Minnesota is home to three species of bullheads. It can be a little tricky to identify one species from another, but you’ll probably know right away that it is a bullhead.
All bullhead species have an adipose fin between their dorsal and tail fins. This small fleshy fin lacks any hard, internal structures such as bone or cartilage. It feels much like your ear lobe. Bullheads have a rounded tail which will help you distinguish them from small channel catfish that have a forked tail. Bullheads have no scales, their bodies are covered with taste buds, and will be very slippery to handle. Finally, bullheads have a single, sharp spine in the dorsal and pectoral fins. Like other members of the Catfish Family, bullheads also have barbels (‘whiskers’) under their chin that help them located food.
Ameriurus melas - From the Greek words ameiurus meaning unforked caudal fin; and melas meaning black in color.
Color: Greenish brown to black on the dorsal side and yellow on the ventral, with a light colored bar at the base of the tail fin.
Ameriurus natalis: from the Greek word ameiurus meaning unforked caudal fin; and the Latin word natalis meaning "having large buttocks".
Color: Yellowish brown to black with yellow belly.
Ameriurus nebulosus: from the Greek word ameiurus meaning unforked caudal fin; and the Latin word nebulosus meaning clouded.
Color: Body is yellowish to black, but tends toward yellowish brown mottled with dark green. Yellow coloration on belly and lack of light bar at the base of the caudal fin.
Bullheads eat a variety of aquatic invertebrates such as crayfish, freshwater mussels, snails, and insects. They will also eat other fish, fish eggs, and plants. They will eat almost anything that can fit into their mouths.
Bullheads are common throughout Minnesota's many lakes, rivers, and streams, but they are more common in the southern half of the state. They prefer slow moving, quiet waters that have soft bottoms made up of mud, sand, and gravel. They are able to tolerate turbid or murky/muddy water that many fish cannot. Bullheads are able to survive water with low oxygen content and often occur in large numbers in lakes that winter kill when other fish die out. In short, bullheads can live in just about any aquatic habitat.
While there are some differences in how each bullhead species approaches reproduction, there are some generalizations we can make within this group.
In Minnesota, the spawning season for the bullheads starts in late spring and goes through early summer, when water temperatures are about 68-70° F. The female uses her fins to clean out a saucer-shaped nest in shallow water. She will seek out a location underneath matted vegetation, fallen trees, or overhanging banks. When the male swims near the nest, the female pokes his stomach with her head. Eventually, the two fish sit in the nest next to each other, facing opposite directions. The male touches the female's head with his tail fin repeatedly until she releases eggs. The male fertilizes them immediately. They repeat this spawning act several times over an hour or more and then again over the next few days until the female has laid all her eggs. Both parents fan and guard the eggs.
Once the eggs hatch, the male takes over parental care. He will continue to protect the young until they reach the size of about 1 inch in length. The young fish swim around in a tight little ball and any stragglers are chased back into the ball by the parents. Even after the parents leave, the young will continue to swim in a group (called a school) for many days as they begin to feed. Watch for these schools in the shallows of most lakes in early summer.
Bullheads have a single large, sharp spine at the leading edge of their dorsal and pectoral fins. When bothered, they lock these spines in a straight-out position making the fish very hard to swallow. They also produce a mild poison that runs down the spines and into the wound of a victim punctured by one of these spines. While the poison causes a stinging or burning sensation if you are punctured, it is essentially harmless to humans. The protective and the species' preference for eating mostly at night make bullheads an uncommon prey for other fish. Walleyes, northern pike, flathead catfish, turtles, great blue herons and otters eat small bullheads up to four inches long. People eat larger bullheads.
For more information go to the May 2012 Fishing Equipment & Tips article: Catching and Handling Bullheads and Catfish.