Ameiurus is a genus of catfish

Catfish

Catfishes are a diverse group of ray-finned fish. Named for their prominent barbels, which resemble a cat's whiskers, catfish range in size and behavior from the heaviest and longest, the Mekong giant catfish from Southeast Asia and the second longest, the wels catfish of Eurasia, to detritivores...

es in the family Ictaluridae

Ictaluridae

The Ictaluridae, sometimes called Ictalurids, are a family of catfish native to North America, where they are important food fish and sometimes as a sport fish. They include fish commonly known as bullheads, madtoms, channel catfish, and blue catfish....

. It contains the three common types of bullhead catfish found in waters of the United States

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

, the black bullhead

Black bullhead

The black bullhead, Ameiurus melas, is a species of bullhead catfish. Like other bullhead catfish, it has the ability to thrive in waters that are low in oxygen, brackish, turbid and/or very warm. It also has barbels located near its mouth, a broad head, spiny fins and no scales...

 (Ameiurus melas), the brown bullhead

Brown bullhead

The brown bullhead, Ameiurus nebulosus, is a fish of the Ictaluridae family that is widely distributed in North America. It is a species of bullhead catfish and is similar to the black bullhead and yellow bullhead...

 (Ameiurus nebulosus), and the yellow bullhead

Yellow bullhead

The yellow bullhead, is a species of bullhead catfish. Yellow bullhead are typically yellow-olive to slatey-black on the back and sometimes mottled depending on habitat. The sides are lighter and more yellowish while the underside of the head and body are bright yellow, yellow white, or bright...

 (Ameiurus natalis), as well as other species, such as the white catfish (Ameiurus catus or Ictalurus catus

Ictalurus catus

Ictalurus catus, also known as the white catfish or white bullhead, is a member of the family Ictaluridae of the order Siluriformes.- Distribution :...

), which are not typically called "bullheads".

The species known as bullheads can be distinguished from channel catfish

Channel catfish

Channel catfish, Ictalurus punctatus, is North America's most numerous catfish species. It is the official fish of Missouri, Iowa, Nebraska, Kansas, and Tennessee, and is informally referred to as a "channel cat". In the United States they are the most fished catfish species with approximately 8...

 and blue catfish

Blue catfish

The blue catfish, Ictalurus furcatus, is one of the largest species of North American catfish. Blue catfish are distributed primarily in the Mississippi River drainage including the Missouri, Ohio, Tennessee, and Arkansas rivers...

 in that their tailfins are squared, rather than forked.

Taxonomy and fossil record

Ameiurus is recognized as monophyletic

Monophyly

In common cladistic usage, a monophyletic group is a taxon which forms a clade, meaning that it contains all the descendants of the possibly hypothetical closest common ancestor of the members of the group. The term is synonymous with the uncommon term holophyly...

, meaning it forms a natural group. It is mostly closely related to the clade

Clade

A clade is a group consisting of a species and all its descendants. In the terms of biological systematics, a clade is a single "branch" on the "tree of life". The idea that such a "natural group" of organisms should be grouped together and given a taxonomic name is central to biological...

 formed by Noturus, Prietella

Prietella

Prietella is a small genus of catfishes of the family Ictaluridae. It includes two species, the phantom blindcat, P. lundbergi, and the Mexican blindcat, P. phreatophila.-Taxonomy:...

, Satan

Widemouth Blindcat

For other uses, see Satan .The widemouth blindcat is a species of catfish of the family Ictaluridae, and the only representative of the genus Satan....

, and Pylodictis genera.

There are seven extant (living) species and eight fossil species of Ameiurus. The oldest, Ameiurus pectinatus, gives a minimum age estimate for the genus at approximately 30 million years, during the Oligocene

Oligocene

The Oligocene is a geologic epoch of the Paleogene Period and extends from about 34 million to 23 million years before the present . As with other older geologic periods, the rock beds that define the period are well identified but the exact dates of the start and end of the period are slightly...

.

There is a sister group

Cladistics

Cladistics is a method of classifying species of organisms into groups called clades, which consist of an ancestor organism and all its descendants . For example, birds, dinosaurs, crocodiles, and all descendants of their most recent common ancestor form a clade...

 relationship between the species A. melas and A. nebulosus.

