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Freshwater Mussels (Bivalvia: Margaritiferidae and Unionidae) of the Buffalo River Drainage, Tennessee
Matthew P. Reed, Gerald R. Dinkins, and Steven A. Ahlstedt

Southeastern Naturalist, Volume 18, Issue 2 (2019): 346–372

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Southeastern Naturalist M.P. Reed, G.R. Dinkins, and S.A. Ahlstedt 2019 Vol. 18, No. 2 346 2019 SOUTHEASTERN NATURALIST 18(2):346–372 Freshwater Mussels (Bivalvia: Margaritiferidae and Unionidae) of the Buffalo River Drainage, Tennessee Matthew P. Reed1,*, Gerald R. Dinkins2, and Steven A. Ahlstedt3 Abstract - The Buffalo River in Tennessee historically contained a rich diversity of freshwater mussels. Sampling efforts in the 1980s documented declines in most of the main channel. Recent collection data indicated recovery in the upper and lower reaches of the river. The objective of this study was to update the current status, distribution, and species composition of the mussel fauna in the main channel and major tributaries through qualitative sampling, and document community structure using quantitative sampling at the most diverse location in the main channel for use in future monitoring efforts. In the qualitative sampling portion of this study, timed searches established catch-per-unit effort (CPUE) at intervals of ~5 river miles in the main channel and tributaries. We recorded a total of 36 species at 62 sites, including 3 federally protected species: Margaritifera monodonta (Spectaclecase), Pleuronaia dolabelloides (Slabside Pearlymussel), and Theliderma cylindrica (Rabbitsfoot). An additional 3 species being considered for the federal endangered species list were also found extant in the main channel: Obovaria subrotunda (Round Hickorynut), Pleuronaia barnesiana (Tennessee Pigtoe), and Toxolasma lividum (Purple Lilliput). Multiple sites in the upper and lower mainstem were suitable for reintroduction of species. These findings should be considered in future management and conservation efforts. Introduction and Historical Review Tennessee is one of the most biologically rich inland states and has the highest number of freshwater fish species (Boschung and Mayden 2004, Etnier and Starnes 1993) and the second highest number of freshwater mussels among US states (Parmalee and Bogan 1998, Williams et al. 2008). Parmalee and Bogan (1998) reported 129 mussel taxa historically known to occur in Tennessee, and subsequent taxonomic changes and recent surveys have raised this number to 139 (G.R. Dinkins, unpubl. data). To date, Tennessee has lost roughly 26 taxa to extinction or statewide extirpation, lowering the total number of extant mussel species to 113, of which 3 have uncertain status (G.R. Dinkins, unpubl. data). The Buffalo River joins the Duck River ~15.5 river miles upstream of the confluence with the Tennessee River, and is the largest tributary to the Duck River. The Duck River has long been recognized as exceptionally diverse, and is home to roughly 151 species of fish, 66 species of mussels, and 22 species of aquatic snails (Ahlstedt et al. 2017, Etnier and Starnes 1993, Hubbs et al. 2011). In contrast, the Buffalo River has received little attention except for occasional surveys at a few isolated locations on the main channel. 1Tennessee Department of Transportation, 7512 Volkswagen Drive, Chattanoooga, TN 37416. 2McClung Museum of Natural History and Culture, University of Tennessee, 1327 Circle Park Drive, Knoxville, TN 37996. 3PO Box 460, Norris, TN 37828. *Corresponding author - matthew.reed@tn.gov. Manuscript Editor: Paul M. Stewart Southeastern Naturalist 347 M.P. Reed, G.R. Dinkins, and S.A. Ahlstedt 2019 Vol. 18, No. 2 Only a few published surveys have documented the historical mussel fauna of the Buffalo River. Arnold Ortmann visited the Buffalo River in 1922 during a mussel study of the Duck River drainage (Ortmann 1924) and sampled near Riverside (Buffalo River Mile [BRM] 80.5). He noted a substantial mussel fauna, and reported 20 species. In 1931, Calvin Goodrich and Henry van der Schalie sampled BRM 80.5, BRM 41.0, BRM 31.6, and BRM 19.1. Their results, published over 40 y after the survey, added 13 species to Ortmann’s list (van der Schalie 1973). Goodrich and van der Schalie’s most speciose site was BRM 19.1 (near Lobelville), where they reported 29 species. Van der Schalie (1973:49) noted that “the Duck and Buffalo rivers had a surprisingly rich mussel fauna, both in the numbers of species and in individuals”. Based on the number of mussels found at BRM 41.0, BRM 31.6, and BRM 19.1, Van der Schalie (1973:49) concluded the Duck and Buffalo Rivers “have some of the finest shoals in the world but, as previously indicated, the mussels have now been depleted drastically”. The decline of the mussel fauna in the Buffalo River was also noted by Isom and Yokley (1968). In their field notes accompanying speciments deposited in the Museum of Biological Diversity at Ohio State Universtiy (OSUM), they wrote, “The Buffalo is a clear, cool, rapidly flowing small river with no evident pollution. In spite of limestone bedrock, cobbles, and gravel, the mollusks were not abundant.” Isom and Yokley found no live mussels or dead shells when they visited BRM 80.5, but they found 16 species at BRM 74.8 and added several new species to the historical record. David