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Brown catfish

Ameiurus nebulosus

What do they look like?

Brown bullhead are overall brown in color with black mottling or spots on their sides. The body is scaleless and is a dark brown or black on the back, and lighter brown on the lower half of the body. In captivity, this species loses pigmentation, becoming whitish. Their most distinguishing features are black barbels (which look like whiskers) on their faces that help the fish feel their environment and sense chemical changes in the water. They have 8 barbels total that are located on the nose, upper lip, and chin.

They have terminal mouths with a slightly longer upper jaw and a mouth filled with irregular rows of tiny teeth on both jaws. They have one dorsal fin, an adipose fin (above the tail), and a tail fin with a slightly indented fork. Typical adult length is 200 to 300 mm but they may reach up to 500 mm. Adults usually weigh 0.5 kg, but have been recorded at 3.6 kg. No significant difference has been found between male and female size. (Baily, et al., 2004; Barnes and Hicks, 2003; Becker, 1983; Blumer, 1985; Michigan Department of Natural Resources and Environment, 2010; Nelson, 1984; Page and Burr, 1991; Rasquin, 1949; University of Wisconsin Center for Limnology, et al., 2010)

  • Sexual Dimorphism
  • sexes alike
  • Range mass
    3.6 (high) kg
    7.93 (high) lb
  • Average mass
    0.5 kg
    1.10 lb
  • Range length
    500 (high) mm
    19.69 (high) in
  • Average length
    200-300 mm
    in

Where do they live?

Brown bullhead are native to freshwater habitats in Canada and the United States from 25° to 54° north latitude. They are distributed in the Atlantic and Gulf Slope drainages, ranging from Nova Scotia and New Brunswick to Mobile Bay, Alabama, and in the Great Lakes, Hudson Bay, and Mississippi basins from Quebec west to southeast Saskatchewan and south to Louisiana.

Brown bullhead have been introduced outside of this range, including countries of northern, western, and eastern Europe, the Middle East, New Zealand, Chile, and Puerto Rico (United States). They have also been introduced and well established in the western United States and British Columbia. (American Fisheries Society, 2004; Barnes and Hicks, 2003; Fisheries and Oceans Canada, 2010; Froese and Pauly, 2010; Page and Burr, 1991)

What kind of habitat do they need?

Brown bullhead are found in pools and slower-moving areas of creeks and rivers, reservoirs, ponds, and lakes. They are tolerant of a wide range of environmental conditions, including warm water temperatures and low oxygen levels. They prefer habitats with vegetation and substrate. They survive well in domestically and industrially polluted waters. They are bottom dwelling fish. (Barnes and Hicks, 2003; Becker, 1983; Blazer, et al., 2009a; Blazer, et al., 2009b; Fisheries and Oceans Canada, 2010; Froese and Pauly, 2010; Page and Burr, 1991)

How do they grow?

Mean daily water temperature during reproduction is 14 to 29 degrees Celsius. Once brown bullhead egg clusters are released and fertilized, they take up to 13 days to hatch. Egg diameter is about 2.2 to 2.7 mm. The larval stage lasts 4 to 9 days. Hatched larvae are 4 to 8 mm long, lay on nests during early development, and survive on their yolk-sacs. Metamorphosis occurs between the larval and juvenile stage. Juveniles remain in schools with other juveniles. (Becker, 1983; Blumer, 1985; Eycleshymer, 1901)

How do they reproduce?

