What's In a Name?
Fathead minnow: refers to the enlarged head of breeding males

Pimephales (pie-meff´-al´-ezz) means "fathead" in Greek
promelas (pro-mell´-oss) literally "before black" in Greek, possibly referring to the darkened head of the original specimen

How Big Do They Get?
How Long Do They Live?
Fatheads only grow to about 65-70 mm (2.6-2.8 in), and males grow bigger than females. Most of these little fish live for only 1 year. Less than 20 % of 1-year-olds live to 2 years old. On rare occasions a fathead makes it to 3 years old.

What Eats Them?
In lakes and deeper streams, fatheads are common prey for crappies, rock bass, perch, walleyes, largemouth bass, and northern pike. They also are eaten by snapping turtles, herons, kingfishers, and terns. Eggs of the fathead are eaten by painted turtles and certain large leeches. Although humans do not eat fatheads, they harvest them as bait.

How Do They Reproduce?
Spawning season for the fathead minnow starts in late May to early June when water temperature exceeds 16° C (about 60° F). It goes into mid-August when the water temperatures begin to cool. About 30 days before a male begins to spawn, he develops dark coloration, breeding tubercles (which resembles little horns) on his head, and a soft mucus-like pad on his back between his head and dorsal fin. The male selects the nest site, which normally is under an object such as a log, rock, stick, pop can, or whatever may be dumped at the bottom of the waterway. The bottom of the waterway is commonly made up of gravel or sand, which easily can be moved. The male excavates enough of the bottom to be able to fit easily under the nest object. He then defends it aggressively from all other fatheads. Often females have to be very persistent to gain admission to the nest. Once the female enters the nest she turns upside down and lays her sticky eggs on the underside of the nest object. She then leaves to either spawn with another male or go back to where she came from. After the female leaves the nest, the male then fertilizes the eggs. The male not only guards his incubating eggs; he fans them with his fins and massages them with his back pad. This keep them clean and well oxygenated. Other females may add eggs to the nest as the spawn season goes on. The male continues his care until all of the eggs hatch. Females produce clutches of eggs (groups of eggs that become ready for spawning at the same time). Each clutch may contain 80-370 eggs. Most females probably spawn several clutches in a season. We do not know the actual number. The embryos hatch in about 4-6 days.

Conservation and Management
Fathead minnows are probably the most abundant minnow in Minnesota, and so they have no special conservation status. Fatheads are the premier bait minnow in Minnesota and are collected from the wild by anglers and commercial bait dealers. They also are reared in ponds for the bait industry.

"Cool Fact": The fathead minnow was used in the past as a form of mosquito control in many Metro Area ponds, ditches, and sloughs.