Lampsilis rafinesqueana 

Scope: Global
Language: English

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Taxonomy [top]

Kingdom Phylum Class Order Family
Animalia Mollusca Bivalvia Unionoida Unionidae

Scientific Name: Lampsilis rafinesqueana Frierson, 1927
Common Name(s):
English Neosho Mucket, Neosho Pearlymussel, Neosho Pearly Mussel
Actinonaias rafinesqueana (Frierson, 1927)
Taxonomic Notes: A list of synonyms for this species can be found on The MUSSEL project web site (Graf and Cummings 2011).

Assessment Information [top]

Red List Category & Criteria: Endangered A2ac ver 3.1
Year Published: 2012
Date Assessed: 2012-06-07
Assessor(s): Cummings, K. & Cordeiro, J.
Reviewer(s): Bohm, M., Seddon, M. & Collen, B.
Contributor(s): Richman, N., Dyer, E., Soulsby, A.-M., Whitton, F., Kasthala, G., McGuinness, S., De Silva, R., Milligan, HT, Herdson, R., Thorley, J., McMillan, K., Collins, A., Offord, S. & Duncan, C.
Lampsilis rafinesqueana has been assessed as Endangered under criterion A2ac, as this species has experienced a 70% reduction in its range (USFWS 2003) over the past 25-50 years, which adequately represents three generation lengths of this species. Threats continue, and include habitat destruction and modification due to impoundments, siltation, and pollution. Conservation measures including species and site protection are necessary to ensure the long-term survival of this species, and additional research is needed into the population status, threats and effectiveness of conservation measures.
Previously published Red List assessments:

Geographic Range [top]

Range Description:This species is endemic to the Neosho and Verdigris basins of the Arkansas River system in Kansas, Missouri, Oklahoma and Arkansas. Distribution of relic shell material indicates that the species was once widespread throughout these basins. It was historically reported from the Illinois River in Oklahoma and Arkansas; the Neosho River in Oklahoma and Kansas; Neosho River tributaries, including the Elk River in Missouri, Cottonwood River in Kansas, and the Spring River in Oklahoma, Kansas, and Missouri, and Spring River tributaries, North Fork Spring River and Indian Creek in Missouri, and Shoal and Center Creeks in Kansas and Missouri; the Verdigris River in Oklahoma and Kansas, and its tributaries, Caney River in Oklahoma and Kansas, and Fall River in Kansas (USFWS 2003). Recent status surveys conducted throughout this area indicate that the species has been extirpated from much of its range. In the Neosho River basin, the species now survives in the Neosho River (KS), Elk River (MO), Spring River (MO, KS, possibly OK), North Fork Spring River (MO), Illinois River (OK, AR), and Shoal, Indian and Center creeks (MO). In the Verdigris basin, the species survives in the Verdigris River (KS) and Fall River (KS) (USFWS 2003). Its extent of occurrence is estimated as approximately 70,000 km2.
Countries occurrence:
United States (Arkansas, Kansas, Missouri, Oklahoma)
Additional data:
Range Map:Click here to open the map viewer and explore range.

Population [top]

