The brown bullhead (Ameiurus nebulosus) is a fish of the family Ictaluridae that is widely distributed in North America. It is a species of bullhead catfish and is similar to the black bullhead (Ameiurus melas) and yellow bullhead (Ameiurus natalis). It was originally described as Pimelodus nebulosus by Charles Alexandre Lesueur in 1819, and is also referred to as Ictalurus nebulosus.
The brown bullhead is also widely known as the "mud pout", "horned pout", "hornpout", or simply "mud cat", a name also used with the other bullhead species.
The brown bullhead is important as a clan symbol of the Ojibwe people. In their tradition, the bullhead or is one of six beings that came out of the sea to form the original clans.
Appearance
The brown bullhead grows to be approximately in length and is a darker brown-green dorsally, growing lighter green and yellow towards the ventral surface. The belly is off-white or cream, and the fish has no scales. Additionally, there are darker, brown-black speckles along the entire surface of the fish. The brown bullhead has a dorsal fin that bears a spine, a single adipose fin posterior to the dorsal fin, abdominal pelvic fins, and an anal fin with 21 to 24 rays. The tail is only slightly notched, with the dorsal and ventral lobes angling inward. The pectoral fins have spines that bear five to eight serrated teeth on their posterior edge. The fish has eight barbels around its mouth. The barbels on the chin are black to yellowish brown. Juvenile brown bullheads are similar in appearance, but are more likely to be of a single solid color. Adult brown bullheads range in size from and weigh between and (in extreme cases). However, there is evidence that the brown bullhead was historically absent from the Gulf Coast west of the Apalachicola River and east of the Mississippi River. The species is also abundant in many regions as a result of stocking for food or sport. These locations include Georgia, Alabama, Arizona, Arkansas, California, Colorado, Hawaii, Idaho, Kansas, Kentucky, Louisiana, Maine, Missouri, Nebraska, Nevada, New Hampshire, New Mexico, Ohio, Oklahoma, Oregon, Virginia, and Washington. Brown bullheads are a social non-migratory species that are known to form schools. They eat insects, leeches, snails, fish, clams, and many plants. They are also known to eat corn, which can be used as bait. Similarly to other catfish, they spawn only after the temperature of the water has reached in June and July. However, cooler temperatures are required before brown bullheads will spawn in the northern US.
thumb|left|Brown bullhead, Ameiurus nebulosus Brown bullheads can withstand a wide range of water temperatures and low oxygen levels. Brown bullheads can survive waters with heavy pollution and dissolved oxygen values as low as 0.2ppm.
Fishing
This catfish is easily caught with natural bait such as worms and chicken livers. They have a scrappy but not unusually strong fight. Anglers often catch them by fishing off the bottom. When caught in very clear water when the flesh is firm and reddish to pinkish, the hornpout is quite edible and delicious. Nevertheless, its genial cousins such as the channel catfish and the blue catfish are better known for their use as food. In most areas, they will not exceed two pounds in weight, with a current International Game Fish Association world record of .
Life cycle and reproduction
thumb|Brown bullhead [[roe]]
Brown bullheads typically live between six and eight years, For the duration of each breeding season, females will be monogamous.
As an invasive species
The fish has been introduced into many European countries, such as Poland, Germany, Sweden, Norway, Finland, Romania, Estonia, Hungary, Serbia, and Croatia. Brown bullheads have also been introduced to western North America, Chile, Puerto Rico and New Zealand.
Countries who have reported adverse effects from the introduction of the brown bullhead species include Iran and Turkey.