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Home/Species/ Lahontan Redside

Richardsonius egregius

(Girard, 1858)

Lahontan Redside

G5Secure Found in 13 roadless areas NatureServe Explorer →
G5SecureGlobal Rank
Least concernIUCN
LowThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.106214
Element CodeAFCJB39020
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVertebrate Animal
IUCNLeast concern
Endemicendemic to a single nation
KingdomAnimalia
PhylumCraniata
ClassActinopterygii
OrderCypriniformes
FamilyLeuciscidae
GenusRichardsonius
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.
Taxonomic Comments
See Gold and Li (1994) for cytosystematic evidence that the genus Richardsonius belongs in the western clade of phoxinin cyprinids.

Hybridizes with Gila bicolor and Rhinichthys osculus (Lee et al. 1980).
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2025-04-09
Change Date1999-01-12
Edition Date2025-04-09
Edition AuthorsGundy, R. L. (2025)
Threat ImpactLow
Range Extent20,000-200,000 square km (about 8000-80,000 square miles)
Number of Occurrences81 - 300
Rank Reasons
This species is abundant within the range in the western United States. There are no rangewide threats known and no reports of decline.
Range Extent Comments
This species is found in the Lahontan and other interior basins in northern and western Nevada, east-central California, and extreme southeastern Oregon in the United States (Lee et al. 1980, Page and Burr 1991, Houston et al. 2010, Nelson 2023, GBIF 2025). It is found in the the Walker, Carson, Truckee, Susan, Quinn, Reese, and Humboldt river systems, and Walker, Tahoe, and Pyramid lakes (Lee et al. 1980, Page and Burr 1991). Using Global Biodiversity Information Facility (GBIF) (2025) records, range extent is estimated to be 173,988 km² (RARECAT 2025).

There is also a non-native population in the upper Sacramento River system, California (Brown and Moyle 2005). This non-native population is not included in this assessment.
Occurrences Comments
This species is represented by a large number of subpopulations and locations.
Threat Impact Comments
Localized threats may exist, but on a range-wide scale no major threats are known (Moyle et al. 2011, Moyle et al. 2013, Oregon Biodiversity Information Center 2019, Dauwalter et al. 2023, Nelson 2023).
Ecology & Habitat

Habitat

Deep, quiet waters as well as swift currents of mountain tributaries; congregates around submerged logs, wharves, and other sheltered places (Lee et al. 1980). All types of stream habitats; most common in pools and slow runs; margins of lakes (Page and Burr 1991). Lake Tahoe: littoral zone, close to surface, except when water temperature is less than 10 C.

Lake Tahoe populations spawn either at the downstream end of pools in sand and gravel areas of tributaries, or over gravel and small rock substrate along the lake shoreline (Moyle 1976).

Ecology

Congregates in large schools in lakes.

Reproduction

Generally matures in second or third year. In Nevada, spawns in May and June. Lake Tahoe: spawns in June and July. (Lee et al. 1980).
Other Nations (1)
United StatesN5
ProvinceRankNative
CaliforniaSNRYes
NevadaS5Yes
OregonS2Yes
Threat Assessments
ThreatScopeSeverityTiming
No known threats———

