Fathead Minnow
  • 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.
  • The fathead minnow has 43-49 lateral line scales and a diffuse lateral stripe without a distinct caudal spot.
  • The snout is rounded/trianglular, and the mouth is terminal and oblique and does not extend to the front of the eye.
  • Anterior top view: The scales between the head and dorsal fin are small and relatively crowded compared with the flanks.
  • View of intestines: The peritoneum is black, and the digestive tract is long.
  • Close-up anal fin: There are seven anal fin rays.
  • Head of a breeding male: Notice the black head and the tubercles.
  • Side view of a breeding male: Breeding males develop a dark color on the body and fins, interspersed with light vertical bands.
  • Close-up dorsal fin of a breeding male: The first dorsal ray is shortened and thickened and widely spaced from the second.
  • Dorso-lateral view of a breeding male: Breeding males develop a gray spongy tissue in the dorso-lateral area.
  • Side view of a breeding male: Breeding males develop a dark color on the body and fins.
  • Side view of a breeding male: Breeding male at the beginning of spawning--the dark color on the body and fins is not as dark yet.
  • Side view of a young-of-year: Juveniles are similar to adults, but not quite as deep-bodied.
DescriptionSimilar Species
Family
Minnows (Cyprinidae)
Body
Mouth and snout: Mouth terminal and oblique to superior and almost vertical, without any teeth. No barbels. Snout triangular to rounded. Body patterning, color, and scales: Silver, gray, olive, brown, or tan, sometimes with a black lateral stripe, often missing or faint in larger fish, yielding a solid color on flanks, grading to white or cream on the belly (but see Breeding Adults below). Dorsal fin sometimes with a dark pigment blotch on first 2-3 membranes. Sometimes a spot at the base of the tail, usually not distinct from lateral stripe. Other fins without distinctive markings (but see Breeding Adults below). 43-49 cycloid lateral line scales, rounded in shape. Body shape and size: Body generally fusiform, fairly deep in adults, oval in cross section. Typically 25-65 mm (1-2.5 in) TL; maximum from Wisconsin about 90 mm (3.5 in).
Fins
Tail, dorsal and other fins: Forked tail with rounded tips. Single dorsal fin with 8 rays and no spines. Pelvic fins abdominal. No adipose fin. Anal fin with 7 rays and no spines.
Distinguishing Characteristics
Scales on back between head and dorsal fin (predorsal scales) smaller, more numerous, and more crowded together than scales in a comparably sized area of the flank; 43-49 lateral line scales; 7 anal fin rays; terminal or superior mouth, oblique to almost vertical, does not reach front of eye; triangular to rounded snout; peritoneum black and digestive tract 1.4-1.7 TL. See also similar species information.
Breeding Adults
Males – Dark body, almost black, especially the head, with lighter (brownish, dark tan, or gold) vertical bands just behind the head and under the dorsal fin. Most fin rays, especially at the base of the dorsal, outlined with dark pigment; edges of all but caudal fin generally clear. 1st ray of dorsal fin thickened and shortened and widely spaced from 2nd ray. Obvious large tubercles on snout. Grayish “pad” of spongy tissue in dorso-lateral area behind head.
Juveniles
Similar to adults, but less deep bodied.
Hybrids
None confirmed from Wisconsin.
Compare Similar Species
Scales
Chub, CreekPredorsal scales small and crowded; 49-66 lateral line scales
Chub, HornyheadPredorsal scales similar to flank scales; 38-48 lateral line scales
Minnow, BluntnosePredorsal scales small and crowded; 40-44 lateral line scales
Minnow, BullheadPredorsal scales small and crowded; 40-45 lateral line scales
Minnow, FatheadPredorsal scales small and crowded; 43-49 lateral line scales
Minnow, OzarkPredorsal scales similar to flank scales; 36-38 lateral line scales
Anal Fin
Chub, Creek8 rays
Chub, Hornyhead7 rays
Minnow, Bluntnose7 rays
Minnow, Bullhead7 rays
Minnow, Fathead7 rays
Minnow, Ozark8 rays
Mouth and Snout
Chub, CreekMouth terminal, slightly oblique, extending to almost middle of eye; snout triangular
Chub, HornyheadMouth subterminal, slightly oblique, extending to front of eye; snout triangular
Minnow, BluntnoseMouth subterminal, nearly horizontal, extending to front of eye; snout blunt to rounded
Minnow, BullheadMouth terminal to slightly subterminal, slightly oblique, extending to front of eye; snout triangular to rounded
Minnow, FatheadMouth terminal or superior, oblique or nearly vertical, does not extend to eye; snout triangular to rounded
Minnow, OzarkMouth subterminal, slightly oblique, extending to front of eye; snout triangular
Digestive Tract
Chub, CreekShort tract, 0.6-0.7 total length; peritoneum silvery or gray
Chub, HornyheadRelatively long tract, ~0.9 total length; peritoneum dusky to brownish
Minnow, BluntnoseRelatively long tract, 1.0-1.2 total length; peritoneum black
Minnow, BullheadShort tract, 0.6-0.7 total length; peritoneum silvery
Minnow, FatheadLong tract, 1.4-1.7 total length; peritoneum black
Minnow, OzarkVery long tract, 1.9-2.4 total length; peritoneum black
Similarity Index
Chub, CreekModerately similar
Chub, HornyheadModerately similar
Minnow, BluntnoseModerately similar
Minnow, BullheadModerately similar
Minnow, FatheadN/A
Minnow, OzarkModerately similar
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