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.

Noturus exilis
Noturus exilis
(Slender Madtom)
Native Transplant

Copyright Info
Noturus exilis Nelson, 1876

Common name: Slender Madtom

Taxonomy: available through www.itis.govITIS logo

Identification: Becker (1983); Robison and Buchanan (1988); Page and Burr (1991); Etnier and Starnes (1993); Pflieger (1997).

Size: 15 cm.

Native Range: Green, Cumberland, and Tennessee River drainages from central Kentucky to nothern Alabama; and the upper Mississippi River basin from southern Wisconsin and southern Minnesota to Ozark an Ouachia Highlands of Arkansas, Kansas, and Oklahoma (Page and Burr 1991).
Native range data for this species provided in part by NatureServe NS logo
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 Noturus exilis are found here.

StateFirst ObservedLast ObservedTotal HUCs with observations†HUCs with observations†
AR197119761Mountain Fork

Table last updated 6/21/2024

† Populations may not be currently present.

Means of Introduction: Possible bait release; alternatively, this collection could represent an unusual natural distribution pattern that may give clues to past river connections (Robison and Winters 1978; Robison and Buchanan 1988).

Status: Reported in Arkansas.

Impact of Introduction: The impacts of this species are currently unknown, as no studies have been done to determine how it has affected ecosystems in the invaded range. The absence of data does not equate to lack of effects. It does, however, mean that research is required to evaluate effects before conclusions can be made.

Remarks: This species had never been collected in this area previously, despite intensive sampling, making it unlikely that this species was native but overlooked. In addition, this species is known to be used as bait in the area (Robison and Winters 1978). An additional five specimens were taken from Mill Creek (tributary of Mt. Fork River, Red River drainage) by C.R. Gilbert in 1971 (UF 22742) (Robison and Buchanan 1988).

Other Resources:
FishBase Summary

Author: Fuller, P.

Revision Date: 12/2/1999

Peer Review Date: 12/2/1999

Citation Information:
Fuller, P., 2024, Noturus exilis Nelson, 1876: U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/FactSheet.aspx?SpeciesID=744, Revision Date: 12/2/1999, Peer Review Date: 12/2/1999, Access Date: 6/21/2024

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 [6/21/2024].

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