Hybognathus argyritis - Girard, 1856
Western Silvery Minnow
Taxonomic Status: Accepted
Related ITIS Name(s): Hybognathus argyritis Girard, 1856 (TSN 163362)
Unique Identifier: ELEMENT_GLOBAL.2.104465
Element Code: AFCJB16010
Informal Taxonomy: Animals, Vertebrates - Fishes - Bony Fishes - Minnows and Carps
Kingdom Phylum Class Order Family Genus
Animalia Craniata Actinopterygii Cypriniformes Cyprinidae Hybognathus
Genus Size: C - Small genus (6-20 species)
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Concept Reference
Concept Reference: Robins, C.R., R.M. Bailey, C.E. Bond, J.R. Brooker, E.A. Lachner, R.N. Lea, and W.B. Scott. 1991. Common and scientific names of fishes from the United States and Canada. American Fisheries Society, Special Publication 20. 183 pp.
Concept Reference Code: B91ROB01NAUS
Name Used in Concept Reference: Hybognathus argyritis
Taxonomic Comments: Formerly included in H. nuchalis (Lee et al. 1980). Pflieger (1971) presented characters that he considered diagnostic in separating H. nuchalis and H. argyritis. Schmidt (1994) noted considerable variation in these characters and indicated that the reported distinction between these two taxa should receive further scrutiny.

See Schmidt (1994) for a phylogenetic analysis of the genus Hybognathus based on morphological data.
Conservation Status

NatureServe Status

Global Status: G4
Global Status Last Reviewed: 14Feb2012
Global Status Last Changed: 28Aug1998
Ranking Methodology Used: Ranked by inspection
Rounded Global Status: G4 - Apparently Secure
Reasons: Moderately widespread in central North America from southern Canada to southern Illibnois; substantial declines in abundance in the southern half of the range; threatened by pollution, dewatering, and impoundments.
Nation: United States
National Status: N4 (28Aug1998)
Nation: Canada
National Status: N1N2 (26Dec2017)

U.S. & Canada State/Province Status
Due to latency between updates made in state, provincial or other NatureServe Network databases and when they appear on NatureServe Explorer, for state or provincial information you may wish to contact the data steward in your jurisdiction to obtain the most current data. Please refer to our Distribution Data Sources to find contact information for your jurisdiction.
United States Illinois (S2), Iowa (S1), Kansas (S2), Missouri (S2), Montana (S4), Nebraska (S5), North Dakota (SNR), South Dakota (S5), Wyoming (S2)
Canada Alberta (S1S2)

Other Statuses

Canadian Species at Risk Act (SARA) Schedule 1/Annexe 1 Status: T (05Jun2003)
Committee on the Status of Endangered Wildlife in Canada (COSEWIC): Threatened (01Nov2017)
Comments on COSEWIC: Reason for designation: This is a small-bodied minnow species that is restricted in Canada to the Milk River of southern Alberta. It is a habitat specialist found in shallow zones of turbid prairie waters with high seasonal flow variability and unstable fine sediments. It is threatened by flow management resulting from water diversions in the US and a warming and drying climate with negative impacts on habitat quantity and quality. Despite meeting criteria for Endangered, the severity of the threats is uncertain and there is no evidence of a decline in abundance since the previous assessment.

Status history: Designated Special Concern in April 1997. Status re-examined and designated Threatened in November 2001. Status re-examined and designated Endangered in April 2008. Status re-examined and designated Threatened in November 2017.

American Fisheries Society Status: Vulnerable (01Aug2008)

NatureServe Global Conservation Status Factors

Range Extent: 200,000-2,500,000 square km (about 80,000-1,000,000 square miles)
Range Extent Comments: Range includes the Missouri River basin, from southern Alberta (Houston 1998) and Montana to Missouri; Mississippi River basin from mouth of Missouri River to mouth of Ohio River; South Saskatchewan River (Hudson Bay basin), extreme southern Alberta (Page and Burr 2011).