Population:Currently, approximately 70 occurrences are known, of which ca. 30% are of good to best viability, and the remainder are mostly low to no viability. Historically, many hundreds of occurrences were estimated. In Arkansas, the Neosho Mucket was found at 19 of 22 survey sites in the Illinois River, Washington/Benton Counties (USFWS 2003) and it was once considered locally abundant in second order streams of the system downstream to the Oklahoma line (Harris and Gordon 1987). The species has not been found in surveys of other tributaries of the Arkansas River in Arkansas. In Oklahoma, living Neosho Muckets were found to be locally common in about 92 km (55 mi) of the Illinois River from the Oklahoma/Arkansas state line (Harris et al. 1997), downstream to the headwaters of Tenkiller Lake, Cherokee County, Oklahoma (Mather 1990). Branson (1984) cited Oklahoma distribution as the Big Caney River; Verdigris River and Illinois River; Illinois River at Moodys (Cherokee Co.). More recent surveys in northeastern Oklahoma (Vaughn 1995, 1996, 1997, 1998) found Neosho Muckets locally common at 9 of 42 sites on the Illinois River. Relic Neosho Mucket shells confirmed the historic presence of the species at the Spring, Neosho, Verdigris, and Caney Rivers with fresh dead shells at 2 sites on the Spring River. The results of these recent surveys suggest the Neosho Mucket has been extirpated from the Caney, Verdigris, Neosho, and Spring Rivers in Oklahoma (Mather 1990, Vaughn 1995, 1996, 1997, 1998). Kansas distribution includes a small area in the southeastern part of the state in the Verdigris, Fall, Neosho, and Spring River but relic shells indicate it once lived farther west in Kansas (Couch 1997). Obermeyer et al. (1997) cites extant populations in the Neosho, Fall, and Verdigris Rivers with historical occurences in the Cottonwood, South Fork Cottonwood, Shoal Creek, Otter Creek, and Caney Rivers. Living specimens or fresh dead shells were found in the lower Fall River, Greenwood and Wilson Counties, Kansas; the Verdigris River between the Toronto Lake Dam and the confluence of the Elk River, Wilson and Montgomery Counties, Kansas (Miller and Lynott 2006, Combes and Edds 2005); the Neosho River between the John Redmond Reservoir Dam and the Parsons City Dam in Coffey, Allen, and Neosho Counties, Kansas; and the Spring and North Fork Spring Rivers, and Center and Shoal Creeks in Cherokee County, Kansas, and Jasper County, Missouri (Obermeyer et al. 1997a, Obermeyer 1999). In Center Creek, Jasper County, Missouri, only a single fresh dead shell was found. Oesch (1995) cited Missouri distribution as the Spring River, Center Creek, Shoal Creek, and the Elk River (see USFWS 2003). Recently only dead shells were found in surveys of the Marais des Cygnes, Elk, and Fall Rivers in Kansas (Combes and Edds 2005).

In Oklahoma, living Neosho Muckets were found to be locally common in about 92 km (55 mi) of the Illinois River from the Oklahoma/Arkansas state line, downstream to the headwaters of Tenkiller Lake, Cherokee County, Oklahoma (Mather 1990). The population within the survey reach was estimated at more than 1,200 individuals. Vaughn (1997) estimated the population within the Oklahoma portion of the Illinois River (the same reach surveyed by Mather in 1990) at between 500 and 1,000 Neosho Muckets. Although some evidence of reproduction was observed, there was little evidence of recruitment into the population. Neosho Muckets were relatively rare in the Fall, Verdigris, Neosho, and North Fork Spring Rivers, and Shoal Creek, representing from 0.2-1.7 percent of all live mussels collected, and were not found at all stations surveyed. Neosho Muckets were most abundant in a short reach (~10 km (6 mi)) of the Spring River, between the Missouri/Kansas state Line and the confluence of Center Creek, where it was the most abundant species found at 11 collection sites (see USFWS 2003).

This species is undergoing range contraction and continuing to decline through most of its range. Low recruitment is evident through most of its range. Decline appears slow, approx 25-50 years due to long lifespan (20+ years). The Neosho Mucket has been extirpated from approximately 70% of its historic range. Most of this extirpation has occurred within the Oklahoma and Kansas portions of its range (USFWS 2003). Based upon Obermeyer et al. (1997a) and others (Cope 1979, Cope and Distler 1985, Metcalf 1980), the Neosho Mucket has been extirpated from the Elk, Caney, Cottonwood, and South Fork of the Cottonwood Rivers, the Neosho River above John Redmond Reservoir, the Verdigris River above Toronto Lake, the Fall River above Fall River Lake, and the lower reaches of the Spring River, Shoal and Center Creeks in Kansas, and Indian Creek in Missouri (see USFWS 2003).
Current Population Trend:Decreasing
Additional data:
Number of mature individuals:100000
Population severely fragmented:No

Habitat and Ecology [top]