Stansbery visited the Buffalo River in 1972 and made this entry in his fieldnotes accompanying speciments deposited in OSUM: “Water low, clear and cool … Naiades [freshwater mussels] all but absent, a single Toxolasma lividus lividus [= Toxolasma lividum Rafinesque, 1831] was taken alive along with a few dead shells of other species.” In 1980, biologists from the Tennessee Valley Authority (TVA) sampled 24 sites on the Buffalo River as part of the Cumberlandian Mollusk Conservation Program and Columbia Dam project on the Duck River (Ahlstedt 1991). They found only 3 or fewer live species at any site, and most sites yielded none. Initially, more sites were to be surveyed, but the study was terminated because of the paucity of mussels encountered. These surveys did not investigate the reason(s) for the decline of the mussel fauna in the Buffalo River, but Fitz (1973) and Mast and Turk (1999) suggested the decline was associated with degraded water quality caused by anthropogenic activities. In 2002, a survey of the Duck River drainage included 5 sites in the Buffalo River previously surveyed by earlier investigators (Ahlstedt et al. 2017). Of the 9 species found across the 5 sites, none represented a new species for the river. Those authors observed severe substrate destabilization and silt accumulation, and mussels were extremely rare. Despite the lack of a drainage-wide survey, based on these reports, the Buffalo River was known to have contained 43 species, including 7 that are now federally endangered: Epioblasma ahlstedti (Duck River Dartersnapper), E. aureola (Golden Riffleshell), Hemistena lata (Cracking Pearlymussel), Pleuronaia dolabelloides (Slabside Pearlymussel), Ptychobranchus subtentus (Fluted Kidneyshell), Southeastern Naturalist M.P. Reed, G.R. Dinkins, and S.A. Ahlstedt 2019 Vol. 18, No. 2 348 Theliderma cylindrica (Rabbitsfoot), and Toxolasma cylindrellus (Pale Lilliput) (Appendix 1). In 2012, we recognized the need for a thorough survey of the Buffalo River when biologists from the TVA brought several fresh dead mussels collected during a fish survey in the lower reach to the McClung Museum of Natural History and Culture at the University of Tennessee. In this sample of shells, we identified 2 species not previously reported from the Buffalo River: Margaritifera monodonta (Spectaclecase [endangered]) and Ellipsaria lineolata (Butterfly). The sample also included Eurynia dilatata (Spike), which had not been seen in the Buffalo River since 1922 (Ortmann 1924), Cyclonaias pustulosa (Pimpleback), and Pleuronaia dolabelloides, not seen since 1931 (van der Schalie 1973). Study Area The Buffalo River is located in western Middle Tennessee in the Western Highland Rim of the Interior Low Plateau physiographic province (Mast and Turk 1999) and is one of the state’s longest free-flowing rivers (201 km) (Fig. 1). Rising in Lawrence County, the river flows west through Lewis and Wayne counties, then turns north to flow through Perry and Humphreys counties, draining ~1227 km2. The upper Buffalo River, in Lawrence County, is designated a “State Scenic River” under the Tennessee State Scenic Rivers Act. The Western Highland Rim is highly dissected by perennial streams that create irregular topography consisting of peneplain ridgelines and flat-bottomed drainages, often separated by steep-sided ridges. The Western subdivision of the Highland Rim province encompasses the entire Buffalo River, and varies in elevation from 157 m to 305 m. Mississippian limestone, chert, sandstone, and shale compose primary deposits, with sinkholes, caves, and karst topography occurring throughout the region (Smalley 1981). Mean temperatures vary from 8.8 °C in January to 31.6 °C in July. Mean annual precipitation is 142 cm, with peak precipitation occurring in May and December. May is generally the wettest month and averages 15.5 cm of precipitation. The driest months are August through October. Mast and Turk (1999) and the Tennessee Department of Environment and Conservation (TDEC 2005) described land use in the Buffalo River watershed as primarily forest (77%) and agriculture (18%). Over 90% of the watershed is private land, and urban development constitutes less than 1%. Despite its rural setting, the Buffalo River drainage experienced considerable development from the mid-1960s to mid-1980s. Methods Museum records We collected records from several museums to supplement the list of species in past survey reports: Carnegie Museum of Natural History (CM), McClung Museum of Natural History and Culture at the University of Tennessee (UTMM), North Carolina State Museum of Natural Sciences (NCMNS), Museum of Biological Diversity at The Ohio State University (OSUM), and University of Michigan Museum of Zoology (UMMZ). Southeastern Naturalist 349 M.P. Reed, G.R. Dinkins, and S.A. Ahlstedt 2019 Vol. 18, No. 2 Qualitative sampling We sampled 47 sites in the main channel Buffalo River and 15 sites in tributary streams between October 2012 and December 2015 (Table 1, Fig. 1). We selected sampling locations surveyed in previous investigations and new sites that we considered to possess suitable habitat. Each locality was recorded in decimal degrees Figure 1. Sampling localities for mussels in the Buffalo River drainage in Lawrence, Lewis, Wayne, Perry, and Humphreys counties, TN. Southeastern Naturalist