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.

Culaea inconstans
Culaea inconstans
(Brook Stickleback)
Native Transplant

Copyright Info
Culaea inconstans (Kirtland, 1840)

Common name: Brook Stickleback

Synonyms and Other Names: five-spined stickleback

Taxonomy: available through www.itis.govITIS logo

Identification: Scott and Crossman (1973); Becker (1983); Smith (1985); Page and Burr (1991).

Size: 8.7 cm.

Native Range: Atlantic and Arctic drainages from Nova Scotia to Northwest Territories; Great Lakes-Mississippi River basins south to southern Ohio and New Brunswick, and west to Manitoba and eastern British Columbia (Page and Burr 1991). Whittier collected it in the St. Johns drainage in Maine and determined it was native there (T. Whittier, pers. comm.).

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 Culaea inconstans are found here.

StateFirst ObservedLast ObservedTotal HUCs with observations†HUCs with observations†
AL195619561Pickwick Lake
CA199219962Lower Klamath; Scott
CO198620054Rio Grande Headwaters; San Luis; Upper Arkansas-Lake Meredith; Upper Yampa
CT196919923Housatonic; New England Region; Outlet Connecticut River
KY198019866Licking; Licking; Lower Kentucky; Lower Levisa; South Fork Kentucky; Upper Levisa
ME198019801Lower Androscoggin River
MA200520051Ashuelot River-Connecticut River
MT1994202124Arrow; Big Dry; Bitterroot; Blackfoot; Box Elder; Boxelder; Bullwhacker-Dog; Cut Bank; Flathead Lake; Judith; Little Dry; Lower Powder; Lower Yellowstone-Sunday; Marias; O'Fallon; Stillwater; Sun; Swan; Teton; Upper Missouri-Dearborn; Upper Yellowstone; Upper Yellowstone-Lake Basin; Upper Yellowstone-Pompeys Pillar; Willow
NE200820081Upper White
NM196919903Canadian Headwaters; Rio Grande-Albuquerque; Upper Canadian-Ute Reservoir
NY193520103Owego-Wappasening; Upper Susquehanna; Upper Susquehanna
OK196319631Arkansas-White-Red Region
PA197519751Upper Juniata
SD201820181Middle Cheyenne-Spring
TN198819932Lower Clinch; Obey
UT198320204Lower Green-Diamond; Lower Weber; Strawberry; Utah Lake
VT201820191Winooski River
WA199920233Palouse; Rock; San Juan Islands

Table last updated 7/13/2024

† Populations may not be currently present.

Means of Introduction: Many introductions have been attributed to bait bucket releases. According to Smith-Vaniz (1968), the Alabama record was based on a single specimen, and was likely the result of an escape or release from a minnow hatchery located several miles downstream. Holding tanks at the hatchery contained stickleback, and the species was frequently observed in shipments of commercial bait minnows brought to Alabama from Wisconsin. Nelson (1969) also reported the species as commonly found with Pimephales promelas in baitfish shipments from Minnesota and Wisconsin. In certain southwestern localities, the species may have been introduced accidentally as a contaminant in stockings of sport fishes. For instance, Hatch (1985, cited by Sublette et al. 1990) believed that the presence of this species in New Mexico was the result of baitbucket introductions or introduced incidental to stocking of salmonids. He based his conclusions on the fact that this stickleback had not been found in New Mexico prior to 1954 and that headwaters of the Canadian River drainage are popular with trout anglers. Zuckerman and Behnke (1986) suggested that the Colorado Division of Wildlife may have accidentally introduced the species into the Rio Grande drainage of Colorado waters along with northern pike brought in from Minnesota. Pigg et al. (1993) discovered Brook Stickleback in a bait shipment of fathead minnows from Minnesota and suggested a possible link between its introduction into Oklahoma and the bait fish industry. A much earlier report in Oklahoma is apparently based on observations of this species in bait tanks near Ft. Gibson Reservoir in Wagoner County (Heard 1959). The owner of the bait establishment said the minnows were imported from Minnesota. The retailer had noticed the dace mixed in the primarily fathead minnow bait shipments that he had been purchasing and re-selling for over a year. Although, there are no verified records from open waters, at least some individuals were likely introduced through discarded or escaped bait. Bait bucket release is also thought to be the source of the introduced populations in Montana (Fredenberg, personal communication).