Brown bullhead are monogamous during the breeding season, which means that one male and one female will form a mating pair. Courtship, occurring near nesting sites, involves holding the partners jaw, tail, or head with the mouth, head butting, nibbling bodies, and touching barbels. Side-by-side swaying has also been observed. (Becker, 1983; Blumer, 1985; Encyclopedia of Life, 2010)

Brown bullhead spawn once a year during the spring and early summer breeding season. In Michigan, most brown bullhead spawn in early June. Fish are able to reproduce at 3 years old. Nests, typically built by females but sometimes by pairs, are holes dug in the sand, gravel, mud, under roots, and within the shelter of logs and vegetation in shallow water. Pebbles from the river bottom are sucked into the mouth and relocated during nest building. Sheltered nests are thought to provide protection from predators. During nest construction males are territorial and will defend the area around their nest. Brown bullhead females lay eggs which are fertilized externally by males. Egg clusters contain 50 to 10,000 eggs. (Barnes and Hicks, 2003; Becker, 1983; Blumer, 1985; Eycleshymer, 1901; Michigan Department of Natural Resources and Environment, 2010)

  • How often does reproduction occur?
    Brown bullhead spawn once during a breeding season.
  • Breeding season
    The breeding season is during the spring and early summer.
  • Range number of offspring
    50 to 10,000
  • Range time to hatching
    13 (high) days
  • Average time to hatching
    5.6 days
  • Average time to independence
    9.4 days
  • Average age at sexual or reproductive maturity (female)
    3 years
  • Average age at sexual or reproductive maturity (male)
    3 years

Eggs are laid on river bottoms and are incubated and guarded by one or both parents who fan the eggs with their fins, which may keep the eggs healthy and help with development. After hatching, larvae on the nest and schooling juveniles are guarded by one or both parents who chase away other fish. If juveniles leave the school, parents will capture them and return them with their mouths. Juveniles are cared for most often by males. Maximum length of parental care is 29 days. (Becker, 1983; Blumer, 1985; Blumer, 1986a; Blumer, 1986b)

  • Parental Investment
  • male parental care
  • female parental care
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • male
      • female
  • pre-weaning/fledging
    • protecting
      • male
      • female
  • pre-independence
    • protecting
      • male
      • female

How long do they live?

Brown bullhead live 6 to 8 years. Maximum age of brown bullhead is 9 years. Predation pressure is strongest during the egg and larval stages. (Blumer, 1986b; Froese and Pauly, 2010; Michigan Department of Natural Resources and Environment, 2010)

  • Range lifespan
    Status: wild
    9 (high) years
  • Average lifespan
    Status: wild
    6 to 8 years

How do they behave?

Brown bullhead are a non-migratory species. They are social fish that spend time in schools (or groups) with other fish. They are most active at night. During the breeding season, brown bullheads become very territorial and will chase away other fish that get too close to their nests. (Blazer, et al., 2009a; Blazer, et al., 2009b)

Home Range

Home range sizes of brown bullheads are not reported.

How do they communicate with each other?

Brown bullhead can make sounds underwater, likely produced by rubbing body parts together. In laboratories, they produce sound during aggressive encounters with other brown bullheads. (Anderson, et al., 2008; Fine, et al., 1997; Helfman, et al., 2009)

What do they eat?

Brown bullhead forage on river bottoms, and are opportunistic omnivores which means they will eat almost anything they come across. In aquarium settings they eat most food given to them. Juveniles eat zooplankton, insects, including mayfly larvae and caddisfly larvae, and plants. Adults feed on insects, small fish, fish eggs, mollusks, plants, leeches, worms, and crayfish. They typically are nocturnal feeders, but have been observed feeding during the day. They use their face barbels to locate food. (Barnes and Hicks, 2003; Becker, 1983; Fisheries and Oceans Canada, 2010; Froese and Pauly, 2010; Kline and Wood, 1996; Raney and Webster, 1940)

  • Animal Foods
  • fish
  • eggs
  • insects
  • mollusks
  • terrestrial worms
  • aquatic or marine worms
  • aquatic crustaceans
  • zooplankton

What eats them and how do they avoid being eaten?

Predators of brown bullhead include northern pike, muskellunge, walleye, snapping turtles, water snakes, and green herons. Bluntnose minnows and shiner minnows, yellow perch, and sunfishes are the most common predators on eggs.

Brown bullhead are brown and black in color which serves as camouflage. They blend in well with the rocky river bottoms they inhabit. (Becker, 1983; Blumer, 1986b; Michigan Department of Natural Resources and Environment, 2010)

  • These animal colors help protect them
  • cryptic

What roles do they have in the ecosystem?