M.P. Reed, G.R. Dinkins, and S.A. Ahlstedt 2019 Vol. 18, No. 2 350 Table 1. Location of mussel survey sites in the Buffalo River system, TN. [Table continued on following page.] Site/location Latitude (°N) Longitude (°W) River-mile Date 1 Buffalo River 35.9957330 87.8407500 0.2 11 October 2012 2 Buffalo River 35.9894400 87.8555600 1.9 16 November 2012 3 Buffalo River 35.9850500 87.8603100 2.2 16 November 2012 4 Buffalo River 35.9784300 87.8626100 2.8 16 November 2012 5 Buffalo River 35.9746800 87.8627500 3.2 16 November 2012 6 Buffalo River 35.9722400 87.8577100 3.5 17 November 2012 7 Buffalo River 35.9657000 87.8541400 4.0 17 November 2012 8 Buffalo River 35.9567100 87.8524000 4.6 17 November 2012 9 Buffalo River 35.9517200 87.8522000 4.9 17 November 2012 10 Buffalo River 35.9316590 87.8501960 6.8 11 October 2013 11 Buffalo River 35.9195000 87.8461000 8.0 11 October 2013 12 Buffalo River 35.8766670 87.8303500 12.0 11 October 2013 13 Buffalo River 35.8576170 87.8135670 13.8 30 August 2013 14 Buffalo River 35.8279670 87.8086830 16.3 30 August 2013 15 Buffalo River 35.8121830 87.7964500 17.7 30 August 2013 16 Buffalo River 35.8126170 87.7759000 19.4 30 August 2013 17 Buffalo River 35.7867330 87.7766670 22.4 29 August 2013 18 Buffalo River 35.7620830 87.7727500 25.8 29 August 2013 19 Buffalo River 35.7049100 87.7937700 32.0 10 August 2013 20 Buffalo River 35.6880300 87.8026200 34.3 10 Aug 2013 21 Buffalo River 35.6154300 87.8320300 41.4 9 August 2013 22 Buffalo River 35.6040700 87.8387900 42.8 9 August 2013 23 Buffalo River 35.5827400 87.8385200 45.6 9 August 2013 24 Buffalo River 35.5432900 87.8201000 52.1 9 August 2013 25 Buffalo River 35.5235500 87.8419670 55.1 18 December 2012 26 Buffalo River 35.5206330 87.8435670 55.6 18 December 2012 27 Buffalo River 35.5125267 87.8395990 56.0 18 December 2012 28 Buffalo River 35.5050500 87.8266330 57.4 18 December 2012 29 Buffalo River 35.5004000 87.8322330 58.0 18 December 2012 30 Buffalo River 35.4890835 87.8342990 59.0 18 December 2012 31 Buffalo River 35.4657500 87.8476000 62.7 21 June 2013 32 Buffalo River 35.4734830 87.8148670 67.4 21 June 2013 33 Buffalo River 35.4556670 87.8029500 70.6 21 June 2013 34 Buffalo River 35.4551000 87.7737670 73.5 25 May 2013 35 Buffalo River 35.4343500 87.7210000 78.7 25 May 2013 36 Buffalo River 35.4360170 87.6990500 80.5 25 May 2013 37 Buffalo River 35.4427170 87.6451170 87.0 24 May 2013 38 Buffalo River 35.4521500 87.6030170 90.6 24 May 2013 39 Buffalo River 35.4497700 87.5690900 93.6 17 July 2013 40 Buffalo River 35.4625800 87.5352000 98.2 17 July 2013 41 Buffalo River 35.4681200 87.5012900 100.6 17 July 2013 42 Buffalo River 35.4645100 87.4786700 102.9 16 July 2013 43 Buffalo River 35.4654800 87.4652900 105.3 17 July 2013 44 Buffalo River 35.4367000 87.4232300 111.3 17 July 2013 45 Buffalo River 35.3971400 87.3877100 116.7 18 July 2013 46 Buffalo River 35.3939800 87.3111500 121.0 18 July 2013 47 Buffalo River 35.3911100 87.2994600 122.0 18 July 2013 48 Cane Creek 35.7048170 87.7554670 3.4 11 December 2012 49 Cane Creek 35.7086670 87.7601500 2.4 11 December 2012 Southeastern Naturalist 351 M.P. Reed, G.R. Dinkins, and S.A. Ahlstedt 2019 Vol. 18, No. 2 using a hand-held global positioning system unit (Garmin GPSMAP 76Cx unit, WAAS enabled) and is reported in river miles because this is the increment used in US Geological Survey 7.5 minute topographic maps. Mussels encountered at each sampling location were removed from the substrate and held in a submerged mesh bag until they were sorted and identified. Fresh-dead (shiny nacre, hinge ligament intact) and relic shells (weathered periostracum, faded or chalky nacre) were identified, counted, recorded on a field data sheet, and taken to UTMM where they were cleaned, verified, and catalogued. Live mussels were measured (anterior to posterior in millimeters) using dial calipers, photographed, and returned to the substrate. Each site was surveyed by at least 2 experienced biologists for 1 h or more. Shorelines and adjacent submerged habitats were searched for shells deposited by Ondatra zibethicus (L.) (Muskrat) or high water. Quantitative sampling Based on the results of the qualitative survey, we chose the most diverse and abundant mussel community for quantitative sampling in November 2013 (shoal at BRM 3.2). We established parallel transects in an area measuring 67 m long and 35 m wide (2345 m2). Transects were oriented perpendicular to the shoreline, spaced at 6-m intervals, and spanned the wetted channel. A total of 100 quadrats (0.25 m2) evenly spaced 4 m apart along the transects was sampled using skin diving gear and SCUBA, and each quadrat was excavated to an attempted minimum depth of 15 cm. Water depth varied from a few centimeters along the right descending bank to 2 m in the thalweg, located near the left descending bank. Analyses We calculated species richness, relative abundance, and CPUE (determined as number of observed live and fresh dead mussels/snorkel time per observer x number of observers) for each site. Numerous studies involving freshwater mussels have documented the potential bias of selecting for larger individuals in qualitative versus quantitative sampling methods (Hornbach and Deneka 1996, Miller and Table 1, continued. Site/location Latitude (°N) Longitude (°W) River mile Date 50 Cane Creek 35.7077819 87.7575284 2.6 11 December 2012 51 Cane Creek 