Connecticut Department of Energy & Environmental Protection

Fathead Minnow (Pimephales promelas) - Introduced

7 cm fathead minnow.

A 3-inch fathead minnow. Note that the lateral line is incomplete (does not extend along the entire body of the fish).

Identification. Similar to bluntnose minnow. Adults thick-bodied. Forked tail with rounded lobes. Blunt snout. Mouth reaches end of snout. No conspicuous markings. First ray of dorsal fin short and thickened. Lateral line incomplete and not outlined in black. Spot at base of tail fin faint. Distinctive thin black lines between muscle fibers on the upper sides. Grayish to brownish on back fading to silvery gray on sides and white on belly. 

Close up of fathead minnow dorsal fin.

Close-up of the dorsal fin of a fathead minnow showing the short, thickened first ray that is characteristic of the genus.

Size. Commonly 2 to 3 inches. State survey max. size 3.9 inches. Max. reported size 3.9 inches.

Distribution. Widespread throughout much of North America. Especially common in the Central United States. Have been widely introduced. Can be sporadically found at low abundance almost anywhere in Connecticut. 

Fathead minnow distribution map.

Habits. Can be found in a wide range of habitats including ponds and streams. Fatheads are tolerant of poor water quality, high water temperatures and low oxygen. Easy to keep in home aquariums.

Comments. Fathead minnows are a popular baitfish and are also commonly imported and stocked in small private ponds to supply forage for gamefish. We are not aware of any permanent self-sustaining populations in Connecticut, although they may exist in some small, private ponds. Fatheads found in public waters are probably the result of recent bait bucket releases or fish that have washed downstream from stocked ponds. 

Swimming fathead minnow.

Aquarium photo of a fathead minnow.


Text and images adapted from Jacobs, R. P., O'Donnell, E. B., and Connecticut DEEP. (2009). A Pictorial Guide to Freshwater Fishes of Connecticut. Hartford, CT. Available for purchase at the DEEP Store. The fish distribution maps were created in 2009. For updated fish distributions please use the CT DEEP Fish Community Data Interactive Map.