occurs (regularly, as a native taxon) in multiple nations
Regularity: Regularly occurring
Type of Residency: Year-round
Regularity: Regularly occurring
Type of Residency: Year-round
Global Range: (20,000-2,500,000 square km (about 8000-1,000,000 square miles)) Range is unclear due to taxonomic uncertainty with the Pacific Drainage members of this genus. In the broadest view, it once ranged from southern British Columbia south to northernmost Baja California, eastward to western Wyoming, eastern Arizona and Chihuahua (Mexico), but this distribution probably includes records for other species (Taylor, 1981; Nedeau et al., 2005) such as Anodonta nuttalliana. Taylor (1987) lists the species in 4 inch or greater depth pools in a spring complex above the North Fork of the East Fork of the Black River, Apache Co., Arizona. Clark and Hovingh (1993) state that "As presently understood this species occurs in California, Nevada, Utah, and Arizona." and that the closely related Anodonta nuttalliana occurs in Oregon, Washington, and British Columbia. Preliminary analysis (K. Mock, Utah State University, pers. comm.) indicates Utah Anodonta are distinct from Anodonta oregonensis of the Pacific northwest and should tentatively be assigned to Anodonta californiensis pending future taxonomic work. Presently, Frest and Johannes (1995) report the range has been reduced and extant populations are currently found in the following areas: the Middle Snake River in Idaho; the Fall and Pit rivers in Shasta County, California; the Okanogan river in Chelan County, Washington; and Roosevelt and Curlew lakes in Ferry County, Washington. No living specimens were found in the Willamette and lower Columbia rivers in searches by Frest and Johannes conducted from 1988-1990. Taylor (1981) reports that most of the natural populations in California have been eradicated and it is probably extinct in most of the Central Valley of southern California. In Utah the only recent records are in two widely-spaced locations, Big Creek and Reddin Spring pond, but it may still be extant in the Raft River and portions of the Bear River drainage (Clark and Hovingh, 1993). It is extirpated from Utah Lake. Hovingh (2004) found it widely distributed in the Humboldt River drainage (Lahontan Basin) in northern Nevada, in the bonneville Basin in Utah, Nevada, and Wyoming, and in the Malheur and Warner Basins in Oregon. Mock et al. (2005) list six sites in the Bonneville basin of Utah tentatively assigned to this species.
Catalog Number: USNM 86393
Collection: Smithsonian Institution, National Museum of Natural History, Department of Invertebrate Zoology
Locality: Colorado River, California, United States
Habitat and Ecology
Habitat Type: Freshwater
Comments: This is a low elevation species that is found in both lakes and lake-like stream environments (Frest and Johannes, 1995).
Non-Migrant: No. All populations of this species make significant seasonal migrations.
Locally Migrant: No. No populations of this species make local extended movements (generally less than 200 km) at particular times of the year (e.g., to breeding or wintering grounds, to hibernation sites).
Locally Migrant: No. No populations of this species make annual migrations of over 200 km.
Number of Occurrences
Note: For many non-migratory species, occurrences are roughly equivalent to populations.
