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 insignis
Noturus insignis
(Margined Madtom)
Native Transplant

Copyright Info
Noturus insignis (Richardson, 1836)

Common name: Margined Madtom

Taxonomy: available through www.itis.govITIS logo

Identification: The Margined Madtom has a light cream-colored belly, a light brown to grey back and chin barbells. There are no blotches or saddle marks on this fish's back and sides as found on other madtoms. Its dorsal and caudal fins are light brown with black edges, its adipose fin is attached along the length of the body and is continuous with the square caudal fin. Smith (1985); Page and Burr (1991); Jenkins and Burkhead (1994).

Size: Up to 15 cm

Native Range: Atlantic Slope from the Delaware drainage, New York, to upper Altamaha River drainage, Georgia; upper Kanawha (New) River system, Virginia; upper Monongahela River system, Pennsylvania and Maryland (Page and Burr 1991); Lake Ontario (Roth et al., 2011).

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 insignis are found here.

StateFirst ObservedLast ObservedTotal HUCs with observations†HUCs with observations†
MD197719943Monongahela; Pokomoke-Western Lower Delmarva; Youghiogheny
MA198619872Merrimack River; Winnipesaukee River
MI196619942Great Lakes Region; Manistique River
NH193720093Merrimack River; New England; Pemigewasset River
NY190720197Mohawk; Oak Orchard-Twelvemile; Oneida; Oswego; Schoharie; Seneca; St. Lawrence
NC194920134Albemarle; Nolichucky; Upper New; Watauga, North Carolina, Tennessee
PA198619973Lower Monongahela; Upper Ohio; Youghiogheny
TN196420062Lower French Broad; Watauga, North Carolina, Tennessee
VA193620173Middle New; North Fork Holston; Upper New
WV199319972Greenbrier; Monongahela

Table last updated 5/19/2024

† Populations may not be currently present.

Ecology: Gutowski and Stauffer (1993) found that the Margined Madtom preferentially feeds on baetid, chironomid, and simuliid larvae. Locomotory activity levels increased after dusk as is common for most species of madtom. According to catch per effort data, this fish was most active near midnight (Gutowski and Stauffer 1993).

Means of Introduction: Many of these occurrences may have been the result of bait bucket introductions (Taylor 1969; Jenkins and Burkhead 1994).

Status: The margined madtom is native to Lake Ontario, but introduced to Lakes Superior and Huron; it is currently absent from Lakes Michigan and Erie (Roth et al. 2011).

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: Taylor (1969) and Jenkins and Burkhead (1994) discussed native and possible nonnative distribution. Hocutt et al. (1986) listed this species as native but possibly introduced into the Monongahela drainage.  Smith (1985) considers the native range to includethe Black watershed which drains into Lake Ontario atthe headwaters of the St. Lawrence River.

References: (click for full references)

Cooper, E.L. 1983. Fishes of Pennsylvania. Pennsylvania State University Press, University Park, PA.
Emery, L. 1985. Review of fish introduced into the Great Lakes, 1819-1974. Great Lakes Fishery Commission Technical Report, volume 45, 31 pp.

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

Gutowski, M.J. and J.R. Stauffer, Jr. 1993. Selective predation by Noturus insignis (Richardson) (Teleostei: Ictaluridae) in the Delaware River. American Midland Naturalist 129(2): 309-318
Hartel, K.E. 1992. Non-native Fishes Known from Massachusetts Freshwaters. Occasional Reports of the Museum of Comparative Zoology, Harvard University, Fish Department, Cambridge, MA. 2. September. pp. 1-9.

Jenkins, R.E., and N.M. Burkhead. 1994. Freshwater Fishes of Virginia. American Fisheries Society, Bethesda, MD.

Menhinick, E.F. 1991. The Freshwater Fishes of North Carolina. North Carolina Wildlife Resources Commission. 227 pp.

Mills, E.L., J.H. Leach, J.T. Carlton, and C.L. Secor. 1993. Exotic species in the Great Lakes: a history of biotic crisis and anthropogenic introductions. Journal of Great Lakes Research 19(1):1-54.

Page, L.M., and B.M. Burr. 1991. A Field Guide to Freshwater Fishes of North America North of Mexico. The Peterson Field Guide Series, volume 42. Houghton Mifflin Company, Boston, MA.

Phelps, A., and A. Francis. 2002. Update COSEWIC status report on the margined madtom Noturus insignis in Canada, in COSEWIC assessment and update status report on the margined madtom Noturus insignis in Canada. Committee on the Status of Endangered Wildlife in Canada, Ottawa, 17 pp.

Roth, B., N. Mandrak, G. Sass, T. Hrabik, J. Peters. 2011. Ichthyofauna of the Great Lakes Basin. Proceedings of the American Fisheries Society 140th Annual Meeting

Scarola, J.F. 1973. Freshwater Fishes of New Hampshire. New Hampshire Fish and Game Department, Division of Inland and Marine Fisheries. 131 pp.

Smith, C.L. 1985. The Inland Fishes of New York State. New York State Department of Environmental Conservation, Albany, NY. 522 pp.

U.S. Fish and Wildlife Service. 1994a. Endangered and threatened wildlife and plants: animal candidate review for listing as endangered or threatened species. 50 CFR 17.11 & 17.12. Federal Register, November 15, 1994. 59(219):58982-589028. U.S. Department of the Interior, Washington, DC.

Welsh, S.A., and D.A. Cincotta. 2004. Natural hybrids of the madtoms Noturus flavus and Noturus insignis, from the Monongahela River Drainage, West Virginia. Northeastern Naturalist 11(4):399-406.

FishBase Summary

Author: Fuller, P., G. Jacobs, J. Larson, A. Fusaro, and M. Neilson

Revision Date: 1/19/2024

Peer Review Date: 3/26/2014

Citation Information:
Fuller, P., G. Jacobs, J. Larson, A. Fusaro, and M. Neilson, 2024, Noturus insignis (Richardson, 1836): U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/FactSheet.aspx?SpeciesID=748, Revision Date: 1/19/2024, Peer Review Date: 3/26/2014, Access Date: 5/19/2024

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 [5/19/2024].

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