- 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.
- Notice the thin dark lateral stripes; the dorsal origin is behind the anal origin, the pelivc fins are ahead of the dorsal origin.
- The side shows dark vertical bars (faint) and 30-34 lateral line scales; the dorsal origin is behind the anal origin.
- Close-up mouth/snout: The mouth is superior; there is a bar/blotch below the eye and a groove between upper snout and lip.
- Close-up head: The mouth is superior; there is a bar/blotch below the eye and a groove between upper snout and lip.
- The female (top) shows thin lateral stripes, the male (bottom) shows thin vertical bars and a relatively large anal fin.
- Side view of a breeding male: Males develop thin dark vertical bars and a relatively large anal fin.
- Comparison starhead topminnow, female (top) and male (bottom), and blackstripe topminnow (middle): Notice the differences in stripe and bar patterns.
- Alternative side view of an adult.
Killifishes and topminnows (Fundulidae)
Mouth and snout: Superior with small teeth in jaws. No barbels. Body patterning, color, and scales: Tan to olive flanks with thin dark olive vertical bars or several thin dark olive lateral stripes (often consisting of rows of fine spots). Dark bar or blotch under eye. Belly cream or white. Fins generally lightly pigmented or clear but sometimes with faint stripes or spots at the base of the dorsal, anal, and tail fins. Lateral line absent; 30-34 cycloid lateral scales. Body shape and size: Body fusiform and relatively deep, somewhat laterally compressed; oval cross section. Typically 35-50 mm (1.5-2 in) TL; maximum in Wisconsin about 62 mm (2.5 in).
Tail, dorsal and other fins: Rounded tail. Single dorsal with no spines and 8-9 rays. Pelvic fins abdominal. Adipose fin absent. Anal fin with 11 rays.
The starhead topminnow can be distinguished by its lack of dark mottling and thick vertical bars, its superior mouth with a continuous groove between the snout and upper lip, and its positioning of the pelvic fin such that all or most of the fin is in advance of the origin of the dorsal fin. See also similar species information.
Males have vertical bars but females do not. Anal and dorsal fins are also larger in males (photos).
Similar to adults.
Dorsal Fin Origin
|Killifish, Banded||Ahead of anal origin|
|Mosquitofish, Western||Behind anal origin|
|Mudminnow, Central||Ahead of anal origin|
|Topminnow, Blackstripe||Behind anal origin|
|Topminnow, Starhead||Behind anal origin|
Color and Pigment Pattern
|Killifish, Banded||Silvery with irregular dark vertical bars (often faint) on flanks; no dark bar or blotch below eye|
|Mosquitofish, Western||Solid tan or olive, sometimes with fine spots, especially dorsally; dark bar or blotch below eye|
|Mudminnow, Central||Dark olive green to brown black, mottled with up to 14 distinct to vague dark brown vertical bars; belly yellow to white; dark bar or blotch below eye|
|Topminnow, Blackstripe||Olive with thick dark lateral stripe, sometimes with finer incomplete vertical bars giving stripe a zig-zag appearance; no dark bar or blotch below eye|
|Topminnow, Starhead||Olive or silvery with either fine dark vertical bars or lateral stripes (consisting of rows of fine spots); dark bar or blotch below eye|
|Killifish, Banded||Very similar|
|Mosquitofish, Western||Very similar|
|Mudminnow, Central||Moderately similar|
|Topminnow, Blackstripe||Very similar|
|Mosquitofish, Western||Not established in WI, but stocked in the past and known from Illinois north of Chicago|