Estimated Number of Occurrences: 21 - 300
Comments: Number of occurrences (>20 but <100) uncertain. Beetle (1989) and Cvancara (2005) list the Bear River in Uinta Co., Wyoming. In Utah, 2 to 6 sites known from Utah, Millard, Rich, Tooele, and Box Elder Cos. (Oliver and Bosworth, 1999); with recent occurrences (tentatively A. californiensis) in Bear River, Redden Spring, Pruess Lake, Piute Reservoir, Otter Creek Reservoir, and Burriston Ponds (Mock et al., 2004). Mock et al. (2004) cite it (tentative A. californiensis) from the Black River, Apache, Arizona. Frest and Johannes (1995) report range reduced and extant in: Middle Snake River in Idaho; Fall and Pit Rivers in Shasta Co., California; Okanogan River in Chelan Co., Washington; and Roosevelt and Curlew Lakes in Ferry Co., Washington. No living specimens in the Willamette and lower Columbia rivers in searches by Frest and Johannes 1988-1990. Frest and Johannes (2000) list it as common locally in the Snake River and major tributaries. Taylor (1981) reports most California populations eradicated and likely extinct in most of the Central Valley. Currently in California, it is in the S Fork Eel, River, Lake Del Valle, Suisun Marsh, W Fork Walker River, Big Lake, Fall River, Tule River, Hat Creek, Russian River, Clear Lake, Pit and S Fork Pit River, Sacremento River, Donner Lake, Scott River, Lost River, Pajaro River, San Joaquin River, Dye Creek, Shasta River, Bridgeport Reservoir, Salton Sea, and Susan River (Howard, 2010). It was once throughout 6 major drainages in Arizona (incl. Lake Mead, Grand Canyon, Lower Colorado-Marble Canyon, Lower Lake Powell), but today only parts of the Black River drainage and Little Colorado River (Nedeau et al., 2005). In Utah the only recent records are widely spaced, Big Creek and Reddin Spring Pond, may be extant in the Raft River and portions of Bear River drainage (Clark and Hovingh, 1993). Hovingh (2004) found it widely distributed in the Humboldt River drainage (Lahontan Basin) in northern Nevada, Bonneville Basin in Utah, Nevada, and Wyoming, and Malheur and Warner Basins in Oregon. Also Nevada: Great Salt Lake, North Fork Humboldt, Truckee, and Carson Desert basins (NV NHP, pers. comm., 2007). Mock et al. (2004) found Bonneville Basin (Utah) population cluster with A. oregonensis from adjacent Lahontan Basin (surveyed in Elko, Nevada) and the Middle Snake/Powder basin (Baker Co., Oregon). Mock et al. (2004) differentiated Glenn and Solano Co., California, as A. wahlamatensis thereby limiting A. californiensis populations to Utah (see above) and Arizona (Black River in Apache). In Oregon, several populations recently found in the Middle Fork John Day River and lower mainstem Umatilla River, but ID not possible (Brim Box et al., 2003; 2006), evidence indicates John Day River population includes A. californiensis/nuttalliana clade and Umatilla River population include A. oregonensis/kennerlyi and A. californiensis/nuttalliana clades in sympatry (K. Mock, UT State U., pers. comm., 2007). Chong et al. (2008) utilized specimens from the East Fork Black River, Arizona, in their phylogenetic study. Recent Washington records are mainly from the Columbia and Okanogan Rivers and some ponds adjacent to the Columbia River (Nedeau et al., 2005). In Arizona, Bequaert and Miller (1973) list the Lower Colorado, San Pedro-Wilcox, Chevelon, and Little Colorado drainages (historical) and only recent in the Black River drainage. Historically in Arizona, it was in most drainages including the Black, Salt, Santa Cruz, Verde, Gila and Colorado Rivers, but today only the upper Black River in the the Apache-Sitgreaves National Forest to at least the White Mountain Apache Reservation (AZ NHP, pers. comm., 2007). It may be extant on Chevelon Creek according to Landye (1988). Lysne and Clark (2009) found it in the Bruneau River, Idaho.
100,000 to >1,000,000 individuals
Comments: In a survey streams in California, approximately 8000 individuals were found in the upper reaches of the Eel River (none in Ten Mile, Elder, or Fox Creeks), restricted to the lower 2 km of the upper portion of the river (Cuffey, 2002).
Life History and Behavior
d'Eliscu (1972) reported the mosquitofish, Gambusia affinis, as a glochidial host in laboratory testing.
Molecular Biology and Genetics
Barcode data: Anodonta californiensis
Below is a sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species.
See the BOLD taxonomy browser for more complete information about this specimen and other sequences.
