Iowa Darter
  • 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 sides are mottled with 9-12 blotches/bars; there are 55-65 lateral line scales of which <35 are pored.
  • Close-up head: Notice the terminal or slightly subterminal mouth and the frenum; the cheeks are scaled.
  • The 1st dorsal fin has 8-12 spines, the 2nd has 10-12 rays; there is a gap between lobes.
  • The sides are mottled with 9-12 irregular blotches/vertical bars; there are 55-65 lateral line scales and 12-14 pectoral rays.
  • Close-up pelvic fin of a male: Notice the narrowly attached opercles, the cream throat, and normal-sized pelvic fins.
  • The anal fin has 2 spines and 7-9 rays.
  • Two breeding male with blue vertical bars interpresed with red, the 1st dorsal fin displays blue, red, and blue bands.
  • Breeding male with blue vertical bars interpresed with red, the 1st dorsal fin displaying blue, red, and blue bands.
  • Breeding male with blue vertical bars interpresed with red, the 1st dorsal fin displays blue, red, and blue bands.
  • Close-up flank of a breeding male: Notice the blue vertical bars interpresed with red, the 1st dorsal fin displays blue, red, and blue bands.
  • Breeding male with blue vertical bars interpresed with red, 1st dorsal fin shows blue, red, and blue bands.
  • Breeding male with blue vertical bars interpresed with red, the 1st dorsal fin displaying blue, red, and blue bands.
  • Alternative side view.
  • Alternative view of anal fin.
  • Alternative view of dorsal fin of a male.
  • Alternative view of the head region.
  • Alternative top view.
  • Alternative side view of four specimens.
  • Alternative view of dorsal fin of a male.
DescriptionSimilar Species
Family
Perches (Percidae)
Body
Mouth and snout: Mouth terminal to slightly subterminal, horizontal, minute teeth on jaws. No barbels. Body patterning, color, and scales: Back brown with faint blotches; usually a distinct boundary between the back and lateral pigmentation. Sides mottled with 9-12 dark blotches or often irregular vertical bars, not extending onto dorsal or ventral surface. Belly white, tan, or light olive. First dorsal with dark lower half, then lighter band, then dark margin. Second dorsal and caudal fin spotted, other fins lightly pigmented or clear. 55-65 ctenoid lateral scales. Body shape and size: Body fusiform to cylindrical and elongated; round to oval in cross section. Typically 35-50 mm (1.5-2 in) TL; maximum about 75 mm (3 in).
Fins
Tail, dorsal and other fins: Rounded or square tail. Dorsal fin with 2 lobes, clearly separated, the first with 8-12 (usually 9) spines and the second with 10-12 (usually 11) rays. Pelvic fins thoracic. Adipose fin absent. Anal fin with 2 spines and 7-9 (usually 8) rays.
Distinguishing Characteristics
The Iowa darter can be distinguished by its 55 or more lateral-line scales, its pigment/color pattern, and by its lack of a modified scale between the pelvic fins. See also similar species information.
Breeding Adults
Males with vertical bars more pronounced and better defined, bars greenish-blue with brick red in-between them. Upper sides of belly reddish-yellow or reddish-orange, ventral area and throat cream. First dorsal with dark greenish-blue base, than orange-red on light band (finely outlined in yellow), then greenish-blue margin. Orange-red wash on 2nd dorsal, greenish-blue on anal and pelvic fins.
Juveniles
Similar to adults.
Hybrids
None confirmed from Wisconsin.
Compare Similar Species
Body Depth/SL
Darter, Bluntnose14-18%
Darter, Crystal11-13%
Darter, Iowa14-18%
Darter, Johnny14-18%
Darter, Least16-20%
Darter, Western Sand11-13%
Frenum
Darter, BluntnoseAbsent
Darter, CrystalPresent
Darter, IowaPresent
Darter, JohnnyAbsent
Darter, LeastPresent
Darter, Western SandAbsent
Snout Stripe
Darter, BluntnoseContinuous over snout
Darter, CrystalContinuous over snout
Darter, IowaGap at tip of snout
Darter, JohnnyGap at tip of snout
Darter, LeastContinuous or gap at tip
Darter, Western SandAbsent or gap at tip
Anal Spines/Rays
Darter, Bluntnose1/7-9
Darter, Crystal1/15-16
Darter, Iowa2/7-9
Darter, Johnny1/7-9
Darter, Least1-2/5-6
Darter, Western Sand1/9-12
Dorsal Spines/Rays
Darter, Bluntnose8-9/9-11, lobes separate
Darter, Crystal14/14-16, lobes close
Darter, Iowa8-12/10-12, lobes separate
Darter, Johnny7-9/11-14, lobes close
Darter, Least5-7/9-10, lobes close
Darter, Western Sand10-12/9-12, lobes far apart
Lateral Scales
Darter, Bluntnose52-58, <25 pored
Darter, Crystal9-95, all pored
Darter, Iowa55-65, <35 pored
Darter, Johnny37-50, all pored
Darter, Least32-38, 0-7 pored
Darter, Western Sand69-81, all pored
Similarity Index
Darter, BluntnoseVery similar
Darter, CrystalVery similar
Darter, IowaN/A
Darter, JohnnyVery similar
Darter, LeastVery similar
Darter, Western SandVery similar
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