Brown bullhead are predatory fish and prey on other animals.

Do they cause problems?

There are no known adverse effects of brown bullhead on humans.

How do they interact with us?

Brown bullhead are used in a small scale recreational and commercial fishery in Canada and in the United States. They have been important research animals for the study of sensory hair cells since they have large facial barbels. They are sensitive to changes in water pollution, temperature, and overall water quality and therefore are an important indicator species in pollution studies. (Becker, 1983; Blazer, et al., 2009a; Blazer, et al., 2009b; Bowen, 1931; Christensen, et al., 1972; Fisheries and Oceans Canada, 2010; Lesko, et al., 1996; Michigan Department of Natural Resources and Environment, 2010; Sakaris and Jesien, 2005; West, et al., 2006)

  • Ways that people benefit from these animals:
  • food
  • research and education

Are they endangered?

Brown bullhead are not listed for protection under the IUCN Red List, the United States Endangered Species Program, or under a CITES appendix. (International Union for Conservation of Nature and Natural Resources, 2009; U.S. Fish & Wildlife Service, 2010; United Nations Environment Programme and World Conservation Monitoring Centre, 2010)

Contributors

Rachael Guth (author), Northern Michigan University, Rachelle Sterling (editor), Special Projects, Jill Leonard (editor), Northern Michigan University, Tanya Dewey (editor), University of Michigan-Ann Arbor.

References

American Fisheries Society, 2004. Common and scientific names of fishes from the United States, Canada, and Mexico. Bethesda: American Fisheries Society.

Anderson, K., R. Rountree, F. Juanes. 2008. Soniferous fishes in the Hudson River. Transactions of the American Fisheries Society, 137: 616-626.

Baily, R., W. Latta, G. Smith. 2004. An atlas of Michigan fishes with keys and illustrations for their identification. Ann Arbor: Museum of Zoology, University of Michigan.

Barnes, G., B. Hicks. 2003. Brown bullhead catfish in Lake Taupo. DOC workshop: 27-35.

Becker, G. 1983. Fishes of Wisconsin. Madison: University of Wisconsin Press.

Blazer, V., J. Fournie, J. Wolf, M. Wolfe. 2006. Diagnostic criteria for proliferative hepatic lesions in brown bullhead Ameiurus nebulosus. Diseases of Aquatic Organisms, 72: 19-30.

Blazer, V., S. Rafferty, P. Baumann, S. Smith, E. Obert. 2009. Assessment of the "fish tumors or other deformities" beneficial use impairments in brown bullhead (Ameiurus nebulosus): I. Orocutaneous tumors. Journal of Great Lakes Research, 35: 517-526.

Blazer, V., S. Rafferty, P. Baumann, S. Smith, E. Obert. 2009. Assessment of the "fish tumors or other deformities" beneficial use impairments in brown bullhead (Ameiurus nebulosus): II. Liver neoplasia. Journal of Great Lakes Research, 35: 527-537.

Blumer, L. 1986. Parental care sex differences in the brown bullhead, Ictalurus nebulosus, (Pisces, Ictaluridae). Behavioral Ecology and Sociobiology, 19: 97-104.

Blumer, L. 1985. Reproductive natural history of the brown bullhead Ictalurus nebulosus in Michigan. American Midland Naturalist, 1985: 318-330.

Blumer, L. 1986. The function of parental care in the brown bullhead Ictalurus nebulosus. American Midland Naturalist, 115: 234-238.

Bowen, R. 1931. Movement of the so-called hairs in the ampullar organs of fish ears. Proceedings of the National Academy of Science, 17: 192-194.

Christensen, G., J. McKim, E. Hunt. 1972. Changes in the blood of the brown bullhead (Ictalurus nebulosus (Lesueur)) following short and long term exposure to copper (II). Toxicology and Applied Pharmacology, 23: 417-427.

Encyclopedia of Life, 2010. "Encyclopedia of Life" (On-line). Accessed February 25, 2010 at http.//www.eol.org.