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Download FASTA File
Statistics of barcoding coverage: Anodonta californiensis
Public Records: 5
Specimens with Barcodes: 5
Species With Barcodes: 1
IUCN Red List Assessment
Red List Category
Red List Criteria
- 1996Not Evaluated
- 1994Indeterminate(Groombridge 1994)
National NatureServe Conservation Status
Rounded National Status Rank: N3 - Vulnerable
Rounded National Status Rank: N3 - Vulnerable
NatureServe Conservation Status
Rounded Global Status Rank: G3 - Vulnerable
Reasons: This species was once thought to have been widespread in the Pacific Drainage from British Columbia into Mexico, but there is considerable taxonomic confusion as to the placement of the western North American Anodonta species. The current range however is patchy, and it has apparently disappeared from the Central Valley in California. Extant occurrences in the Columbia and Snake river systems are threatened by river impoundment. If this species turns out to be a composite, its conservation status would require re-evaluation.
Intrinsic Vulnerability: Highly vulnerable
Comments: Mock et al. (2004) found populations of Anodonta (tentatively Anodonta californiensis but further taxonomic study could reveal them to be Anodonta oregonensis or Anodonta wahlamatensis) from the Bonneville Basin of Utah were strongly structured with little or no recent gene flow among extant populations that are currently hydrologically separated.
Environmental Specificity: Moderate. Generalist or community with some key requirements scarce.
Comments: It can tolerate some water pollution, but not heavy nutrient enhancement (Frest and Johannes, 1995).
In a survey of streams in California, approximately 8,000 individuals were found in the upper reaches of the Eel River (none in Ten Mile, Elder, or Fox Creeks), restricted to the lower 2 km of the upper portion of the river (Cuffey 2002).
Frest and Johannes (1995) report that the species is declining in terms of area occupied and the number of sites and individuals, and local declines have been observed throughout the range (Mock et al. 2010). It is generally widely distributed, though scarce; it is likely extirpated from the Colorado River basin in Arizona and Death Valley Basin, Los Angeles Basin, and Central Valley in Caifornia (Hovingh 2004). A recent survey of 115 sites in the Plumas, Tahoe, and Eldorado National Forests plus Lake Tahoe Basin management unit found no Anodonta specimens (in 70+ streams) except a few whole shells at 15 m depth in Donner Lake despite historical occurrences there (Howard 2008). The species is declining (possibly extirpated) in Utah with historic populations only in the Raft River (Box Elder Co.), Utah Lake (Utah Co.), and Bear Lake (Rich Co.) (Oliver and Bosworth, 1999). It is nearly extirpated from Arizona and has disappeared from the Sacramento River system. In Canada, this species occurs in British Columbia where it is declining (Metcalfe-Smith and Cudmore-Vokey 2004). Regardless of the taxonomic outcome of analysis of Anodonta molecular phylogeny, it is widely recognized that Anodonta in the western U.S. are in decline (Mock et al. 2004).
Global Short Term Trend: Decline of 10-50%
Comments: Frest and Johannes (1995) report it is declining in terms of area occupied and number of sites and individuals. Widely distributed though scarce; likely extirpated from the Colorado River basin in Arizona and Death Valley Basin, Los Angeles Basin, and Central Valley in Caifornia (Hovingh, 2004). It appears all mussels are extirpated from southern California, south of Santa Cruz (Howard, 2010). A recent survey of 115 sites in the Plumas, Tahoe, and Eldorado National Forests plus Lake Tahoe Basin management unit found no Anodonta specimens (0 of 70+ streams) except a few whole shells at 15 m depth in Donner Lake despite historical occurrences there (Howard, 2008). The species is declining (possibly extirpated) in Utah with historic populations only in the Raft River (Box Elder Co.), Utah Lake (Utah Co.), and Bear Lake (Rich Co.) (Oliver and Bosworth, 1999). It is nearly extirpated from Arizona and has disappeared from the Sacramento River system. In Canada, this species occurs in British Columbia where it is declining (Metcalfe-Smith and Cudmore-Vokey, 2004). Regardless of the taxonomic outcome of analysis of Anodonta molecular phylogeny, it is widely recognized that Anodonta in the western U.S. are in decline (Mock et al., 2004).