Number of Occurrences: 81 - 300
Number of Occurrences Comments: This species is represented by a large number of occurrences (subpopulations). Generally the number of occurrences is higher in the northern portion of the range than in the southern portion of the range. Lee et al. (1980) and the Texas Natural History Collection (1996) mapped approximately 130-150 collection sites.

Population Size: 100,000 to >1,000,000 individuals
Population Size Comments: Total adult population size is unknown but apparently large (likely greater than 100,000). This species is locally common (Page and Burr 2011). For example, it is considered common in western streams of South Dakota (Doug Backlund, pers. comm., 1998). Greg Power (pers. comm., 1998) stated that this fish is still fairly common in North Dakota.

Overall Threat Impact Comments: The greatest threats are nonpoint source pollution, water depletion from irrigation, degradation of riparian areas, and mainstem impoundments impacting natural flow regimes (Northern Prairie Research Center 1995). In Missouri, the species is threatened by changes in flow regimes resulting from dam construction and channelization (Janet Sternburg, pers. comm., 1998). The degree of threat is considered moderate by the Kansas and Missouri heritage programs (Bill Busby and Janet Sternburg, pers. comm., 1998). American Fisheries Society rated this species as "Vulnerable," based on present or threatened destruction, modification, or reduction of habitat or range (Jelks et al. 2008).

Short-term Trend: Decline of 10-30%
Short-term Trend Comments: Trend over the past 10 years or three generations is uncertain, but distribution and abundance probably are slowly declining.

Long-term Trend:  
Long-term Trend Comments: This species appears to have declined drastically in the southern half of the range.

Silvery minnows were formerly common in the Missouri River in protected backwaters, but they underwent a drastic decline in abundance and distribution in recent decades and may soon disappear from Missouri (Pflieger 1997).

Status in Illinois is unknown (Glen Kruse, pers. comm., 1998).

The species is extirpated from the Kansas River in Kansas (Bill Busby, pers. comm., 1998).

In Iowa, it was historically more widely distributed; current status is unknown but probably declining (Daryl Howell, pers. comm., 1998).

Once considered abundant statewide in Nebraska, surveys over the past three decades indicate that precipitous declines have occurred in the Missouri, lower Niobrara, and Platte rivers, Nebraska (Hesse 1994, Peters and Holland 1994). Silvery minnows may have increased in abundance between 1890 and 1940, but the species declined drastically over the past three decades (see Hesse 1994). During 1976-1978 Hesse (1994) collected 40 western silvery/plains minnows from the lower Niobrara River while zero were collected in 1991. During Missouri River studies conducted during 1970-1993 the percent composition of seined western silvery/plains minnows in the channelized portion of the river was 27.1 in 1970 and zero in 1993; the percent composition of western silvery/plains minnow in the unchannelized Missouri River above and below Gavins Point Dam was less than one percent during 1983-1993 (Hesse 1994). According to Peters and Holland (1994), abundance decreased dramatically from 1987 to 1993 in the Platte River. From 1987-1989, 848 specimens were collected from 123 grids and from 1990 to1993 only four specimens from four grids (Peters and Holland 1994). During 1984-1988, Bazata et al. (1991) collected over 70,000 small fishes from 350 stream sites across Nebraska (excluding the Missouri River), only 182 western silvery minnows were collected representing 0.3% of the total composition.

In North Dakota, a long-term decline possibly has occurred, but the species is still fairly common in western drainages (Greg Power, pers. comm., 1998).

In Wyoming, the species has declined in the Little Missouri and Little Powder rivers (Patton 1997).

Other NatureServe Conservation Status Information

Inventory Needs: Better information is needed on current rangewide distribution, abundance, and populations trends (particularly in the northern half of the range).

Global Range: (200,000-2,500,000 square km (about 80,000-1,000,000 square miles)) Range includes the Missouri River basin, from southern Alberta (Houston 1998) and Montana to Missouri; Mississippi River basin from mouth of Missouri River to mouth of Ohio River; South Saskatchewan River (Hudson Bay basin), extreme southern Alberta (Page and Burr 2011).