Distribution

Living species of Ameiurus catfishes are natively distributed east of the North America

North America

North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

n continental divide, from their westernmost point in central Montana

Montana

Montana is a state in the Western United States. The western third of Montana contains numerous mountain ranges. Smaller, "island ranges" are found in the central third of the state, for a total of 77 named ranges of the Rocky Mountains. This geographical fact is reflected in the state's name,...

, south to Texas

Texas

Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...

, in streams of the Gulf of Mexico

Gulf of Mexico

The Gulf of Mexico is a partially landlocked ocean basin largely surrounded by the North American continent and the island of Cuba. It is bounded on the northeast, north and northwest by the Gulf Coast of the United States, on the southwest and south by Mexico, and on the southeast by Cuba. In...

 and Atlantic Coast, north to New Brunswick

New Brunswick

New Brunswick is one of Canada's three Maritime provinces and is the only province in the federation that is constitutionally bilingual . The provincial capital is Fredericton and Saint John is the most populous city. Greater Moncton is the largest Census Metropolitan Area...

 and Quebec

Quebec

Quebec or is a province in east-central Canada. It is the only Canadian province with a predominantly French-speaking population and the only one whose sole official language is French at the provincial level....

, Ontario

Ontario

Ontario is a province of Canada, located in east-central Canada. It is Canada's most populous province and second largest in total area. It is home to the nation's most populous city, Toronto, and the nation's capital, Ottawa....

, Manitoba

Manitoba

Manitoba is a Canadian prairie province with an area of . The province has over 110,000 lakes and has a largely continental climate because of its flat topography. Agriculture, mostly concentrated in the fertile southern and western parts of the province, is vital to the province's economy; other...

, and Saskatchewan

Saskatchewan

Saskatchewan is a prairie province in Canada, which has an area of . Saskatchewan is bordered on the west by Alberta, on the north by the Northwest Territories, on the east by Manitoba, and on the south by the U.S. states of Montana and North Dakota....

.

Habitat

Bullheads live in a variety of habitats, including brackish and/or low oxygen ponds, rivers and lakes, although they are seldom stocked intentionally. They are bottom feeders and eat virtually anything edible, including dead fish, insects, other fish, grain, fruit, crayfish and more. Because of their limited use as food or sport, they are usually caught while trying to catch other fish, and few anglers pursue them specifically. Persons looking to catch bullheads will use the same baits as they would for channel catfish, including cut bait, chicken livers, blood-soaked meal, or other pungent baits. Like all catfish, bullheads have a sense of smell that is more developed than the best canine.

Description and identification

Bullheads do not get as large as the other US native catfishes, with averages sizes in the one to two-pound range and world record sizes well under 10 pounds.

All three major bullheads can be confused with other catfishes by novice anglers. Because they have an unforked tail, many people mistakenly think small flathead catfish are bullheads. Both have the squared tail, and can have a mottled, brown appearance (in the case of the brown bullhead), but the flathead lower lip protrudes farther than its upper lip and it has a flat or "shovel" head. They also have very different habits and habitat.

Flatheads generally eat only live things, while bullheads will freely eat dead fish or other small animals. The flathead is more likely to be found at the bottom of dams or in gravel pits, while bullheads are found more often in the most brackish areas. Additionally, flatheads can reach weights well in excess of 100 pounds, while the current world's record for any bullhead is a black bullhead, recorded at 8 lb even (3.63 kg), while the average adult is perhaps two pounds. Brown and yellow bullheads are significantly smaller.

Relationship to humans

They are considered rough fish

Rough fish

Rough fish is a term used by U.S. state agencies and U.S. anglers to describe fish that are less desirable to sport anglers within a limited region. The term usually refers to larger fish species that are not commonly eaten, are too rare to be commonly encountered, or are not sought after by...

by many, and are seldom caught for food, although they can be quite edible if caught in clear water and prepared correctly. In Minnesota, bullhead are important to commercial fishermen, who harvest about 1 million pounds a year.