Habitat and Ecology:The species is found in a variety of habitats in large streams and small rivers. Most often, it occurs in shallow riffles and runs with a predominantly gravel substrate. A survey on the Illinois River found this species concentrated in silty backwater areas (Mather 1990).
Direct life-history data are not available for this species. Freshwater mussels are highly variable in their longevity from species to species (e.g. Haag and Rypel 2011). Studies have shown longevity of Lampsilis species to range from 13 to 25 years (from populations of L. ornata, L. straminea and L. teres; Haag and Rypel 2011). Lampsilis ornata was found to mature at two years of age (Haag and Staton 2003). Assuming a similar longevity for Lampsilis abrupta, and conservatively assuming age of maturity to be somewhere between 2 and 9 years (average of 5-6 years; Haag and Staton 2003), we estimate a generation length (estimated as the average age of a parent in the population) of around eight to 17 years, with three generations spanning around 24 to 51 years. Since it has been suggested that growth ring counts may underestimate age by a factor of between three and ten (Anthony et al. 2001), we believe that the upper estimate (though still likely to be an underestimate) provides us with an adequate estimate of generation length for this species.
Congregatory:Congregatory (and dispersive)

Use and Trade [top]

Use and Trade: It was once harvested commercially; however, commercial harvest is now illegal, although private harvest of up to 5 specimens per person per day is allowed.

Threats [top]

Major Threat(s): The present or threatened destruction, modification, or curtailment of its habitat or range is the most serious threat to continued survival of this species. The reduction of habitat and range of the Neosho Mucket has been attributed to impoundment, sedimentation, agricultural pollutants (Mather 1990, Obermeyer et al. 1997b), and mining (Obermeyer et al. 1997b). At least eleven major dams have been constructed that have impounded significant portions of the historic range of the Neosho Mucket, effectively resulting in fragmented populations and habitats. The species does not tolerate lentic conditions and has not been collected from those portions of its historic habitat that have been impounded. Other contributions to habitat loss include pollution, sedimentation, eutrophication, pesticide residues, and sand and gravel mining. Other threats include overutilization for commercial, recreational, scientific, or educational purposes (note commercial harvest now illegal but private harvest of up to five specimens per person per day is allowed), disease and predation (Raccoon, Black Carp), inadequacy of existing regulatory mechanisms (construction, grazing, agriculture, silviculture, public construction works) (see USFWS 2003).

The Neosho Mucket is now limited to four drainage populations: the Neosho, Verdigris, Illinois, and Spring River drainages. Each is isolated from the others by one or more major impoundments and by extended reaches of degraded river habitat. Isolation renders the four extant drainage populations vulnerable to random catastrophic events (e.g., flood scour, drought, toxic spills, etc.). Recent collections indicate Neosho Mucket recruitment is limited. All extant populations are currently dominated by older aged cohorts, and juvenile Muckets are rare (USFWS 2003).

Conservation Actions [top]

Conservation Actions: This species was listed as a federal candidate in the U.S. in 2004.

No fully protected sites are known. The species is protected from commercial harvest in some streams. The Neosho Mucket is protected under Kansas and Oklahoma state laws as an endangered species. The Illinois River in Oklahoma is a state-designated mussel sanctuary, and no mussel harvest is allowed. The species is not protected in Arkansas and Missouri, beyond general mussel harvest laws. There is currently no requirement within the scope of federal environmental laws to specifically consider the Neosho mucket during federal activities or ensure that federal projects will not jeopardise its continued existence (USFWS 2003). A pilot propagation project was carried out in the Fall River, Kansas in the Fall River Wildlife Refuge where 19,550 laboratory reared juveniles were released (Barnhart and Baird 2000). This propagation is showing some signs of success in Kansas streams (Anderson 2006). In southeastern Kansas, this species is protected from commercial harvest in the Verdigris River Freshwater Mussel Refuge (Miller 1993).

Williams et al. (2010) lists this species as threatened according to the American Fisheries Society (AFS) assessment. Further research is required regarding the taxonomy, population status, ecology and threats impacting this species. Conservation measures including species and site protection are also necessary to ensure the long-term survival of this species.

Further research is needed on the population status, ecology, threats and the effectiveness of conservation actions, in order to improve the conservation status of this species. Continued monitoring is also recommended, so that effectiveness of conservation measures can be assessed.

Citation: Cummings, K. & Cordeiro, J. 2012. Lampsilis rafinesqueana. The IUCN Red List of Threatened Species 2012: e.T11242A501662. . Downloaded on 23 April 2018.
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