35.6992830 87.7475330 4.1 11 December 2012 52 Brush Creek 35.6751170 87.8015000 0.1 12 December 2012 53 Coon Creek 35.6349000 87.8045330 1.3 12 December 2012 54 Coon Creek 35.6375500 87.8088670 0.9 12 December 2012 55 Coon Creek 35.6377000 87.8101801 0.7 12 December 2012 56 Lower Opossum Creek 35.4878336 87.8325710 0.1 18 December 2012 57 Hurricane Creek 35.5721100 87.8019500 0.9 10 August 2013 58 Green River 35.4299440 87.7750700 2.3 19 December 2015 59 Green River 35.3431100 87.7592800 10.6 19 December 2015 60 Fortyeight Creek 35.4040640 87.6667760 4.4 19 December 2015 61 Little Buffalo River 35.4143080 87.5105710 4.8 19 December 2015 62 Little Buffalo River 35.3261060 87.4866630 15.3 19 December 2015 Southeastern Naturalist M.P. Reed, G.R. Dinkins, and S.A. Ahlstedt 2019 Vol. 18, No. 2 352 Payne 1993, Miller et al. 1993, Obermeyer 1998). To test for this potential bias, we conducted a 2-tailed Kolmogorov–Smirnov (K–S) nonparametric test (Smirnov 1948) to examine size-class variance in qualitative versus quantitative sampling data for the most abundant species, Pleuronaia dolabelloides. We hypothesized qualitative size-class data would vary significantly from quantitative size-class data. We conducted our analyses in XLSTAT statistical software. Taxonomy follows Williams et al. (2017). Results Museum records The search for Buffalo River specimens at 5 museums yielded a total of 32 species, including 4 new records from 16 collecting localities (Appendix 2): Epioblasma turgidula (Turgid Blossom), Megalonaias nervosa (Giant Washboard), Ligumia subrostrata (Pondmussel), and Utterbackiana suborbiculata (Flat Floater). Epioblasma turgidula (2 males and 1 female) and Megalonaias nervosa were collected by H. Athearn in 1966 at the Gilmore Bridge near Lobelville (BRM 22.6) (J. Smith, NCMNS, Raleigh, NC, pers. comm.). Athearn also collected M. nervosa at the US Route 412 bridge near Linden (BRM 41.0). In July 1994, S. Ahlstedt found Ligumia subrostrata (Pondmussel) in an overflow channel of the Buffalo River at Mill Bridge (BRM 24.0). There are only a few records of this species from Tennessee, but it is found throughout the Mississippi River basin (Parmalee and Bogan 1998). Ligumia subrostrata typically occurs in areas with little to no current (Williams et al. 2008), and it seems to be particularly adaptable to newly created ponds or channels, where it can be abundant. Its presence in an overflow channel of the Buffalo River, while well upstream of its previously known range in the Tennessee River drainage, is consistent with its habitat preference. Utterbackiana suborbiculata (Flat Floater) was found at Beardstown (BRM 32.6) in 1973. A large, single valve of this species was found in the Buffalo River and is cataloged at UTMM. Utterbackiana suborbiculata appears to be expanding its range upstream in both the Tennessee and Cumberland river drainages (Bates 1962, Parmalee and Bogan 1998) and it is now found in the Tennessee River as far upstream as Knoxville and in the Cumberland River as far upstream as Hartsville (G. Dinkins, pers. observ.). Williams et al. (2008) speculated U. suborbiculata has spread into the Tennessee River due to conditions associated with impoundment of the formerly free-flowing river. While the Buffalo River is completely unimpounded, Kentucky Lake impounds the lower Duck River upstream to its confluence with the Buffalo River. Qualitative results We found a total of 33 species in the qualitative survey; 2 additional species were found after the qualitative survey was completed and were added to the qualitative survey results (Appendix 3). We observed live or fresh dead mussels at 30 of the 47 main channel sites. By far, the most diverse sites were BRM 3.2 and BRM 3.5. We found no live mussels at the 5 most upstream sites (BRM 105.3 to Southeastern Naturalist 353 M.P. Reed, G.R. Dinkins, and S.A. Ahlstedt 2019 Vol. 18, No. 2 BRM 122.0). Mussel diversity varied in the main channel, and although mussels were sparse in the middle reaches compared to historical sampling efforts, we detected significant increases in the upper and lower Buffalo River. We documented Lampsilis fasciola (Wavyrayed Lampmussel) and Villosa taeniata (Painted Creekshell) at 18 and 21 sites, respectively; these were the most abundant and widespread species. Species richness and CPUE were correlated throughout the river. Sites in the middle portion of the river (BRM 30.0 to BRM 98.0) supported few live mussels. Species richness was similarly low in this stretch of the river. Tributaries to the Buffalo River (Sites 48 to 60, 62) were devoid of mussels except for a single relic Strophitus undulatus (Creeper) found in the Little Buffalo River at Site 61. We did not observe Strophitus undulatus in the main channel of the Buffalo River. The apparent lack of mussels in Buffalo River tributaries mirrors recent findings from sampling in tributaries of the Duck River (K. Irwin, Tennessee Tech University, Cookeville, TN, unpubl. data). For this reason, tributary sampling results are not included in Appendix 3. Length–frequency data indicated recent recruitment for V. taeniata (20–89 mm), L. fasciola (56–86 mm), Pleuronaia barnesiana (Tennessee Pigtoe) (27–59 mm), and P. dolabelloides (36–70 mm). We observed multiple size-classes of Potamilus alatus (Pink Heelsplitter) and T. cylindrica, but there were insufficient