- Side view adult.
- Side view adult.
- Side view adult.
- Top views of a pregnant female (top) and a breeding male (bottom).
- 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 of a post-spawn male.
- Close-up head: The mouth is terminal to slightly subterminal; there is no frenum.
- Notice the "X", "Y", and "W" shaped blotches on the side; there are 37-50 lateral line scales.
- Close-up dorsal fin: The 1st dorsal fin has 7-9 spines, the 2nd dorsal fin has 11-14 rays, with little or no gap between lobes.
- Close-up flank: The sides are light colored with "X", "Y", and "W" shaped blotches.
- Close-up anal fin: The anal fin has 1 spine and 7-9 rays.
- Head-on view: Notice the stripe around the snout with a gap at the tip; there is no frenum.
- Side view of a breeding male: Males are much darker.
- Side view of a breeding male: Males are much darker with faint black vertical bars.
- Side view of a breeding male (top), and a breeding female (bottom): Notice that the males are much darker.
- Side view of a breeding female (top), and a breeding male (bottom): Notice that males are much darker.
- Alternative view of the caudal region.
- Comparison of Johnny darter (top), and least darter (bottom): Notice that both have a strong similarity in appearance.
Mouth and snout: Mouth terminal to slightly subterminal, horizontal, minute teeth on jaws. No barbels. Body patterning, color, and scales: Back and upper sides tan or olive with dark blotches and speckling; sides tan to straw with several “W”, “Y” and “X” shaped blotches along lateral line and often fine spots present on upper sides (but see Breeding Adult); belly white. Dorsal and caudal fin spotted, other fins lightly pigmented or clear. 37-50 ctenoid lateral scales. Body shape and size: Body fusiform to cylindrical and elongated; round to oval in cross section. Typically 35-65 mm (1.5-2.5 in) TL; maximum about 75 mm (3 in).
Tail, dorsal and other fins: Rounded or square tail. Dorsal fin with 2 lobes, slightly attached to slightly separate, the first with 7-9 (usually 8) spines and the second with 11-14 (usually 13) rays. Pelvic fins thoracic. Adipose fin absent. Anal fin with 1 spine and 7-9 rays.
The johnny darter can be distinguished by its lack of a frenum (i.e., no connection between upper lip and snout; gap between them continuous), its single anal spine, its light body with dark “X”, “W”, and “Y” markings (except in breeding males), by its lack of a modified scale between the pelvic fins, and its single anal spine. See also similar species information.
Males get very dark with black vertical bars on sides.
Similar to adults.
|Darter, Western Sand||11-13%|
|Darter, Western Sand||Absent|
|Darter, Bluntnose||Continuous over snout|
|Darter, Crystal||Continuous over snout|
|Darter, Iowa||Gap at tip of snout|
|Darter, Johnny||Gap at tip of snout|
|Darter, Least||Continuous or gap at tip|
|Darter, Western Sand||Absent or gap at tip|
|Darter, Western Sand||1/9-12|
|Darter, Bluntnose||8-9/9-11, lobes separate|
|Darter, Crystal||14/14-16, lobes close|
|Darter, Iowa||8-12/10-12, lobes separate|
|Darter, Johnny||7-9/11-14, lobes close|
|Darter, Least||5-7/9-10, lobes close|
|Darter, Western Sand||10-12/9-12, lobes far apart|
|Darter, Bluntnose||52-58, <25 pored|
|Darter, Crystal||9-95, all pored|
|Darter, Iowa||55-65, <35 pored|
|Darter, Johnny||37-50, all pored|
|Darter, Least||32-38, 0-7 pored|
|Darter, Western Sand||69-81, all pored|
|Darter, Bluntnose||Very similar|
|Darter, Crystal||Very similar|
|Darter, Iowa||Very similar|
|Darter, Least||Very similar|
|Darter, Western Sand||Very similar|