U.S. States and Canadian Provinces

Due to latency between updates made in state, provincial or other NatureServe Network databases and when they appear on NatureServe Explorer, for state or provincial information you may wish to contact the data steward in your jurisdiction to obtain the most current data. Please refer to our Distribution Data Sources to find contact information for your jurisdiction.
Color legend for Distribution Map
Endemism: occurs (regularly, as a native taxon) in multiple nations

U.S. & Canada State/Province Distribution
United States IA, IL, KS, MO, MT, ND, NE, SD, WY
Canada AB

Range Map
No map available.

U.S. Distribution by County Help
State County Name (FIPS Code)
KS Atchison (20005)*, Brown (20013), Doniphan (20043)*, Douglas (20045)*, Johnson (20091), Leavenworth (20103), Nemaha (20131), Wyandotte (20209)
MO Adair (29001)*, Andrew (29003), Atchison (29005), Boone (29019), Buchanan (29021)*, Callaway (29027), Carroll (29033), Chariton (29041), Cole (29051), Cooper (29053), Daviess (29061)*, Franklin (29071), Gasconade (29073), Gentry (29075)*, Grundy (29079)*, Harrison (29081), Holt (29087), Howard (29089), Jackson (29095), Lafayette (29107), Livingston (29117)*, Mercer (29129)*, Miller (29131)*, Moniteau (29135), Montgomery (29139), Morgan (29141)*, Osage (29151), Perry (29157)*, Platte (29165), Putnam (29171)*, Ray (29177), Saline (29195), Scott (29201)*, St. Charles (29183), St. Louis (29189), Warren (29219), Worth (29227)
NE Boyd (31015), Buffalo (31019), Butler (31023), Colfax (31037), Cuming (31039), Dodge (31053), Douglas (31055), Dundy (31057), Franklin (31061), Hall (31079)*, Hitchcock (31087), Holt (31089), Howard (31093), Kearney (31099)*, Loup (31115), Morrill (31123), Nance (31125), Otoe (31131), Red Willow (31145), Sheridan (31161), Sherman (31163), Webster (31181)
WY Big Horn (56003), Campbell (56005), Crook (56011), Hot Springs (56017), Johnson (56019), Park (56029)*, Sheridan (56033), Washakie (56043)
* Extirpated/possibly extirpated
U.S. Distribution by Watershed Help
Watershed Region Help Watershed Name (Watershed Code)
07 Peruque-Piasa (07110009)+, Cahokia-Joachim (07140101)+, Meramec (07140102)*, Upper Mississippi-Cape Girardeau (07140105)+, Lower Kaskaskia (07140204)*
10 Teton (10030205), Bullwhacker-Dog (10040101), Fort Peck Reservoir (10040104), Big Dry (10040105), Little Dry (10040106), Middle Musselshell (10040202), Lower Musselshell (10040205), Middle Milk (10050004), Big Sandy (10050005), Peoples (10050009), Cottonwood (10050010), Whitewater (10050011), Lower Milk (10050012), Frenchman (10050013), Beaver (10050014), Rock (10050015), Porcupine (10050016), Prarie Elk-Wolf (10060001), Redwater (10060002), Poplar (10060003), West Fork Poplar (10060004), Charlie-Little Muddy (10060005), Big Muddy (10060006), Brush Lake closed basin (10060007), Upper Yellowstone-Pompeys Pillar (10070007), Upper Bighorn (10080007)+, Greybull (10080009)+*, Big Horn Lake (10080010)+, Shoshone (10080014)+, Lower Bighorn (10080015), Little Bighorn (10080016), Upper Tongue (10090101), Lower Tongue (10090102), Upper Powder (10090202)+, Clear (10090206)+, Middle Powder (10090207)+, Little Powder (10090208)+, Lower Powder (10090209), Mizpah (10090210), Lower Yellowstone-Sunday (10100001), Big Porcupine (10100002), Rosebud (10100003), Lower Yellowstone (10100004), O'fallon (10100005), Lake Sakakawea (10110101), Upper Little Missouri (10110201)+, Boxelder (10110202), Middle Little Missouri (10110203), Beaver (10110204), Lower Little Missouri (10110205), Upper Belle Fourche (10120201)+*, Lower Belle Fourche (10120202)+, Upper Lake Oahe (10130102), Upper Heart (10130202), Lower Heart (10130203), Upper Cannonball (10130204), Lower Cannonball (10130206), Lower Moreau (10130306), Fort Randall Reservoir (10140101), Bad (10140102), Middle White (10140202), Lower White (10140204), Ponca (10150001)+, Upper Niobrara (10150003)+, Keya Paha (10150006)+, Lewis and Clark Lake (10170101), Lower Big Sioux (10170203), Rock (10170204)*, Middle North Platte-Scotts Bluff (10180009)+, Middle Platte-Buffalo (10200101)+, Middle Platte-Prairie (10200103)+, Lower Platte-Shell (10200201)+, Lower Platte (10200202), Lower Middle Loup (10210003)+, South Loup (10210004)+, Lower North Loup (10210007)+, Loup (10210009)+, Upper Elkhorn (10220001)+, Lower Elkhorn (10220003)+, Blackbird-Soldier (10230001), Little Sioux (10230003), Big Papillion-Mosquito (10230006), Keg-Weeping Water (10240001)+, Nishnabotna (10240004)+, Tarkio-Wolf (10240005)+, South Fork Big Nemaha (10240007)+, Big Nemaha (10240008), Independence-Sugar (10240011)+, Platte (10240012)+*, North Fork Republican (10250002)+*, Upper Republican (10250004)+, Middle Republican (10250016)+, Lower Republican (10250017)*, Upper Kansas (10270101)*, Middle Kansas (10270102)*, Delaware (10270103), Lower Kansas (10270104)+, Upper Grand (10280101)+, Thompson (10280102)+*, Lower Grand (10280103)+*, Upper Chariton (10280201)+*, Lower Chariton (10280202)+*, Little Chariton (10280203)+, Lower Osage (10290111)+, Lower Gasconade (10290203)+, Lower Missouri-Crooked (10300101)+, Lower Missouri-Moreau (10300102)+, Lamine (10300103)+, Blackwater (10300104)+, Lower Missouri (10300200)+
+ Natural heritage record(s) exist for this watershed
* Extirpated/possibly extirpated
U.S. Distribution by Watershed (based on multiple information sources) Help
Ecology & Life History
Basic Description: A small-medium minnow 3-5 inches long (western silvery minnow).
Habitat Type: Freshwater
Non-Migrant: N
Locally Migrant: N
Long Distance Migrant: N
Riverine Habitat(s): BIG RIVER, Low gradient, MEDIUM RIVER, Pool
Habitat Comments: Habitat includes backwaters and pools of large, silty, small to large plains rivers; usually over sand or mud (Lee et al. 1980, Page and Burr 2011). Probably eggs are scattered on silt substrate in quiet water.
Food Comments: Probably ingests mud and bottom ooze containing algae and organic debris.
Length: 13 centimeters
Economic Attributes Not yet assessed
Management Summary Not yet assessed
Population/Occurrence Delineation
Group Name: Medium Cyprinids

Use Class: Not applicable
Minimum Criteria for an Occurrence: Occurrences are based on evidence of historical presence, or current and likely recurring presence, at a given location. Such evidence minimally includes collection or reliable observation and documentation of one or more individuals (including eggs and larvae) in appropriate habitat.
Separation Barriers: Dam lacking a suitable fishway; high waterfall; upland habitat.
Separation Distance for Unsuitable Habitat: 15 km
Separation Distance for Suitable Habitat: 15 km
Separation Justification: Data on dispersal and other movements generally are not available. In some species, individuals may migrate variable distances between spawning areas and nonspawning habitats.