It was introduced to two sites in Utah in 1983 (Sigler and Sigler 1987), possibly intentional stockings as forage. The species was first discovered in California in 1991, but the means of introduction remains unknown (Dill and Cordone 1997). Denoncourt et al. (1975c) were uncertain as to the origin of this species in the Susquehanna River drainage of Pennsylvania; they stated that the populations may be natural or the result of accidental introductions.

Status: Reported from Alabama, Kentucky, Minnesota, and Oklahoma. The species is no longer present in Utah (Sigler and Sigler 1996). According to Whitworth (1996), it has not been found in Connecticut since the report by Whitworth et al. (1968). It has been introduced to Tennessee on several occasions resulting in populations of varied persistence; the White Oak Creek system population is considered to be locally established in that state (Etnier and Starnes 1993). Koster (1957) reported that it is likely extirpated in New Mexico because its only known locality was poisoned. In Montana, it was introduced into Swan Lake within the past five years or so and has become established there. It was first taken in nearby Flathead Lake in 1997. A single individual was collected in 1997 and four more in 1998 (Fredenberg, personal communication). The species is established or possibly locally established in other states mentioned. Established in eastern Washington (Scholz et al. 2003).

Impact of Introduction: Largely unknown. Woodling (1985) stated that the species is pugnacious and preys on eggs. As such, he said that its use as a bait fish is discouraged so as to prevent accidental range expansion.

Remarks: Zuckerman and Behnke (1986) indicated that there is uncertainty as to whether Culaea inconstans is introduced or native to the Rio Grande drainage. Stickleback found in some New Mexico minnow ponds may have been introduced; however, the population inhabiting the headwaters of the Canadian River drainage, New Mexico, may represent a glacial relict (Nelson 1969). Page and Burr (1991) clearly agreed with that conclusion. However, Sublette et al. (1990) presented strong evidence to support the hypothesis that the species' presence in New Mexico is the result of introduction. In a recent study, Gach (1996) found that the disjunct population in New Mexico shares identical mitochondrial DNA restriction profiles with Michigan populations and likely represents an accidental introduction rather than a Pleistocene relict. She also found evidence indicating that Culaea had been introduced into parts of Michigan including the Saline River and the Huron River drainage. Apparently, these were sites where the species is already native, but the introduction caused a change in the genetic composition of existing populations. The Saline River introduction reportedly occurred in 1967 and involved Culaea that had contaminated a commercial shipment of Pimephales promelas used in a toxicity study. Woodling (1985) recorded the presence of C. inconstans from the South Platte drainage and Arkansas River system in eastern Colorado. Based on the conclusions of others, he suggested its occurrence in these drainages represented native records. Similarly, Propst and Carlson (1986) provisionally listed C. inconstans as indigenous to the Platte River drainage of Colorado. However, Page and Burr (1991) did not include Colorado within the species' native range. Nelson (1969) indicated that a few early workers included Kansas in the range limits of Culaea; however, he concluded that such a southern extreme was doubtful. According to Etnier and Starnes (1993), Tennessee formerly prohibited import of this species into the state based on the unlikely notion that their sharp spines posed a potential hazard to sport fishes. Because sticklebacks are highly aggressive, Zuckerman and Behnke (1986) felt there was a need to address the impact of their introduction on native fish communities. Woodling (1985) felt that the species is not a very good bait fish. Nevertheless, it is occasionally found in bait buckets.

Voucher specimens: Montana (MSU).

