Northern Studfish

Appearance

The mean length for adults is 3 to 6 inches . Northern studfish are sexually dimorphic. Males have horizontal rows of bright orange spots on light blue background and a bright orange tail margin followed by a nearly black band during breeding season. Females are more cryptic colored in shades of beige and olive. Their body shape is elongate and narrow and lacks a lateral line. Northern studfish have spineless fins and both the anal and dorsal fins are large.

Distribution

Upper East Fork White River system, Indiana; upper Salt and Kentucky River drainages, Kentucky; upper Green middle, and lower Cumberland, and Tennessee River drainages, Virginia, Kentucky, Tennessee, Alabama, and Mississippi; West of Mississippi River in central and southern Missouri, southeastern Kansas, eastern Oklahoma and southern Arkansas; southwestern Mississippi in the Mississippi drainage and Gulf Slope drainage . Live bait buckets and releases of aquarium pets has caused expansion of the native distribution of this species.

Habitat

Northern studfish are egg layers and prefer clear, shallow pools and rocky creeks that have a mixed sand/gravel substrate and constant, sluggish flow. Males do not build nests but they do stake out a territory and defend it. Females lay a clutch of 28 to 245 eggs and give no parental care to their young. Their main diet consists of insects which they skim from the surface of the water but they have also been known to consume snails.