Separation distances (in aquatic kilometers) for cyprinids are arbitrary but reflect the presumption that movements and appropriate separation distances generally should increase with fish size. Hence small, medium, and large cyprinids, respectively, have increasingly large separation distances. Separation distance reflects the likely low probability that two occupied locations separated by less than many kilometers of aquatic habitat would represent truly independent populations over the long term.

Because of the difficulty in defining suitable versus unsuitable habitat, especially with respect to dispersal, and to simplify the delineation of occurrences, a single separation distance is used regardless of habitat quality.

Occupied locations that are separated by a gap of 15 km or more of any aquatic habitat that is not known to be occupied represent different occurrences. However, it is important to evaluate seasonal changes in habitat to ensure that an occupied habitat occurrence for a particular population does not artificially separate spawning areas and nonspawning areas as different occurrences simply because there have been no collections/observations in an intervening area that may exceed the separation distance.

Date: 21Sep2004
Author: Hammerson, G.
Population/Occurrence Viability
U.S. Invasive Species Impact Rank (I-Rank) Not yet assessed
NatureServe Conservation Status Factors Edition Date: 14Feb2012
NatureServe Conservation Status Factors Author: Hammerson, G., and M. K. Clausen
Element Ecology & Life History Edition Date: 14Feb2012
Element Ecology & Life History Author(s): Hammerson, G.

Zoological data developed by NatureServe and its network of natural heritage programs (see Local Programs) and other contributors and cooperators (see Sources).

  • Andersen, M.D. and B. Heidel. 2011. HUC-based species range maps. Prepared by Wyoming Natural Diversity Database for use in the pilot WISDOM application operational from inception to yet-to-be-determined date of update of tool.

  • Baxter, G.T. and M.D. Stone. 1995. Fishes of Wyoming. Wyoming Game and Fish Department, Cheyenne, Wyoming. 290 pp.

  • Bazata, K. 1991. Nebraska stream classification study. Lincoln, Nebraska Department of Environmental Quality.



  • Hesse, L. W. 1994. The status of Nebraska fishes in the Missouri River, 5. selected chubs and minnows (Cyprinidae): sicklefin chub (Macrhybopsis meeki), sturgeon chub (M. gelida), silver chub (M. storeriana), speckled chub (M. aestivalis), flathead chub (Platygobio gracilis), plains minnow (Hybognathus placitus), and western silvery minnow (H.argyritis). Transactions of the Nebraska Academy of Sciences 21:99-108.

  • Houston, J. 1998. Status of the western silvery minnow, Hybognathus argyritis, in Canada. Canadian Field-Naturalist 112:147-153.

  • Jelks, H. L., S. J. Walsh, N. M. Burkhead, S. Contreras-Balderas, E. Díaz-Pardo, D. A. Hendrickson, J. Lyons, N. E. Mandrak, F. McCormick, J. S. Nelson, S. P. Platania, B. A. Porter, C. B. Renaud, J. Jacobo Schmitter-Soto, E. B. Taylor, and M.L. Warren, Jr. 2008. Conservation status of imperiled North American freshwater and diadromous fishes. Fisheries 33(8):372-407.

  • Klutho, M. A. 1983. Seasonal, daily, and spatial variation of shoreline fishes in the Mississippi River at Grand Tower, Illinois. Master Thesis, Southern Illinois University, Carbondale.

  • Nelson, J. S., E. J. Crossman, H. Espinosa-Perez, L. T. Findley, C. R. Gilbert, R. N. Lea, and J. D. Williams. 2004. Common and scientific names of fishes from the United States, Canada, and Mexico. American Fisheries Society, Special Publication 29, Bethesda, Maryland. 386 pp.

  • Northern Prairie Wildlife Research Center. 1995. North Dakota's federally listed endangered, threatened, and candidate species: plains minnow (Hybognathus placitus). Available online: http://www.npwrc.usgs.gov/resource/distr/others/nddanger/spe cies/hyboplac.htm.


