Fathead Minnow

Pimephales promelas

Fathead_Minnow_Pimephales_promelas_Female_7-25-13.jpg

Fathead minnow side view photo with black background
Fathead minnow, Pimephales promelas
Lance Merry
Other Common Name
Toughie
Family

Cyprinidae (minnows) in the order Cypriniformes (carps, minnows and loaches)

Description

The fathead minnow is chubby, with a blunt, rounded snout, short, rounded fins, a dusky stripe along the midside, and a spot at the base of the tail fin. Breeding males are mostly black with yellowish bars encircling the body behind the head and beneath the dorsal fin, and a distinctive fleshy pad that develops behind the head only during the spawning season.

Size

Total length: 1 1/2 to 2 3/4 inches; maximum about 3 inches.

Fathead_Minnow_Pimephales_promelas_Spawning_male_7-25-13.jpg

Fathead minnow male in spawning colors, side view photo with black background
Fathead Minnow Male in Spawning Colors
Fathead minnow, Pimephales promelas, male in spawning coloration
Habitat and conservation

Lives in schools in mid water or near the bottom. Occurs in streams of all sizes but is most abundant only in the pools of small prairie creeks, because of its tolerance for high temperatures, extreme turbidity, and low oxygen. Such relatively high water temperatures and low oxygen levels commonly occur during dry, summer weather, when prairie creeks sometimes recede to a series of shallow pools. Also occurs in shallow, silty sloughs along the floodplains of prairie rivers.

Foods

Omnivorous, feeding on mostly algae and other plant material with some animal matter ― aquatic insects and small crustaceans.

image of Fathead Minnow distribution map
Distribution in Missouri

Occurs in small prairie streams in northern Missouri where it is most abundant in intermittent pools.

Life cycle

Spawning occurs in our state in May through August. Eggs are deposited on a variety of submerged objects, and males remain with the eggs until they hatch. Males release a waterborne chemical substance that attracts females to the site. As many as 12,000 eggs have been found in a single nest. A female may spawn more than 12 times in a single summer and produce 4,000 or more offspring. Individuals rarely live longer than three years.

Human connections

This hardy fish is well-suited for propagation in ponds. It is often stocked as prey for game fish and is commonly sold for bait. It seldom is abundant enough in waters containing large game fish populations to be of much value as a forage fish.

Ecosystem connections

Because it survives in stagnant pools of intermittent prairie creeks in midsummer, this species, with the hardy creek chub, black bullhead, and green sunfish, often constitute the entire fish population of such creeks. In habitats supporting many other fishes, fathead minnows are seldom abundant.