Pantosteus discobolus

(Cope, 1871)

Bluehead Sucker

G4Apparently Secure (G4G5) Found in 1 roadless area NatureServe Explorer →
G4Apparently SecureGlobal Rank
UnknownThreat Impact
Identity
Unique IDELEMENT_GLOBAL.2.1167686
Element CodeAFCJC02350
Record TypeSPECIES
ClassificationSpecies
Classification StatusStandard
Name CategoryVertebrate Animal
Endemicendemic to a single nation
KingdomAnimalia
PhylumCraniata
ClassActinopterygii
OrderCypriniformes
FamilyCatostomidae
GenusPantosteus
Synonyms
Catostomus discobolusCope, 1871
Concept Reference
Unmack, P.J., T.E. Dowling, N.J. Laitinen, C.L. Secor, R.L. Mayden, D.K. Shiozawa, and G.R. Smith. 2014. Influence of introgression and geological processes on phylogenetic relationships of western North American mountain suckers (Pantosteus, Catostomidae). PLoS One 9(3), p.e90061.
Taxonomic Comments
This is a narrow concept of Pantosteus discobolus that is recognized by the American Fisheries Society (Page et al. 2023). Divergent mtDNA and morphological differences support the recognition of virescens as distinct from discobolus (Chen and Mayden 2012, Unmack et al. 2014, Bangs et al. 2018). As circumscribed here, Pantosteus discobolus occurs in the larger rivers in the Upper Colorado Basin and Pantosteus virescens occurs in the Bonneville and Upper Snake river basins.

Unmack et al. (2014) elevated the subgenus Pantosteus to generic status based on a comparison of molecular, morphological, and paleontological data. Page et al. (2023) accepted this elevation, but others (e.g., Bangs et al. 2018) retain as a subgenus pending additional morphological and molecular analyses.

Pantosteus discobolus, P. virescens, P. clarkii, P. santaanae and P. plebeius form a clade diagnosed by mtDNA as well as morphological traits (Smith et al. 2013).
Conservation Status
Rank Method Rank calculation - Biotics v2
Review Date2024-12-18
Change Date2024-12-18
Edition Date2024-12-18
Edition AuthorsGundy, R. L. (2024)
Threat ImpactUnknown
Range Extent200,000-2,500,000 square km (about 80,000-1,000,000 square miles)
Number of Occurrences81 - 300
Rank Reasons
This species is widespread in larger rivers in the Upper Colorado River Basin, Lower Colorado River Basin, and Grand Canyon. The impacts of dams, anthropogenic water use, and invasive fishes are not well-understood. The population has suffered historical declines and range contraction, but the population is presumed to be relatively stable.
Range Extent Comments
This species occurs in the larger rivers in the Upper Colorado drainage (Grand Canyon and north) in Arizona, New Mexico, Utah, Colorado, and Wyoming, USA (Page and Burr 2011, Smith et al. 2013, Unmack et al. 2014, Bangs et al. 2018). Using Global Biodiversity Information Facility (GBIF) (2024) records, range extent is estimated to be 299,414 km².
Occurrences Comments
This species is represented by a large number of occurrences (subpopulations).
Threat Impact Comments
Riverine habitat has been fragmented and degraded by construction of passage barriers (e.g., diversion dams and reservoirs), diversion of water and associated changes in flow, stream channelization, and general deterioration of riparian corridors (Bezzerides and Bestgen 2002, Weitzel 2002, Ptacek et al. 2005). Droughts are causing increasing water temperatures which can reduce egg survival (Cadmus et al. 2022). Introduced, and now widely established, non-native species pose a threat through predation and competition (Bezzerides and Bestgen 2002, Weitzel 2002, Ptacek et al. 2005).
Ecology & Habitat
Other Nations (1)
United StatesNNR
ProvinceRankNative
Navajo NationS5Yes
New MexicoS2Yes
WyomingS3Yes
UtahS3Yes
ColoradoS4Yes
NevadaS1Yes
ArizonaS3Yes
Threat Assessments
ThreatScopeSeverityTiming
7 - Natural system modificationsLarge (31-70%)UnknownHigh (continuing)
7.2 - Dams & water management/useLarge (31-70%)UnknownHigh (continuing)
8 - Invasive & other problematic species, genes & diseasesLarge - restrictedUnknownHigh (continuing)
8.1 - Invasive non-native/alien species/diseasesLarge - restrictedUnknownHigh (continuing)
11 - Climate change & severe weatherPervasive (71-100%)UnknownHigh (continuing)
11.2 - DroughtsPervasive (71-100%)UnknownHigh (continuing)

Roadless Areas (1)
Utah (1)
AreaForestAcres
Happy ValleyDixie National Forest14,458
References (10)
  1. Bangs, M.R., M.R. Douglas, S.M. Mussmann, and M.E. Douglas. 2018. Unraveling historical introgression and resolving phylogenetic discord within Catostomus (Osteichthys: Catostomidae). BMC Evolutionary Biology 18(1): 86.
  2. Bezzerides, N., and K. R. Bestgen. 2002. Status review of roundtail chub <i>Gila robusta</i>, flannelmouth sucker <i>Catostomus latipinnis</i>, and bluehead sucker <i>Catostomus discobolus</i> in the Colorado River Basin. Colorado State University, Fort Collins, Colorado.
  3. Cadmus, P., T. B. Riepe, M. Bolerjack. 2022. Water pollution studies, 2022 progress report. Colorado Parks and Wildlife, Aquatic Research Section, Fort Collins, Colorado. 67 pp.
  4. Chen, W.J. and R.L. Mayden. 2012. Phylogeny of suckers (Teleostei: Cypriniformes: Catostomidae): further evidence of relationships provided by the singlecopy nuclear gene IRBP2. Zootaxa 3586:195–210.
  5. 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.
  6. 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.
  7. Ptacek, J. A., D. E. Rees, and W. J. Miller. 2005. Bluehead sucker (<i>Catostomus discobolus</i>): a technical conservation assessment. USDA Forest Service, Rocky Mountain Region.
  8. Smith, G.R., J.D. Stewart and N.E. Carpenter. 2013. Fossil and recent mountain suckers, <i>Pantosteus</i>, and significance of introgression in catostomin fishes of Western United States. Occasional Papers of the Museum of Zoology University of Michigan No. 743: 1-59.
  9. Unmack, P.J., T.E. Dowling, N.J. Laitinen, C.L. Secor, R.L. Mayden, D.K. Shiozawa, and G.R. Smith. 2014. Influence of introgression and geological processes on phylogenetic relationships of western North American mountain suckers (<i>Pantosteus</i>, Catostomidae). PLoS One 9(3), p.e90061.
  10. Weitzel, D. L. 2002. Conservation and status assessments for the bluehead sucker (<i>Catostomus discobolus</i>), flannelmouth sucker (<i>Catostomus latipinnis</i>), roundtail chub (<i>Gila robusta</i>), and leatherside chub (<i>Gila copei</i>): rare fishes west of the Continental Divide, Wyoming. Wyoming Game and Fish Department, Cheyenne. 51 pp.