  • Page, L. M., H. Espinosa-Pérez, L. T. Findley, C. R. Gilbert, R. N. Lea, N. E. Mandrak, R. L. Mayden, and J. S. Nelson. 2013. Common and scientific names of fishes from the United States, Canada, and Mexico. Seventh edition. American Fisheries Society, Special Publication 34, Bethesda, Maryland.

  • Page, L. M., and B. M. Burr. 1991. A field guide to freshwater fishes: North America north of Mexico. Houghton Mifflin Company, Boston, Massachusetts. 432 pp.

  • Page, L. M., and B. M. Burr. 2011. Peterson field guide to freshwater fishes of North America north of Mexico. Second edition. Houghton Mifflin Harcourt, Boston. xix + 663 pp.

  • Patton, T. M. 1997. Distribution and status of fishes in the Missouri River drainage in Wyoming: Implications for identifying conservation areas. Ph.D. dissertation, University of Wyoming, Laramie, Wyoming.

  • Peters, E. J., and R. S. Holland. 1994. Biological and economic analyses of the fish communities in the Platte River: modifications and tests of habitat suitability criteria for fishes of the Platte River. Federal Aid in Fish Restoration Project No. F-78-R Study III: Job III-2. University of Nebraska, Lincoln.

  • Pflieger, W. L. 1971. A distributional study of Missouri fishes. University of Kansas Museum of Natural History Miscellaneous Publication 20:225-570.

  • Pflieger, W. L. 1997a. Fishes of Missouri. Revised Edition. Missouri Department of Conservation, Jefferson City, Missouri.

  • Pflieger, W. L. and T. B. Grace. 1987. Changes in the fish fauna of the lower Missouri River, 1940-1983. Pages 166-181 in W. J. Matthews and D. C Heins (editors). Community and Evolutionary Ecology of North American Stream Fishes. University of Oklahoma Press, Norman, Oklahoma.

  • Robins, C.R., R.M. Bailey, C.E. Bond, J.R. Brooker, E.A. Lachner, R.N. Lea, and W.B. Scott. 1991. Common and scientific names of fishes from the United States and Canada. American Fisheries Society, Special Publication 20. 183 pp.

  • Schmidt, T. R. 1994. Phylogenetic relationships of the genus Hybognathus (Teleostei: Cyprinidae). Copeia 1994:622-630.

  • Texas Natural History Collection. 1996. Sept. 9 last update. Index to North American freshwater fishes (fish images, maps, and information). Online. Available: http://www.utexas.edu/depts/tnhc/na/naindex.html.

References for Watershed Distribution Map
  • Baxter, G. T., and J. R. Simon. 1970. Wyoming fishes. Wyoming Game and Fish Department, Cheyenne, Wyoming, 168 pp.

  • Cross, F. B., and J. T. Collins. 1995. Fishes in Kansas. Second Edition, revised. University of Kansas Museum of Natural History. xvii + 315 pp.

  • Harlan, J. R., E. B. Speaker, and J. Mayhew. 1987. Iowa fish and fishing. Iowa Conservation Commission, Des Moines, Iowa. 323 pp.

  • Holton, G. D., and H. E. Johnson. 1996. A field guide to Montana fishes. 2nd edition. Montana Fish, Wildlife and Parks, Montana State Parks and wildlife Interpretive Association, Helena, Montana. 104 pp.

  • 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, North Carolina. i-x + 854 pp.

  • Pflieger, W. L. 1975. The fishes of Missouri. Missouri Department of Conservation. Columbia, Missouri. viii + 343 pp.

  • Smith, P. W. 1979. The fishes of Illinois. University of Illinois Press, Urbana. 314 pp.

  • State Natural Heritage Data Centers. 1996a. Aggregated element occurrence data from all U.S. state natural heritage programs, including the Tennessee Valley Authority, Navajo Nation and the District of Columbia. Science Division, The Nature Conservancy.

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