numbers to infer recent recruitment. During quantitative sampling at BRM 3.2, a large, submerged muskrat midden was located just outside of the study area. After a brief assessment, it became evident this midden contained a large number of fresh dead shells; these numbers are omitted from the study results. Quantitative results Quadrat excavations yielded 178 live individuals representing 20 species and an average of 1.8 mussels per 0.25-m2 quadrat (Table 2). We collected 1 live Actinonaias ligamentina (Mucket) in the quadrat excavations, which was the only individual of the species found in our study. Two federally protected species, P. dolabelloides and T. cylindrica, comprised nearly 30% of the live mussels in the samples; of these, P. dolabelloides was the most abundant (26.4%). There were multiple size-classes (11–65 mm) of this species, which indicated recent recruitment. Other species with multiple size-classes included Cyclonaias pustulosa, Cyclonaias tuberculata (Purple Wartyback), and Eurynia dilatata. Evidence of recent recruitment was inconclusive for Lampsilis fasciola, P. barnesiana, T. cylindrica, Tritogonia verrucosa (Pistolgrip), and Truncilla truncata (Deertoe) due to insufficient number of individuals. There was no significant difference in size-classes of P. dolabelloides in qualitative versus quantitative data (P = 0.093), suggesting qualitative sampling methods were not biased toward detecting larger individuals. Species of conservation concern Margaritifera monodonta (Spectaclecase). Margaritifera monodonta was once widespread in the Mississippi, Ohio, and Missouri River basins from Minnesota and western Pennsylvania south to the Gulf Southeastern Naturalist M.P. Reed, G.R. Dinkins, and S.A. Ahlstedt 2019 Vol. 18, No. 2 354 of Mexico (Parmalee and Bogan 1998). It was listed as federally endangered in 2012 (USFWS 2012). Prior to this study, it was not known to occur in the Buffalo River. Two live individuals were found in 1998 in the Tennessee River at RM 170, approximately 60 river-miles downstream of the mouth of the Duck River (Hubbs and Jones 2000), and in the early 2000s, a single individual was observed in the Duck River (USFWS 2012). To our knowledge, no additional individuals of this species have been found in the Duck River, and it appears to be equally rare in the Buffalo River. The periostracum of the specimen brought to us by the TVA fishsampling crew was fairly weathered but not overly so, and the nacre was lustrous. We cannot precisely estimate how much time had elapsed since its death, but we have found shells of M. monodonta from other locations in the Tennessee River drainage that appeared weathered soon after death; consequently, it is likely the specimen found by the TVA was alive within 1 y of its shell being found, and from this we infer that there is an extant but extremely small population remaining in the Buffalo River. Epioblasma ahlstedti (Duck River Dartersnapper). Epioblasma ahlstedti historically occurred in the Duck and Buffalo rivers, as well as the Tennessee River at Muscle Shoals and Shoal Creek, a large direct tributary to the Tennessee River (Jones 2004). Currently, it is restricted to ~48.3 river km in the Duck River, from the Old Columbia Dam upstream to Lillard Mill Table 2. Summary of quantitative sampling at BRM 3.2. Number = number observed among 100 quadrats. % Occurrence = percent of occurrence across all quadrat samples. Number of quadrats = number of quadrats occupied by species. Size (min–max if more than 1 observed) is presented for live individuals only. Species Number % occurrence # of quadrats Size (mm) Actinonaias ligamentina 1 0.6 1 49 Actinonaias pectorosa 1 0.6 1 14 Cyclonaias pustulosa 15 8.4 10 20–61 Cyclonaias tuberculata 46 26.0 25 18–99 Ellipsaria lineolata 3 1.7 2 22–54 Elliptio crassidens 3 1.7 3 111–141 Eurynia dilatata 20 11.2 15 15–85 Lampsilis fasciola 6 3.3 5 47–82 Lampsilis ovata 2 1.1 2 16–74 Lasmigona costata 2 1.1 2 82–149 Megalonaias nervosa 1 0.6 1 88 Obliquaria reflexa 1 0.6 1 29 Pleuronaia barnesiana 5 2.8 5 18–59 Pleuronaia dolabelloides 47 26.4 28 11–65 Potamilus alatus 2 1.1 2 109–113 Theliderma cylindrica 6 3.3 5 64–94 Toxolasma lividum 1 0.6 1 16 Tritogonia verrucosa 6 3.3 4 64–89 Truncilla truncata 9 5.0 8 18–37 Villosa taeniata 1 0.6 1 84 Total 178 Southeastern Naturalist 355 M.P. Reed, G.R. Dinkins, and S.A. Ahlstedt 2019 Vol. 18, No. 2 (Jones and Neves 2010, Parmalee and Bogan 1998). Its historical occurrence in the Buffalo River is based on 1 specimen found in the Buffalo River in 1931 (van der Schalie 1973) near the Humphreys/Perry County border (approximate BRM 19.0). We did not find this species in this survey. Epioblasma ahlstedti was listed as federally endangered in 1997 (as Epioblasma capsaeformis [Oyster Mussel]; USFWS 1997). Epioblasma aureola (Golden Riffleshell). Epioblasma aureola presumably occurred in numerous tributary streams of the middle and upper Tennessee River system downstream to the Duck and Buffalo rivers, but is now thought to occur only in Indian Creek, a tributary to the upper Clinch River in southwestern Virginia (Jones and Neves 2010). Its historical occurrence in the Buffalo River is based on 3 specimens found in the Buffalo River in 1931 (van der Schalie 1973) near the Humphreys/Perry County border (approximate BRM 19.0). We did not find this species in this