U.S. Fish & Wildlife Service Slabside Pearlymussel Pleuronaia (=Lexingtonia) dolabelloides

foot of P. barnesiana and F. subrotunda may be pale orange, but is usually always tan or white. The nacre is usually white, but may be tinged with yellow, having some iridescence posteriorly.

Biology and Life History The slabside pearlymussel, as with other adult freshwater , are filter feeders, siphoning phytoplankton, diatoms, and other microorganisms from the water column. Though for the first several months (as juveniles), mussels will utilize foot (pedal) feeding, feeding on algae and detritus. Though no age specific information is available for the slabside pearlymussel, it is thought to be relatively long-lived, possibly living several decades, considering that it is a moderately- sized heavy-shelled riverine species.

The slabside pearlymussel is a short term, summer brooder, with females brooding glochidia (larval life stage) from mid May through early August. The larval life stage, glochidia, of Adult Pleuronaia dolabelloides (69 mm) collected freshdead September 15, 2005, freshwater mussels is an obligate from the Duck River at Slick Shoals, Maury County, TN. parasite on fish, where glochidia must come in contact with a specific host Lead Region – USFWS Southeast (IV) variability in shell shape), with fish(es) in order for their survival to be Region very solid, heavy valves that are ensured. Glochidia have been reported moderately inflated. The periostracum for the slabside pearlymussel in Lead Field Office – North Carolina is tawny to brown, often greenish stream drift from mid June to mid-late Ecological Services Field Office, yellow in juveniles, usually with a August in the North Holston River, VA. Ashville, NC few interrupted green rays of vaiable Natural infestations of glochidia from width. The rays often do not extend to the slabside pearlymussel have been Robert S. Butler (Field Contact) the ventral margin. reported on several Notropis species 828/258 3939, ext. 235 in the shiner family (Cyprinidae), It closely resembles Pleuronaia including Notropis arommus (Popeye Shiner), Notropis leuciodus ( Current Status – Candidate (Listing barnesiana and oviforme, Shiner), Notropis photogenis (Silver Priority 5), Non-petitioned it also resembles Fusconaia cor, F. cuneolus, and some young F. Shiner), Notropis rubellus (Rosyface Shiner), Notropis rubricroceus Description subrotunda. The slabside pearlymussel can be separated from all of these by (Saffron Shiner), and Notropis The slabside pearlymussel is a telescopes (Telescope Shiner), as well moderately sized , with mature its ventrally curved posterior ridge and generally steeper posterior slope. as smallmouth bass (Micropterus individuals reaching lengths of 85 mm. dolomieu). The shell is moderately compressed The foot of the slabside pearlymussel and generally subtriangular in is almost always bright orange, while shape (but may exhibit considerable the foot of F. cor, F. cuneolus, and P. oviforme are always tan or white, the U.S. Fish & Wildlife Service

Population Status and Distribution The slabside pearlymussel’s distribution is restricted to the Cumberland ( and Tennessee) and Tennessee (, Tennessee, ) River systems. Currently, distribution is limited to nine streams in the Tennessee River system, and is believed extirpated from the Cumberland River system. It is currently extant in the Clinch, Powell, Elk, Duck, and Hiwassee rivers in Tennessee, the North Fork and Middle Fork Holston rivers in Virginia, and the Paint Rock River and a short reach of Bear Creek in Alabama. Habitat The slabside pearlymussel is primarily a large creek to moderately-sized river species. It generally is found in gravel substrates with interstitial sand, with moderate current, at depths less than 1 meter deep in moderate to swift current velocities. This species requires flowing, well oxygenated Pleuronaia dolabelloides (43 mm) collected freshdead from muskrat midden waters to thrive. July18, 2007, in the Paint Rock River, near the The Nature Conservancy Roy B. Whitaker Preserve, Jackson County, AL. Threats Potential partners, key contacts, and The primary reason for the decline Recovery Goals Recovery of this species is possible, potential funding sources of the slabside pearlymussel, and but would require a multi-state, other mussel species in the eastern multi-agency approach. Current United States, is habitat loss and Potential Partners: ADCNR, TWRA, extant populations of slabside degradation, with population losses VGIF, GSA, TVA, TNC, WWF, ACOE pearlymussel should be protected due to impoundments probably from further degradation by restoring contributing more than any other Key Contacts: FWS (Paul Hartfield- and protecting riparian habitat, and single factor. The majority of the JAMS, Andy Ford, Jeff Powell-AFO, implementing further measures to Tennessee and Cumberland River Dwight Cooley-Wheeler NWR), improve water quality. These water and main stems and many of their largest ADCNR (Paul Johnson, Jeff Garner), stream habitat quality improvements tributaries are now impounded. By GSA (Stuart McGregor), TNC (Paul can make it possible for extant mussel the mid- to late-1970’s, around 20 Freeman), WWF (Judy Takats), TVA populations to expand in some new percent of the Tennessee River and (Peggy Shute). river reaches, and may lead to agency its tributaries with drainages larger personnel augmenting depleted stocks than 25 square miles were impounded Potential Funding Sources: Federal or reintroducing extirpated mussel by the Tennessee Valley Authority (Region 4 flex funding, Preventing populations in other streams. TVA and (TVA). Approximately 90 percent of Extinction/Showing Success); States other agencies responsible for dam the Cumberland River downstream (State Wildlife Grants); TNC and operation, have and can modify water of Cumberland Falls is either WWF (individual contributions/ releases from its dams to improve impounded or adversely impacted initiatives); TVA (TBD), others (TBD). water quality, or better reflect a more by cold water releases. Resulting nature flow regime below the dams. downstream impacts resulting from March 2012 dam construction includes; thermal alterations, changes in channel Private landowners could also play an characteristics, altered flow regime, important role in the recovery of the daily discharge fluctuations, increased slabside pearlymussel. Cooperative silt loads, and altered fish communities, landowners could though numerous to name a few. Other impacts to habitat government and non-government grant include; instream gravel mining, coal and cost-share programs, protect, mining, contaminant (point and non- restore, and preserve riparian habitat. point source) discharges, and siltation Restoring and protecting habiatats and general sedimentation. essential for this species’ continued survival and recovery.