River Carpsucker
  • 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 lines are indicating distances: eye-preopercle corner, eye-upper gill cleft; the lines are about equal in length.
  • Close-up head: Notice that the tip of the lower lip is just slightly anterior to the nostrils, there is no "notch" anterior to the nostrils.
  • Close-up dorsal fin: Notice that the longest dorsal ray is about 1/2 length of the dorsal fin base; there is no spine and 23-27 rays.
  • The back is arched, the body depth is 32-43% of SL, the head length is 24-29% of SL; the sides are silvery.
  • Close-up anal fin: The anal fin is unpigmented; ther is no spine and 7-8 rays.
  • Close-up pelvic fin: Notice that the pelvic fin is clear.
  • Close-up mouth: The lips form an obtuse angle and have a nipple at the tip; there are no barbels.
  • Close-up head region of a breeder: Notice the numerous tubercles on head and scales.
  • Close-up head of a breeder: Notice the numerous tubercles on the head.
  • Close-up pectoral fin: Notice the tubercles on the anterior rays.
  • Close-up underside of head of a breeder: Notice the numerous tubercles on the head.
  • Side view of a young-of-year: Notice the less highly arched back, the eyes are larger relative to adults.
  • Close-up mouth of a juvenile: The lips form an obtuse; there is a nipple at the tip of the lower lip and there are no barbels.
  • Comparison of mouth of river carpsucker (left) and quillback (right): Quillback lips form an acute angle without nipple; river carpsucker lips form an obtuse angle with a nipple.
  • Alternative side view of an adult.
  • Alternate side view of an adult.
  • Side view of a river carpsucker X quillback hybrid: The hybrid has a quillback body form, but a river carpsucker mouth.
  • Side view of a river carpsucker X quillback hybrid: The hybrid has a quillback body form, but a river carpsucker mouth.
  • Side view of a river carpsucker X quillback hybrid: The hybrid has a quillback body form, but a river carpsucker mouth.
  • Side view of a river carpsucker X quillback hybrid: The hybrid has a quillback body form, but a river carpsucker mouth.
DescriptionSimilar Species
Family
Suckers (Catostomidae)
Body
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. 34-36 cycloid lateral line scales. Body shape and size: Body laterally compressed and deep; oval in cross section. Typically 350-450 mm (14-18 in) TL; maximum in Wisconsin about 530 mm (21 in).
Fins
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 7-8 rays.
Distinguishing Characteristics
The river carpsucker can be distinguished by its lack of a serrated spine at the front of the dorsal and anal fins, its number of anal rays (7-9), its inferior mouth, its lack of barbels, 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, a paper-thin pharyngeal arch, linear in cross-section, and a helical (spiral) pattern of coiling of the intestine. See also similar species information.
Breeding Adults
Males with numerous minute tubercles on head and pectoral and pelvic rays (photos).
Juveniles
Somewhat less deep-bodied with a less sharply arched back and a relatively larger eye (photos).
Hybrids
River carpsucker X quillback (photos); river carpsucker X highfin carpsucker reported from Ohio and plausible from Wisconsin, but no confirmed specimens.
Compare Similar Species
Lower Lips
Carpsucker, HighfinForm an abtuse angle (>120°); small knob or nipple at tip; tip about equal with nostrils in side view
Carpsucker, RiverForm an abtuse angle (>120°); small knob or nipple at tip; tip about equal with nostrils in side view
QuillbackForm an abtuse angle (<90°); no knob at tip; tip clearly forward of nostrils in side view
Longest Dorsal Ray
Carpsucker, HighfinLength of ray usually more than the length of the dorsal fin base (but ray sometimes broken)
Carpsucker, RiverLength of ray when depressed about 50-70% the length of the dorsal fin base
QuillbackLength of ray variable (and sometimes broken), ranging from about 70-110% the length of the dorsal fin base
Body Profile
Carpsucker, HighfinSteeply arched back; BD 38-45% of SL; HL 24-27% of SL; short snout, seldom with "notch" anterior to nostrils in lateral view
Carpsucker, RiverArched 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
QuillbackRounded back, BD 32-38% of SL; HL 26-32% of SL; snout relatively long, usually with "notch" anterior to nostrils in lateral view
Similarity Index
Carpsucker, HighfinVery similar
Carpsucker, RiverN/A
QuillbackVery similar
Login