The Nonindigenous Occurrences section of the NAS species profiles has a new structure. The section is now dynamically updated from the NAS database to ensure that it contains the most current and accurate information. Occurrences are summarized in Table 1, alphabetically by state, with years of earliest and most recent observations, and the tally and names of drainages where the species was observed. The table contains hyperlinks to collections tables of specimens based on the states, years, and drainages selected. References to specimens that were not obtained through sighting reports and personal communications are found through the hyperlink in the Table 1 caption or through the individual specimens linked in the collections tables.

Ameiurus sp.
Ameiurus sp.
(bullhead catfish)
Native Transplant

Copyright Info
Ameiurus sp. Rafinesque, 1820

Common name: bullhead catfish

Taxonomy: available through www.itis.govITIS logo

Identification: There are seven recognized species in the genus Ameiurus, but stock fishes are most likely A. melas (black bullhead)A. natalis (yellow bullhead), or A. nebulosus (brown bullhead) .

Bullhead catfish are distinguishable by their barbels located near the corners of their mouth, a broad head, spiny caudal and pectoral fins, and no scales. Bullhead catfish (and even Pylodictis olivaris (flathead catfish), can be distinguished from Ictalurus punctatus (channel catfish) and I. furcatus (blue catfish) by their squared tailfins, rather than forked. 

Size: The sizes vary, but black bullheads are the largest of the three species (47.8 cm, 1.8 kg; Trautman 1981)

Native Range: Bullhead catfishes are native to the eastern portion of the North American continental divide, from their westernmost point in central Montana, south to Texas, in streams to the Gulf of Mexico and Atlantic Coast, and north to Canada (Hardman and Lawrence 2003). 

Hydrologic Unit Codes (HUCs) Explained
Interactive maps: Point Distribution Maps

Nonindigenous Occurrences:

Table 1. States with nonindigenous occurrences, the earliest and latest observations in each state, and the tally and names of HUCs with observations†. Names and dates are hyperlinked to their relevant specimen records. The list of references for all nonindigenous occurrences of Ameiurus sp. are found here.

StateFirst ObservedLast ObservedTotal HUCs with observations†HUCs with observations†
ID196719945Brownlee Reservoir; Idaho Falls; Lower Boise; Salmon Falls; Upper Snake-Rock

Table last updated 7/16/2024

† Populations may not be currently present.

Ecology: Bullheads are habitat generalist found in ponds, rivers, oxbows, and lakes. Bullheads are tolerant of low oxygen condition and brackish water. They are nocturnal omnivore benthic feeders eating virtually anything, including detritus (dead material), insects, crayfish, fish, fish eggs, and macroalgae (Trautman 1981).

Means of Introduction: Stocked for sport

Impact of Introduction: Bullheads can inflict a sting with their pectoral fin spines. The pain can last for a week or more. The sting is caused by small glands near their fins that produce a poison which causes swelling (Etnie and Starnes 1993).

References: (click for full references)

Etnier, D.A., and W.C. Starnes. 1993. The fishes of Tennessee. The University of Tennessee Press, Knoxville, TN.

Hardman, M. and Lawrence, P.M. 2003. Phylogenetic relationships among bullhead catfishes of the Genus Ameiurus (Siluriformes: Ictaluridae). Copeia 1:20-33.

Trautman, M.B. 1981. The fishes of Ohio. Ohio State University Press, Columbus, OH.

Other Resources:

Author: Daniel, W.M.

Revision Date: 9/20/2019

Peer Review Date: 9/20/2019

Citation Information:
Daniel, W.M., 2024, Ameiurus sp. Rafinesque, 1820: U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/FactSheet.aspx?speciesID=2920, Revision Date: 9/20/2019, Peer Review Date: 9/20/2019, Access Date: 7/16/2024

This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.


The data represented on this site vary in accuracy, scale, completeness, extent of coverage and origin. It is the user's responsibility to use these data consistent with their intended purpose and within stated limitations. We highly recommend reviewing metadata files prior to interpreting these data.

Citation information: U.S. Geological Survey. [2024]. Nonindigenous Aquatic Species Database. Gainesville, Florida. Accessed [7/16/2024].

Contact us if you are using data from this site for a publication to make sure the data are being used appropriately and for potential co-authorship if warranted.

For general information and questions about the database, contact Wesley Daniel. For problems and technical issues, contact Matthew Neilson.