Blue Catfish
  • Side view adult.
  • Side view adult.
  • Side view adult; the opercle and the caudal peduncle region were damaged during capture by the gill net.
  • Top view adult; the opercle and the caudal peduncle region were damaged during capture by the gill net.
  • Bottom view adult.
  • Head-on view adult.
  • Close-up flank.
  • Close-up head; the opercle region was damaged during capture by the gill net.
  • Close-up mouth and snout.
  • Close-up tail.
  • Close-up dorsal fin.
  • Close-up anal fin.
  • Close-up pectoral fin.
  • Close-up pelvic fin.
  • Notice the solid color, the deeply forked tail, the "free" adipose fin, the steep profile, and relatively small eye.
  • Close-up anal fin: There are 30-36 rays, including rudimentaries, the margin is straight.
  • Close-up head: The upper jaw is longer than the lower; the profile is steep and the eye is lateral and relatively small.
  • Close-up inside of mouth: Notice the absence of horn-like backward lateral extensions from the tooth patch on the roof of the mouth.
  • Notice the lack of spots even in small fish; the anal fin base is longer than the post-orbital distance.
  • Side view of a young-of-year: Juveniles are similar to adults, but with relatively larger eyes.
  • Side view of a yearling: Juveniles are similar to adults, but with relatively larger eyes.
DescriptionSimilar Species
Family
Bullhead Catfishes (Ictaluridae)
Body
Mouth and Snout: Subterminal mouth and patches of numerous fine teeth on jaws. 8 obvious barbels (4 pairs: 2 pairs on chin, 1 pair on side of upper jaw near the corner of the mouth, and 1 pair on top of snout). Body Pattern: Solid color, bluish gray, olive, or cream; belly white. Fins and barbels moderately to darkly pigmented (chin barbels often white). No scales. Body shape and size: Body dorso-ventrally flattened with a tapered head; in cross-section approximately oval (with a long horizontal axis) to round with a flattened ventral surface. Typically 500-800 mm (20-32 in) TL; maximum reported in 1550 mm (62 in).
Fins
Forked tail. Single dorsal with 1 stout spine and 6 rays, attached by membrane. Pelvic fins abdominal. Adipose fin present. Anal fin with 30-36 rays (including rudimentary rays).
Distinguishing Characteristics
Obvious barbels. See also similar species information.
Breeding Adults
Similar to non-breeders.
Juveniles
Similar to adults, with a generally lighter color (photos).
Hybrids
None reported from Wisconsin.
Compare Similar Species
Anal Fin
Catfish, Blue30-36, edge straight
Catfish, Channel24-27, edge rounded
Catfish, Flathead14-16, edge rounded
Color Pattern
Catfish, BlueSolid at all ages
Catfish, ChannelSpotted as juveniles, small adults solid as large adults
Catfish, FlatheadMottled with dark brown or black, mottling tending to disappear in adults
Head
Catfish, BlueSteep, straight or slightly concave profile; eye smaller and more lateral
Catfish, ChannelRelatively shallow, rounded profile; eye relatively large and dorsal
Catfish, FlatheadBroadly flattened, with short but wide horizontal mouth
Similarity Index
Catfish, BlueN/A
Catfish, ChannelVery similar
Catfish, FlatheadModerately similar
Comments
Catfish, BlueNot native to WI, but has been stocked in the past - not established
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