survey. Epioblasma aureola was listed as federally endangered in 1977 (as Epioblasma florentina walkeri [Wilson and Clark] [Tan Riffleshell]; USFWS 1977). Epioblasma turgidula (Turgid Blossom). Epioblasma turgidula appears to have been endemic to the Tennessee and Cumberland River drainages in Alabama and Tennessee, where it occurred in numerous large tributary rivers and streams (Parmalee and Bogan 1998, Williams et al. 2008). H. Athearn collected 3 individuals of this species (presumably alive) in September 1966 in the Buffalo River at Gilmore Bridge (BRM 22.6) (J. Smith, pers. comm.). Epioblasma turgidula is presumed extinct and was last seen alive in 1972 in the upper Duck River (Stansbery 1976). Johnson (1978) included records for the species from the St. Francis River in Arkansas, but its taxonomic status outside of the Tennessee and Cumberland systems is uncertain and yet unresolved (J. Harris, Arkansas State University, Jonesboro, AR, pers. comm.). It was listed as federally endangered in 1976 (USFWS 1976). Hemistena lata (Cracking Pearlymussel). Hemistena lata is restricted to the Ohio River drainage, including the Tennessee and Cumberland rivers (Watters et al. 2009). There are 2 records from the Buffalo River: 1 individual was collected at BRM 19.1 in 1931 (van der Schalie 1973) and an unknown number were collected at BRM 74.8 in 1965 (Isom and Yokley 1968). We did not find H. lata in this survey. Hemistena lata was listed as federally endangered in 1989 (USFWS 1989). Obovaria subrotunda (Round Hickorynut). Obovaria subrotunda is known from parts of the Great Lakes Basin and is widespread in the Tennessee, Cumberland, and Ohio River drainages (Haag and Cicerello 2016, Parmalee and Bogan 1998, Watters et al. 2009, Williams et al. 2008). Obovaria subrotunda was first reported from the Buffalo River in 1922 (Ortmann 1922), and it was subsequently collected in 1931 and 1965 (Isom and Yokley 1968, van der Schalie 1973). We found 1 live individual at BRM 3.2 during a timed search but did not find it in the quantitative sampling at this same location. The Southeastern Naturalist M.P. Reed, G.R. Dinkins, and S.A. Ahlstedt 2019 Vol. 18, No. 2 356 USFWS is currently conducting a status assessment to determine if O. subrotunda warrants federal protection under the Endangered Species Act (ESA). Pleuronaia barnesiana (Tennessee Pigtoe). Pleuronaia barnesiana occurs in medium-sized creeks to large rivers in the Tennessee River drainage (Parmalee and Bogan 1998, Williams et al. 2008). Pleuronaia barnesiana was relatively widespread in the Buffalo River. We found live or dead shells at 13 locations from just upstream of the Duck River confluence to BRM 102.9. In the quantitative survey at BRM 3.2, P. barnesiana comprised ~3% of the live mussels found in the quadrats and several age classes were evident. The USFWS is currently conducting a status assessment to determine if P. barnesiana warrants federal protection under the ESA. Pleuronaia dolabelloides (Slabside Pearlymussel). Pleuronaia dolabelloides is endemic to the Tennessee and Cumberland River drainages and was listed as federally endangered in 2013 (USFWS 2013a). This species was one of the most abundant and wide-ranging species we found in the Buffalo River. Individuals collected from quadrats at BRM 3.2 exhibited a healthy size-class distribution (11–65 mm), with strong evidence of recent recruitment. Currently, healthy communities of P. dolabelloides persist in the upper and lower reaches of the Buffalo River (e.g., BRM 102.9 and BRM 3.2). Clinal variation in shell morphology for this species is consistent with observations made by Ortmann (1924) and Van der Schalie (1973); individuals collected upstream (e.g., BRM 102.9) were notably compressed compared to individuals at downstream sites (e.g., BRM 3.2). Pleurobema oviforme (Tennessee Clubshell). Pleurobema oviforme historically occurred in small to large rivers in the Tennessee and Cumberland River drainages, but it has disappeared from much of its historical range and is in danger of disappearing from Kentucky (Haag and Cicerello 2016). We observed relic shells of P. oviforme at 2 sites during this study— BRM 3.2 and BRM 3.5. The USFWS is currently conducting a status assessment to determine if P. oviforme warrants federal protection under the ESA. Ptychobranchus subtentus (Fluted Kidneyshell). Ptychobranchus subtentus is endemic to the Tennessee and Cumberland River drainages (Parmalee and Bogan 1998). It appears to be extirpated from Alabama (Garner et al. 2004), and populations have declined dramatically in Kentucky (Haag and Cicerello 2016). We did not find P. subtentus in this survey, and it has not been seen in the Buffalo River since 1922 at BRM 90.4 (Ortmann 1924). Ptychobranchus subtentus was listed as federally endangered in 2013 (USFWS 2013a). Theliderma cylindrica (Rabbitsfoot). Theliderma cylindrica is endemic to the Tennessee River drainage and was listed as threatened in 2013 (USFWS 2013b). The Buffalo River was not included as critical habitat for T. cylindrica, and a recent status update assumed it was extirpated from the river (USFWS 2015). During our qualitative search, T. cylindrica Southeastern Naturalist 357 M.P. Reed, G.R. Dinkins, and S.A. Ahlstedt 2019 Vol. 18, No. 2 was found to be mostly restricted to the lower reach of the Buffalo River. We documented live