arch, linear in cross-section, and a helical (spiral) pattern of coiling of the intestine. See also similar species information.
Males with numerous minute tubercles on head and pectoral and pelvic rays.
Somewhat less deep-bodied with a less sharply arched back and a relatively larger eye.
Quillback X Highfin carpsucker; River carpsucker X Highfin carpsucker, plausible, but unconfirmed from Wisconsin.
|Carpsucker, Highfin||Form an abtuse angle (>120°); small knob or nipple at tip; tip about equal with nostrils in side view|
|Carpsucker, River||Form an abtuse angle (>120°); small knob or nipple at tip; tip about equal with nostrils in side view|
|Quillback||Form an abtuse angle (<90°); no knob at tip; tip clearly forward of nostrils in side view|
Longest Dorsal Ray
|Carpsucker, Highfin||Length of ray usually more than the length of the dorsal fin base (but ray sometimes broken)|
|Carpsucker, River||Length of ray when depressed about 50-70% the length of the dorsal fin base|
|Quillback||Length of ray variable (and sometimes broken), ranging from about 70-110% the length of the dorsal fin base|
|Carpsucker, Highfin||Steeply arched back; BD 38-45% of SL; HL 24-27% of SL; short snout, seldom with "notch" anterior to nostrils in lateral view|
|Carpsucker, River||Arched back, body depth (BD) 32-43% of standard length (SL); head length (HL) 24-29% of SL, short snout, seldom with "notch" anterior to nostrils in lateral view|
|Quillback||Rounded back, BD 32-38% of SL; HL 26-32% of SL; snout relatively long, usually with "notch" anterior to nostrils in lateral view|
|Carpsucker, River||Very similar|