|Scientific Name:||Catostomus snyderi|
|Species Authority:||Gilbert, 1898|
|Taxonomic Notes:||This species presumably is closely related to Catostomus macrocheilus of the Columbia River drainage and to C. occidentalis of the Sacramento drainage (Moyle et al. 1989). Catostomus snyderi shares a gene pool with Catostomus rimiculus, Chasmistes brevirostris, and Deltistes luxatus as a result of recent hybridization events, although the species largely maintain their morphological identities (Moyle 2002). Catostomus snyderi hybridizes with Deltistes luxatus and Chasmistes brevirostris (both endangered); strong introgression involving C. brevirostris has been noted in the Clear Lake and Lost River systems, Oregon and California (Andreasen 1975). Catostomus snyderi has hybridized with Deltistes luxatus and Chasmistes brevirostris in Upper Klamath Lake, but no introgression has occurred and distinct species still are present (Moyle et al. 1989). Catostomus snyderi in the Sprague River (a tributary to upper Klamath Lake in Oregon) is genetically distinct from all other suckers; taxonomic status needs further study (Tranah 2001).|
|Red List Category & Criteria:||Near Threatened ver 3.1|
|Reviewer(s):||Smith, K. & Darwall, W.R.T.|
|Facilitator/Compiler(s):||Hammerson, G.A. & Ormes, M.|
Listed as Near Threatened in view of the small range (extent of occurrence is less than 20,000 km2), limited number of locations (possibly fewer than 10), and declining population over the past three generations (but now possibly increasing). Hence, the species possibly but not clearly qualifies as Vulnerable.
|Previously published Red List assessments:|
|Range Description:||Range includes the Klamath River and Lost River-Clear Lake systems of Oregon and California (Moyle 2002). The species is known from Upper Klamath Lake, the entire Sprague River, the lower 20 kilometers of the Sycan River, the lower Williamson River, the Williamson River above Klamath Marsh, and the Clear Lake-Lost River system (Andreasen 1975). In California, the species occurs mainly in the Lost River drainage and in the Klamath River above Iron Gate Reservoir (Moyle et al. 1989, Moyle 2002). It occurs in the Klamath River below Klamath Falls but exists mostly above the falls (Moyle et al. 1989). Core populations are in Oregon.|
Native:United States (California, Oregon)
|Range Map:||Click here to open the map viewer and explore range.|
|Population:||This species is represented by several distinct occurrences.|
Total adult population size is unknown but presumably exceeds 10,000. Page and Burr (2011) described this species as "common." Ellsworth et al. (2011) noted that more than 5,000 individuals have been PIT-tagged since 2000.
Area of occupancy, number of subpopulations, abundance, and habitat quality have surely declined, but the degree of decline is uncertain. This species is possibly extirpated from California (Moyle 2002).
Distribution and abundance have probably declined over the past three generations (three generations is probably at least 30 years), but the degree of decline is unknown. Moyle (2002) stated that this species may be on its way to becoming a threatened species, especially in California, which is on the edge of the limited range. He stated that Oregon populations are in relatively good shape. Ellsworth et al. (2011) reported that recruitment to the adult population has occurred in a number of years since 2001.
|Current Population Trend:||Decreasing|
|Habitat and Ecology:||Habitat includes rocky pools and runs of creeks and small rivers, lakes, and reservoirs (Page and Burr 2011). Historically, most large adults probably inhabited lakes (especially deep water), and juveniles lived in streams or in lake shallows (Moyle 2002). The species is largely absent from highly eutrophic Upper and Lower Klamath Lakes, except where inflowing streams improve water quality (Scoppettone and Vinyard 1991, Moyle 2002). Today these suckers occur mainly in large streams with good water quality. Streams that support C. snyderi populations rarely exceed 25°C (Moyle 2002). Spawning occurs in upstream tributaries.|
|Movement patterns:||Not a Migrant|
This species occurs in an environment that has been highly modified by dams, diversions, grazing, pollution, and introductions of non-native predatory fishes (e.g., Sacramento perch and yellow perch) (Moyle 2002). Its ability to use fish ladders has somewhat reduced the impact of dams (Scoppettone and Vinyard 1991). Hybridization with other suckers may be a threat in some areas.
Jelks et al. (2008) listed this species as "threatened," based on present or threatened destruction, modification, or reduction of habitat or range; other natural or anthropogenic factors that affect a taxon's existence, including impacts of nonindigenous organisms, hybridization, competition, and/or predation; and a narrowly restricted range.
Removal of a dam on one tributary resulted in a substantial increase in the number of individuals that migrated upstream past the dam site (Ellsworth et al. 2011).
|Conservation Actions:||This species would benefit from habitat restoration, improved habitat protection and management, and from better information on distribution, abundance, population trend, life history, and threats.|
|Citation:||NatureServe. 2014. Catostomus snyderi. The IUCN Red List of Threatened Species 2014: e.T4053A2933050.Downloaded on 28 October 2016.|