individuals at BRM 2.2, BRM 3.2, and BRM 17.7. Quantitative sampling at BRM 3.2 produced 6 T. cylindrica from 5 quadrat samples. Toxolasma cylindrellus (Pale Lilliput). Toxolasma cylindrellus is endemic to the middle and lower Tennessee River drainage in Tennessee and Alabama (Parmalee and Bogan 1998, Williams et al. 2008). It was thought to have been extirpated from the Duck River, but was rediscovered in 2015 in Lick Creek, a tributary to the Duck River in Maury County (D. Hubbs, Tennessee Wildlife Resource Agency, Camden, TN, pers. comm.). Prior to this discovery, the only known population occurred in a tributary of the Paint Rock River in Alabama and Tennessee. Toxolasma cylindrellus was last seen in the Buffalo River in 1922 at BRM 80.5 (Ortmann 1924), and we did not find the species in this survey. Toxolasma cylindrellus was listed as federally endangered in 1976 (USFWS 1976). Toxolasma lividum (Purple Lilliput). Toxolasma lividum occurs in the Ohio River drainage, including the Cumberland and Tennessee rivers, the Arkansas River drainage, and in the Lake Erie drainage (Parmalee and Bogan 1998, Watters et al. 2009). In the Buffalo River, it was rare and restricted to lower reaches where it occurred along the margins of backwater areas and shallow pools in soft substrate. We found a single individual during quantitative sampling at BRM 3.2. The taxonomic status of populations in the Cumberland River drainage are under review (D. Campbell, Gardner-Webb University, Boiling Springs, NC, pers. comm.), and the USFWS is currently conducting a status assessment to determine if T. lividum warrants federal protection under the ESA. The following species were not detected in our survey and may be extirpated from the Buffalo River. The date of last occurrence is given in brackets following the common name: Alasmidonta marginata (Say) (Elktoe) [1965], Alasmidonta viridis (Rafinesque) (Slippershell Mussel) [1922], Lasmigona complanata (Barnes) (White Heelsplitter) [1931], Ligumia subrostrata (Say) (Pondmussel) [1994], Medionidus conradicus (Lea) (Cumberland Moccasinshell) [1968], Pleurobema sintoxia (Rafinesque) (Round Pigtoe) [1931], Ptychobranchus fasciolaris (Rafinesque) (Kidneyshell) [1965], Utterbackia imbecillis (Say) (Paper Pondshell) [1931], and Utterbackia suborbiculata [1973]. Discussion and Recommendations The Buffalo River is a rare example of a large unimpounded stream. Our review of published literature, unpublished reports, and museum records along with our survey results indicate that the river once contained 51 freshwater mussel species (Appendix 4). Most of the river’s mussel fauna was nearly extirpated in the years following the early surveys by Ortmann, which was documented in subsequent surveys by Goodrich and van der Schalie, Isom and Yokley, and Ahlstedt. As a result, management decisions and conservation efforts aimed at recovering Southeastern Naturalist M.P. Reed, G.R. Dinkins, and S.A. Ahlstedt 2019 Vol. 18, No. 2 358 imperiled species in the Tennessee River system have largely overlooked the Buffalo River’s potential. The present survey recorded 36 species in the main channel of the river and an additional species found a few months before fieldwork began (Margaritifera monodonta). Of these, 29 species were represented by live or freshdead material, and 8 species were represented by relic shells only. There were 14 species present in the historical record that we did not detect. We rarely encountered the degree of species richness or abundance noted in previous studies. In our qualitative survey, 22 species were represented by 10 or fewer live or fresh dead individuals and 7 species were represented by relic shells only. A substantial reach of the Buffalo River had few or no live mussels (BRM 32.0 to 98.2; BRM 105.3 to BRM 122.0). The middle reach from BRM 32.0 to BRM 58.0 contained only L. fasciola and V. taeniata. The paucity of mussels in the middle reach is comparable to the survey data from 1980 (Ahlstedt 1991). Of the 30 species still present in the river, at least 8 species that historically occurred in the upper reaches of the river are now restricted to the lower reaches: Actinonaias ligamentina, Actinonaias pectorosa (Pheasantshell), Lampsilis cardium (Plain Pocketbook), Lampsilis ovata (Pocketbook), Lasmigona costata (Flutedshell), Leptodea fragilis (Fragile Papershell), Obovaria subrotunda, and T. verrucosa. We observed obvious signs of stream-bank instability and significant erosion and siltation, likely due to clearing of riparian vegetation adjacent to agricultural operations, in various stretches of the river. In general, most of these reaches produced low CPUE values. Another factor that may be inhibiting recovery of the mussel communities is elevated levels of toxic metals. Denton (2007) reported high levels of mercury in the tissue of Micropterus dolomieu (Lacepède) (Smallmouth Bass) at BRM 17.7, which prompted TDEC to issue a fish-consumption advisory for the lower Buffalo River extending from BRM 31.6 to the confluence with the Duck River. Naimo (1995) reported that elevated levels of mercury can alter growth, filtration efficiency, enzyme activity, and behavior in freshwater mussels. Gravel dredging and unrestricted livestock access have also destabilized many of the tributaries. We found no mussels in the tributaries except for a single, relic