References: (click for full references)

Boschung, H.T. 1992. Catalogue of freshwater and marine fishes of Alabama. Alabama Museum of Natural History Bulletin 14:1-266.

Branson, B.A., and D.L. Batch. 1983. Fishes of the South Fork of the Kentucky River, with notes and records from other parts of the drainage. Proceedings of the Southeastern Fishes Council 4:1-15.

Burr, B.M., and M.L. Warren, Jr. 1986. A distributional atlas of Kentucky fishes. Kentucky Nature Preserves Commission Scientific and Technical Series 4. 398 pp.

Cordone, A.J. - Department of Fish and Game, Sacramento, CA. Response to NBS-G non-indigenous questionaire. 1992.

Denoncourt, R.F., C.H. Hocutt, and J.R. Stauffer, Jr. 1975. Additions to the Pennsylvania ichthyofauna of the Susquehanna River drainage. Proceedings of the Academy of Natural Sciences of Philadelphia 127(9):67-69.

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

Heard, W.R. 1959. Live bait imports: Chrosomus eos and Eucalia inconstans as potential additions to Oklahoma's fish fauna. Proceedings of the Oklahoma Academy of Science (for 1956) 37:47-48.

Hocutt, C.H., R.E. Jenkins, and J.R. Stauffer, Jr. 1986. Zoogeography of the fishes of the central Appalachians and central Atlantic coastal plain. Pages 161-212 in Hocutt, C.H., and E.O. Wiley, eds. The zoogeography of North American freshwater fishes. John Wiley and Sons. New York, NY.

Jones, R.A. - Fisheries Bureau, Departments of Environmental Protection, Hartford, CT. Response to NBS-G nonindigenous questionaire. 1992.

Koster, W.J. 1957. Guide to the fishes of New Mexico. University of New Mexico Press, Albuquerque, NM.

Lee, D.S., C.R. Gilbert, C.H. Hocutt, R.E. Jenkins, D.E. McAllister, and J.R. Stauffer, Jr. 1980. Atlas of North American freshwater fishes. North Carolina State Museum of Natural History, Raleigh, NC.

Moore, G.A., and C.D. Riggs. 1963. Checklist of known Oklahoma fishes. Pages 41-44 in Oklahoma Wildlife Commission. Know Your Oklahoma Fishes. Department of Wildlife Conservation, Oklahoma City, OK.

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.

Scholz, A.T., B.Z. Lang, A.R. Black, H.J. McLellan, and R.L. Peck. 2003. Brook stickleback established in eastern Washington. Northwest Science 77(2):110-115.

Smith-Vaniz, W.F. 1968. Freshwater fishes of Alabama. Auburn University Agricultural Experiment Station, Auburn, AL. 211 pp.

Sublette, J.E., M.D. Hatch, and M. Sublette. 1990. The fishes of New Mexico. New Mexico Department of Game and Fish, University of New Mexico Press, Albuquerque, NM. 393 pp.

Woodling, J. 1985. Colorado's Little Fish: a guide to the minnows and other lesser known fishes in the state of Colorado. Colorado Division of Wildlife, Denver, CO.

Zuckerman, L.D., and R.J. Behnke. 1986. Introduced fishes in the San Luis Valley, Colorado. Pages 435-452 in R. H. Stroud, editor. Fish culture in fisheries management. Proceedings of a symposium on the role of fish culture in fisheries management at Lake Ozark, MO, March 31-April 3, 1985. American Fisheries Society, Bethesda, MD.

Other Resources:
FishBase Summary

Author: Fuller, P.

Revision Date: 4/21/2022

Peer Review Date: 5/5/2010

Citation Information:
Fuller, P., 2024, Culaea inconstans (Kirtland, 1840): U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/FactSheet.aspx?SpeciesID=701, Revision Date: 4/21/2022, Peer Review Date: 5/5/2010, Access Date: 7/13/2024

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 [7/13/2024].

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.