Eycleshymer, A. 1901. Observation on the breeding habits of Ameiurus nebulosus. The American Naturalist, 35: 911-918.

Fine, M., J. Friel, D. McElroy, C. King, K. Loesser, S. Newton. 1997. Pectoral spine locking and sound production in the channel catfish Ictalurus punctatus. Copeia, 1997: 777-790.

Fisheries and Oceans Canada, 2010. "Ontario-Great Lakes area fact sheets" (On-line). Accessed March 09, 2010 at http://www.dfo-mpo.gc.ca.

Froese, R., D. Pauly. 2010. "FishBase" (On-line). Accessed February 25, 2010 at http://www.fishbase.org.

Hardman, M., L. Page. 2003. Phylogenetic relationships among bullhead catfishes of the Genus Ameiurus (Siluriformes: Ictaluridae). Copeia, 2003: 20-33.

Helfman, G., B. Collette, D. Facey, B. Bowen. 2009. The diversity of fishes. United Kingdom: Wiley-Blackwell Publication.

International Union for Conservation of Nature and Natural Resources, 2009. "IUCN Red List of Threatened Species" (On-line). Accessed March 08, 2010 at http://www.iucnredlist.org.

Kline, J., B. Wood. 1996. Food habits and diet selectivity of the brown bullhead. Journal of Freshwater Ecology, 11: 145.

Lesko, L., S. Smith, M. Blouin. 1996. The effects of contaminated sediments on fecundity of the brown bullhead in three Lake Erie tributaries. Journal of Great Lakes Research, 22: 830-837.

Michigan Department of Natural Resources and Environment, 2010. "Natural resources-fishing" (On-line). Accessed March 09, 2010 at http://michigan.gov/dnr.

Nelson, J. 1984. Fishes of the world. New York: Wiley-Interscience Publication.

Page, L., B. Burr. 1991. Peterson field guide-freshwater fishes. Boston: Houghton Mifflin Company.

Raney, E., D. Webster. 1940. The food and growth of the young of the common bullhead, Ameiurus nebulosus nebulosus (LeSueur). Transactions of the American Fisheries Society, 69: 205-209.

Rasquin, P. 1949. Spontaneous depigmentation in the catfish. Copeia, 1949: 246-251.

Sakaris, P., R. Jesien. 2005. Brown bullhead as an indicator species: seasonal movement patterns and home ranges within the Anacostia River, Washington, D.C.. Transactions of the American Fisheries Society, 134: 1262-1270.

Tomelleri, J., M. Eberle. 1990. Fishes of the Central United States. Lawrence: University Press of Kansas.

U.S. Fish & Wildlife Service, 2010. "USFWS Endangered Species Program" (On-line). Accessed March 08, 2010 at http://endangered.fws.gov/wildlife.html.

United Nations Environment Programme, , World Conservation Monitoring Centre. 2010. "CITES Species Database" (On-line). Accessed March 08, 2010 at http://cites.org/eng/resources/species.html.

University of Wisconsin Center for Limnology, , Wisconsin DNR, Wisconsin Sea Grant. 2010. "Wisconsin Fish" (On-line). Accessed February 25, 2010 at http://wiscfish.org.

West, D., N. Ling, B. Hicks, L. Tremblay, N. Kim, M. Van Den Heuvel. 2006. Cumulative impacts assessment along a large river, using brown bullhead catfish (Ameiurus nebulosus) populations. Environmental Toxicology and Chemistry, 25: 1868-1880.

 
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Guth, R. 2011. "Ameiurus nebulosus" (On-line), Animal Diversity Web. Accessed October 23, 2017 at http://www.biokids.umich.edu/accounts/Ameiurus_nebulosus/

BioKIDS is sponsored in part by the Interagency Education Research Initiative. It is a partnership of the University of Michigan School of Education, University of Michigan Museum of Zoology, and the Detroit Public Schools. This material is based upon work supported by the National Science Foundation under Grant DRL-0628151.
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