- 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 belly: The scales on the belly and between the pelvic fins are enlarged and toothed.
- Close-up tail: The tail has 23-25 scales around the caudal peduncle.
- The sides show 10-16 blotches/bars, 65-71 lateral line scales, and an orange band on the 1st dorsal lobe.
- Close-up mouth: The mouth is small and subterminal without obvious teeth, the snout is pointed and elongated.
- Close-up dorsal fin: The 1st dorsal lobe shows dark pigments on the lower half, then orange, then dark, and then a light edge.
- Close-up flank: The flank has 10-16 blotches/vertical bars and 65-71 lateral line scales.
- Breeders are similar to non-breeders; but male pigments, especially orange, may be more intense.
- Alternative side view.
Mouth and snout: Mouth slightly subterminal, horizontal, minute teeth on jaws. No barbels. Body patterning, color, and scales: Back olive, brown, or tan with small dark blotches or saddles. Sides lighter colored with 10-16 dark blotches or irregular vertical bars. Belly cream or tan. Second dorsal and caudal fins lightly barred, other fins lightly pigmented or clear. 65-71 ctenoid lateral scales. Body shape and size: Body fusiform to cylindrical and elongated; round to oval in cross section. Typically 60-75 mm (2.5-3 in) TL; maximum in Wisconsin about 85 mm (3.5 in).
Tail, dorsal and other fins: Square to slightly forked tail. Dorsal fin with 2 lobes, distinctly separate, the first with 12-13 (usually 12) spines and the second with 12-14 (usually 14) rays. Pelvic fins thoracic. Adipose fin absent. Anal fin with 2 spines and 9-10 rays.
The slenderhead darter can be distinguished by its small-to-moderate (not extending beyond the anterior of eye) terminal or subterminal mouth without obvious canine teeth, the presence of one or more enlarged and heavily toothed scales between the pelvic fins, plus usually a row of enlarged toothed scales along the midline in males and a partially naked belly in females. See also similar species information.
Similar to non-breeders, orange in first dorsal of male may be more intense.
Similar to adults.
None known from Wisconsin.
|Darter, Blackside||Rounded, not elongated|
|Darter, Gilt||Rounded, not elongated|
|Darter, River||Rounded, not elongated|
|Darter, Slenderhead||Pointed, elongated|
|Logperch||Conical protuberance, somewhat elongated|
|Darter, Blackside||6-11 oval blotches along lateral line, stripe-like, blotches or saddles on back|
|Darter, Gilt||5-8 thick squarish vertical bars or blotches extending on to back|
|Darter, River||8-11 blotches, thick and irregular in back, grading to thin vertical ars in front|
|Darter, Slenderhead||10-16 blotches or irregular vertical bars on sides, back|
|Logperch||15-25 narrow vertical bars|
1st Dorsal Fin Pigmentation
|Darter, Blackside||Solid pigment on lower half, grading to dusky on outer third, thin light edge|
|Darter, Gilt||Solid pigment, orangish in life, except for thin clear/white edge|
|Darter, River||Dusky, with small dark blotch in front, larger dark blotch on posterior membranes|
|Darter, Slenderhead||Dark pigment on lower 1/2, then orange (in life), then dark band, then light edge|
|Logperch||Dusky lateral bands on light background|
Lateral Line Scales
|Darter, Blackside||~10 long gill rakers, 20-23 CP scales, 12-15 D1 spines|
|Darter, Gilt||~11 long gill rakers, 24-29 CP scales, 11-12 D1 spines|
|Darter, River||~9 short gill rakers, 19-24 CP scales, 10-12 D1 spines|
|Darter, Slenderhead||~10 short gill rakers, 23-25 CP scales, 12-13 D1 spines|
|Logperch||~12 short gill rakers, 24-37 CP scales, 13-15 D1 spines|
|Darter, Blackside||Very similar|
|Darter, Gilt||Very similar|
|Darter, River||Very similar|
|Darter, Blackside||CP=caudal peduncle, D1=1st dorsal fin|
|Darter, Gilt||CP=caudal peduncle, D1=1st dorsal fin|
|Darter, River||CP=caudal peduncle, D1=1st dorsal fin|
|Darter, Slenderhead||CP=caudal peduncle, D1=1st dorsal fin|
|Logperch||CP=caudal peduncle, D1=1st dorsal fin|