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.

Apeltes quadracus
Apeltes quadracus
(Fourspine Stickleback)
Native Transplant

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Apeltes quadracus (Mitchill, 1815)

Common name: Fourspine Stickleback

Taxonomy: available through www.itis.govITIS logo

Identification: The fourspine stickleback has a bony ridge on each side of the abdomen, making it triangular in cross-section, with flat belly and sharp back; it is fusiform from the side view, tapering to a pointed nose and to a slim caudal peduncle. There are two to four free dorsal spines standing close one behind the other, inclining alternately to one side or the other; another spine is attached to the dorsal fin by the fin membrane; the anal fin is similarly preceded by an attached spine, and each ventral fin is represented by a stouter curved spine, strongly saw-edged, followed by about two slender rays. The dorsal fin stands over the anal as in the nine-spined species, but both these fins are more rounded in outline, while the caudal fin is relatively longer and narrower than in any of our other stickleback species. Further details are provided in Scott and Crossman (1973); Smith (1985); Robins et al. (1986); Page and Burr (1991).

Size: 6.4 cm

Native Range: Europe and the Atlantic coast of North America. Atlantic Slope from the Gulf of St. Lawrence to Trent River system, North Carolina. Mostly a nearshore marine species, but far inland populations occur in lakes in Nova Scotia, and in Hudson, Delaware, and Susquehanna River drainages (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 Apeltes quadracus are found here.

StateFirst ObservedLast ObservedTotal HUCs with observations†HUCs with observations†
ME200820081East Branch Penobscot River
MI200020001Lake Superior
MN200120011Lake Superior
PA195119853Connoquenessing; Lower Susquehanna-Swatara; Upper Susquehanna-Lackawanna

Table last updated 6/23/2024

† Populations may not be currently present.

Ecology: The fourspine stickleback can be found in fresh and brackish water from 0 to 3 m deep. Adults inhabit weedy bays and backwaters (Delbeek and Williams, 1988).

Apeltes quadracus often live sympatrically with other species of stickleback throughout their native range, though they are generally solitary with regard to other members of their own species. Individuals are often observed perched among bottom debris and vegetation, never in open water, hovering over a patch of substrate, picking at it frequently, then moving on to another patch (Delbeek and Williams 1987). Delbeek and Williams (1987) also found that fourspine stickleback fed exclusively on the bottom, wither among benthic vegetation or from the substrate, the most abundant organisms in their diets being diatoms, nauplii, nematodes, ostracods, and cyclopods. During spawning, the males of this species establish territories and build small nests in which females lay their eggs (Courtenay 1985). Them male then chases the female away and cares for the eggs until they hatch. Courtenay (1985) also found that, unlike other stickleback species, male Apeltes tend multiple nests at one time in both laboratory and natural breeding site observations. Fourspine stickleback also has the widest range of salinity tolerance of any North American species of stickleback (Holm and Hamilton 1988).

Means of Introduction: Shipping and ballast water (USEPA 2008). Denoncourt et al. (1975) were uncertain if the Susquehanna populations of this species, and that of several other additions to the drainage, represented natural occurrences or were the result of accidental introductions.

Bait shops in Alabama were found to be selling stickleback mixed in with fathead minnows at the time the specimens were collected (N. Nichols, pers. comm.).

Status: Present status in Alabama and New Jersey is unknown. Apparently established in Pennsylvania. Has become the dominant species in nearshore areas of Mission Marsh, Thunder Bay, Ontario (Stephenson and Momot 2000).

Impact of Introduction: Confined to coasts. Rapid increases of Apeltes in Thunder Bay suggests the species is displacing native stickleback species at a rapid rate (Stephenson and Momot 2000).

Remarks: In 1986, an introduced population was discovered on the Canadian side of Lake Superior in Thunder Bay; the suggested means of introduction in that case was ballast water (Holm and Hamilton 1988). In 1995, Apeltes were also taken from the Black and Nipigon Rivers (Stephenson and Momot 2000).

References: (click for full references)

Boogaard, M.A., T.D. Bills, and D.A. Johnson. 2003. Acute toxicity of TFM and a TFM/niclosamide mixture to selected species of fish, including lake sturgeon (Acipenser fulvescens) and Mudpuppies (Necturus maculosus), in Laboratory and Field Exposures. Journal of Great Lakes Research 29(Supplement 1):529-541.

Clearwater, S.J., C.W. Hickey, and M.L. Martin. 2008. Overview of potential piscicides and molluscicides for controlling aquatic pest species in New Zealand. Science & Technical Publishing, New Zealand Department of Conservation, Wellington, New Zealand.

Courtenay, S.C. 1985. Simultaneous multinesting by the fourspine stickleback, Apeltes quadracus. Canadian Field-Naturalist 99(3): 360-363.

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.

Delbeek, J.C., and D.D. Williams. 1987. Food resource partitioning between sympatric populations of brackishwater sticklebacks. The Journal of Animal Ecology, 56(3): 949-967.

GLMRIS. 2012. Appendix C: Inventory of Available Controls for Aquatic Nuisance Species of Concern, Chicago Area Waterway System. U.S. Army Corps of Engineers.

Holm, E., and J.G. Hamilton. 1988. Range extension for the fourspine stickleback, Apeltes quadracus, to Thunder Bay, Lake Superior. Canadian Field-Naturalist 102:653-656.

Marking, L.L. and T.D. Bills. 1985. Effects of contaminants on toxicity of the lampricides TFM and Bayer 73 to three species of fish. Journal of Great Lakes Research 11(2):171-178.

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.

Robins, C.R., G.C. Ray, and J. Douglass. 1986. A field guide to Atlantic Coast fishes of North America. The Peterson Guide Series, volume 32. Houghton Mifflin Company, Boston, MA.

Scott, W.B., and E.J. Crossman. 1973. Freshwater Fishes of Canada. Fisheries Research Board of Canada Bulletin 184. 966 pp.

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

Stephenson, S.A., and W.T. Momot. 2000. Threespine, Gasterosteus aculeatus, and fourspine, Apeltes quadracus, sticklebacks in the Lake Superior Basin. Canadian Field-Naturalist 114(2): 211-216.

Stiles, E.W. 1978. Vertebrates of New Jersey. Edmund W. Stiles, Somerset, NJ.

U.S. Environmental Protection Agency (USEPA). 2008. Predicting future introductions of nonindigenous species to the Great Lakes. EPA/600/R-08/066F. National Center for Environmental Assessment, Washington, DC, 138 pp. http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=190305

FishBase Summary

Author: Fuller, P., G. Jacobs, J. Larson, T.H. Makled, and A. Fusaro

Revision Date: 9/12/2019

Peer Review Date: 8/7/2013

Citation Information:
Fuller, P., G. Jacobs, J. Larson, T.H. Makled, and A. Fusaro, 2024, Apeltes quadracus (Mitchill, 1815): U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/FactSheet.aspx?SpeciesID=700, Revision Date: 9/12/2019, Peer Review Date: 8/7/2013, Access Date: 6/23/2024

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.


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Citation information: U.S. Geological Survey. [2024]. Nonindigenous Aquatic Species Database. Gainesville, Florida. Accessed [6/23/2024].

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