—

Roadless Areas (13)
California (10)
AreaForestAcres
Caples CreekEldorado National Forest17,854
Carson - IcebergStanislaus National Forest56,430
Castle PeakTahoe National Forest14,974
EbbettsHumboldt-Toiyabe National Forest255
Granite ChiefTahoe National Forest6,546
Hall Natural AreaInyo National Forest5,236
North Fork American RiverTahoe National Forest38,495
PyramidEldorado National Forest24,347
Raymond PeakStanislaus National Forest3,646
Raymond PeakEldorado National Forest2,518
Nevada (3)
AreaForestAcres
Chineese Camp (NV)Humboldt-Toiyabe National Forest15,207
GrantsvilleHumboldt-Toiyabe National Forest6,156
Pine Grove SouthHumboldt-Toiyabe National Forest88,945
References (23)
  1. Brown, L. R., and P. B. Moyle. 2005. Native fishes of the Sacramento–San Joaquin Drainage, California: a history of decline. American Fisheries Society Symposium 45: 75–98.
  2. Dauwalter, D. C., E. Miskow, and C. Crookshanks. 2023. Spatial conservation assessment for native fishes in the Lahontan and Central Nevada Basins, USA. Water 15: 1087. doi: 10.3390/w15061087
  3. Global Biodiversity Information Facility (GBIF). 2025. Global Biodiversity Information Facility (GBIF) data portal. Online. Available: https://www.gbif.org/ (accessed 2025).
  4. Gold, J. R., and Y. C. Li. 1994. Cytosystematic evidence that the genus <i>Richardsonius</i> belongs in the western clade of phoxinin cyprinids. Copeia 1994:815-818.
  5. Houston, D. D., D. K. Shiozawa, and B. R. Riddle. 2010. Phylogenetic relationships of the western North American cyprinid genus <i>Richardsonius</i>, with an overview of phylogeographic structure. Molecular Phylogenetics and Evolution 55: 259–273.
  6. La Rivers, I. 1962. Fishes and Fisheries of Nevada. Nevada State Fish and Game Commission, Carson City, Nevada. 782 pp.
  7. 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.
  8. Master, L. L. 1996. Synoptic national assessment of comparative risks to biological diversity and landscape types: species distributions. Summary Progress Report submitted to Environmental Protection Agency. The Nature Conservancy, Arlington, Virginia. 60 pp.
  9. Master, L. L. and A. L. Stock. 1998. Synoptic national assessment of comparative risks to biological diversity and landscape types: species distributions. Summary Report submitted to Environmental Protection Agency. The Nature Conservancy, Arlington, VA. 36 pp.
  10. Moyle, P. B. 1976a. Inland fishes of California. University of California Press, Berkeley, California. 405 pp.
  11. Moyle, P. B. 2002. Inland fishes of California. Revised and expanded. University of California Press, Berkeley. xv + 502 pp.
  12. Moyle, P. B., J. D. Kiernan, P. K. Crain, and R. M. Quiñones. 2013. Climate change vulnerability of native and alien freshwater fishes of California: a systematic assessment approach. PLoS ONE 8(5):e63883. doi: 10.1371/journal.pone.0063883
  13. Moyle, P. B., J. V. E. Katz, and R. M. Quiñones. 2011. Rapid decline of California's native inland fishes: a status assessment. Biological Conservation 144:2414-2423. doi:10.1016/j.biocon.2011.06.002
  14. 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.
  15. Nelson, M. 2023. Oregon state rank assessment for Lahontan redside (<i>Richardsonius egregius</i>). Oregon Biodiversity Information Center. Institute for Natural Resources, Portland State University, Portland, OR.
  16. Oregon Biodiversity Information Center. 2019. Rare, threatened and endangered species of Oregon. Institute for Natural Resources, Portland State University, Portland, Oregon. 133 pp. <br/>
  17. 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.
  18. 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.
  19. 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.
  20. Page, L. M., K. E. Bemis, T. E. Dowling, H.S. Espinosa-Pérez, L.T. Findley, C. R. Gilbert, K. E. Hartel, R. N. Lea, N. E. Mandrak, M. A. Neigbors, J. J. Schmitter-Soto, and H. J. Walker, Jr. 2023. Common and scientific names of fishes from the United States, Canada, and Mexico. Eighth edition. American Fisheries Society (AFS), Special Publication 37, Bethesda, Maryland, 439 pp.
  21. <p>NatureServe's Rapid Analysis of Rarity and Endangerment Conservation Assessment Tool (RARECAT). 2025. Version: 2.1.1 (released April 04, 2025).</p>
  22. 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.
  23. Sigler, W. F., and J. W. Sigler. 1987. Fishes of the Great Basin: a natural history. University of Nevada Press, Reno, Nevada. xvi + 425 pp.