Global Long Term Trend: Decline of 30-50%
Comments: Range has been drastically reduced and the species has become extirpated from much of Utah, the Sacramento River system, and most of Arizona.
Mock et al. (2004) found that populations of Anodonta (tentatively Anodonta californiensis but further taxonomic study could reveal them to be Anodonta oregonensis or Anodonta wahlamatensis) from the Bonneville Basin of Utah were strongly structured with little or no recent gene flow among extant populations which are currently hydrologically separated. This fragmentation makes the populations vulnerable to threats.
Degree of Threat: Unknown
Comments: Threats include pollution; diversion of rivers for irrigation, hydroelectric, and water supply projects; elimination of natural fish hosts; eutropification due to agricultural runoff and urbanization; impoundments.
Biological Research Needs: Nonnative species are frequently the target of eradication efforts in the western U.S., but they may be serving as host fish for species in the western Anodonta complex in the absence of native host fish and fish stockign may result in unwanted gene flow between geographically disjunct populations. Broad scale analyses of genetic and mophological variation among Anodonta in western North America is necessary.
Global Protection: Unknown whether any occurrences are appropriately protected and managed
Names and Taxonomy
Comments: Since the time of Call (1884) there has been much confusion regarding the taxonomic status of this and other floaters (Anodonta) of western North America. Isaac Lea (1838) described Anodonta wahlametensis, Anodonta nuttalliana, and Anodonta oregonensis from the same site ("Wahlamet [Willamette River], near its junction with the Columbia River [Oregon]") all in the same publication. Under the Rule of First Revisor (ICZN), Call (1884) considered Anodonta nuttalliana to include, as synonyms, Anodonta wahlametensis, Anodonta oregonensis, and Anodonta californiensis. Call (1884) considered Anodonta nuttalliana to include, as synonyms, Anodonta wahlametensis, Anodonta oregonensis, and Anodonta californiensis. Recent authors (e.g., Burch, 1975, Clarke, 1981; Turgeon et al., 1998), however, have considered A. californiensis, A. nuttalliana, and A. oregonensis to be distinct. Some authors even continue to recognize Anodonta wahlamatensis as a distinct species (Frest and Johannes, 1995; Taylor, 1981; Henderson, 1929) while most place it in the synonymy of A. nuttaliana (Burch, 1975; Turgeon et al., 1998). Whether A. wahlamatensis should be removed from the synonymy of A. nuttalliana will depend on future anatomical and genetic work on western Anodonta. According to T. Frest, Anodonta nuttalliana has been revised to the following; Anodonta nuttalliana nuttalliana and Anodonta nuttalliana wahlametensis = Anodonta wahlametensis, and, Anodonta nuttalliana idahoensis and Anodonta nuttalliana californiensis = Anodonta californiensis (pers. comm. Amy Stock, WA-NHP, 1996). Considerable taxonomic confusion surrounds this species complex. Mock et al. (2004; 2005) found a lack of resolution (very little nuclear diversity) in phylogenetic reconstructions of Anodonta (A. californiensis, A. oregonensis, A. wahlamatensis) populations in the Bonneville Basin, Utah, but there was a tendency for the Bonneville Basin Anodonta (tentatively A. californiensis) to cluster with A. oregonensis from the adjacent Lahontan Basin in Nevada. Recently, Zanatta et al. (2007) supported the monophyly of both Pyganodon and Utterbackia using mutation coding of allozyme data, but also resolved the Eurasian Anodonta cygnea to Pyganodon, Utterbackia, and North American Anodonta; indicating futher phylogenetic analysis of the Anodontinae is required including both North American and Eurasian species. In a phylogenetic analysis of western North American Anodonta using topotypic material as was available, Chong et al. (2008) found three deeply divided lineages: one clade including Anodonta oregonensis and Anodonta kennerlyi, one clade including Anodonta californiensis and Anodonta nuttalliana, and one clade including Anodonta beringiana.
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