- 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 flanks show a dark mottled color; most of the pelvic fin is behind the origin of the dorsal fin.
- The sides show dark vertical bars; most of the pelvic fin is behind the origin of the dorsal fin.
- Snout and upper lip are connected and the groove is not continuous over the snout.
- Breeders are similar to non-breeders except for a yellow-green iridescence at the anterior base of the anal fin, which is somewhat elongated.
- Alternative side view of an adult.
- Close-up underside of head: Notice the branchiostegal rays.
- Alternative side view.
Mouth and snout: Terminal, slightly oblique, with lower jaw slightly longer than upper and small teeth on jaws. No barbels. Body patterning, color, and scales: Mottling and irregular blotches or numerous irregular dark vertical band or bars. Background color tan, olive or brown, mottling/bars dark brown or black, belly cream, tan, or yellow brown. Fins brown. Lateral line absent; 34-37 cycloid lateral scales. Body shape and size: Body fusiform to cylindrical; in cross section approximately round. Typically 50-100 mm (2-4 in) TL; maximum about 140 mm (4.5 in).
Tail, dorsal and other fins: Rounded tail. Single dorsal with no spines and 13-15 rays. Pelvic fins abdominal. Adipose fin absent. Anal fin with 7-9 rays.
The central mudminnow can be distinguished based on its dark brown mottled or thickly barred color pattern, its terminal mouth lacking a continuous groove between the upper lip and snout, and its positioning of pelvic fins such that most of the fin is behind the origin of the dorsal fin. See also similar species information.
Similar to non-breeders, although males have an elongated anal fin with iridescent light blue-green highlights.
Similar to adults.
|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||Superior mouth with continuous groove between upper lip and snout|
|Mosquitofish, Western||Superior mouth with continuous groove between upper lip and snout|
|Mudminnow, Central||No continuous groove between upper lip and snout|
|Topminnow, Blackstripe||Superior mouth with continuous groove between upper lip and snout|
|Topminnow, Starhead||Superior mouth with continuous groove between upper lip and snout|
Position of Pelvic Fin
|Killifish, Banded||Most or all of fin in advance of origin of dorsal fin|
|Mosquitofish, Western||Most or all of fin in advance of origin of dorsal fin|
|Mudminnow, Central||Behind origin of dorsal fin|
|Topminnow, Blackstripe||Most or all of fin in advance of origin of dorsal fin|
|Topminnow, Starhead||Most or all of fin in advance of origin of dorsal fin|
|Killifish, Banded||Moderately similar|
|Mosquitofish, Western||Moderately similar|
|Topminnow, Blackstripe||Moderately similar|
|Topminnow, Starhead||Moderately similar|
|Mosquitofish, Western||Not established in WI, but stocked in the past and known from Illinois north of Chicago|