shell of Strophitus undulatus in the Little Buffalo River at mile 4.8. Despite reaches with unstable habitat and heavy sedimentation, the Buffalo River and its tributaries have excellent fish diversity, (C. Saylor, TVA, Knoxville, TN, pers. comm.), and support multiple federally listed fishes including Etheostoma boschungi (Wall and Williams) (Slackwater Darter) and Erimonax monachus (Cope) (Spotfin Chub) (Etnier and Starnes 1993). Analysis of spatial distributions demonstrated several findings of immediate conservation importance. Between BRM 3.2 to BRM 4.9, we found 18 species that occurred nowhere else in the Buffalo River, and a number of species that are apparently restricted to its lower reaches (e.g., Lampsilis cardium, Lampsilis teres [Yellow Sandshell], Obliquaria reflexa [Threehorn Wartyback], Pleurobema cordatum [Ohio Pigtoe], Theliderma cylindrica, Cyclonaias pustulosa, and Quadrula quadrula [Mapleleaf]) have not been reported in the Buffalo River since 1931 (van der Schalie 1973). We documented 5 new records for the drainage in this reach (Margaritifera monodonta, Arcidens confragosus [Rock Pocketbook], Fusconaia Southeastern Naturalist 359 M.P. Reed, G.R. Dinkins, and S.A. Ahlstedt 2019 Vol. 18, No. 2 subrotunda, [Longsolid], Ligumia recta, [Black Sandshell], and Theliderma metanevra [Monkeyface]). With the exception of F. subrotunda, all were reported in the lower Duck River by Schilling and Williams (2002). In addition, the area extending from BRM 100.6 to BRM 102.9 should be re-examined and monitored in the future; BRM 102.9 had populations of both P. barnesiana and P. dolabelloides. We observed evidence of recent recruitment for both species. Habitat at sites in this upper reach appeared excellent, with minimal evidence of disturbance. We found no mussels above BRM 102.9, further increasing the importance of preserving this isolated reach. The continued monitoring and conservation of mussel assemblages identified in this study is vital to future management of mussel resources in the Buffalo River. Fish hosts of threatened and endangered mussels should also be monitored. Quadrat excavations conducted at BRM 3.2 provide a baseline for future quantitative mussel monitoring. Because it is a tributary to the Duck River, the Buffalo River has the potential, with the proper attention and management, to regain much of its lost mussel biodiversity. Sedimentation and channel instability appear to be the primary factors impacting mussel habitat in the river. We strongly recommend that landowners in the Buffalo River drainage be encouraged to implement best management practices. Better management of riparian zones and limiting cattle movements near main-channel mussel habitats could play a pivotal role in mitigating sedimentation and habitat degradation in the Buffalo River. Acknowledgments We thank Larry Wilson for providing financial support for the fieldwork, and Michael McKinney and Jess Jones for assistance with design of the quantitative study. Thanks to Todd Amacker, Robert Eldridge, Meredith Hayes, Kristin Irwin, Drew Mallinak, Josh Peterson, Jackson Sibley, Ashley Slater, and Dan Walker for providing assistance in the field, and to Dinkins Biological Consulting, LLC, the University of Tennessee (UT) Fisheries Laboratory, and the UT Outdoor Program for providing equipment. Thanks to Chuck Howard and the TVA for additional support and insight, and to Susan Lanier, Jeanette Jones, and Craig Phillips for mapping assistance. Museum records were provided by Tim Pearce at Carnegie Museum, and Jamie Smith and Art Bogan at North Carolina State Museum of Natural Sciences. Thanks especially to 3 anonymous reviewers for suggestions that improved this manuscript significantly. Finally, we gratefully acknowledge the Mayberry family for allowing us access to their farm on the lower reach of the Buffalo River on multiple occasions, and for their keen interest in preserving the natural history of the Buffalo River. Literature Cited Ahlstedt, S.A. 1991. Cumberlandian mollusk conservation program. Activity 1: Mussel surveys in six Tennessee Valley streams. Walkerana 5(13):123–160. Ahlstedt, S.A., J.R. Powell, R.S. Butler, M.T. Fagg, S.F. Novak, S.R. Palmer, and P.D. Johnson. 2017. Historical and current examination of freshwater mussels (Bivalvia: Margaritiferidae, Unionidae) in the Duck River Basin, Tennessee. Malacological Review 45/46:163 Bates, J.M. 1962. The impact of impoundment on the mussel fauna of Kentucky Reservoir, Tennessee River. American Midland Naturalist 68(1):232–236. Southeastern Naturalist M.P. Reed, G.R. Dinkins, and S.A. Ahlstedt 2019 Vol. 18, No. 2 360 Boschung, J.T., Jr., and R.L. Mayden. 2004. Fishes of Alabama. Smithsonian Books, Washington, DC. 736 pp. Denton, G.M. 2007. Mercury levels in Tennessee fish. Tennessee Department of Environment and Conservation, Division of Water Pollution Control, Nashville, TN. Etnier, D.A., and W.C. Starnes. 1993. The Fishes of Tennessee. University of Tennessee Press, Knoxville, TN. 696 pp. Fitz, R. 1973. Tennessee Valley streams: Their fish, bottom fauna, and aquatic habitat. Buffalo River Drainage Basin. Division of Forestry, Fisheries and Wildlife Development, Fisheries and Waterfowl Resources Branch. Tennessee Valley Authority, Knoxville, TN. 1973. Garner, J.T., H. Blalock–Herod, A.E. Bogan, R.S. Butler, W.R. Haag, P.D. Hartfield, J.J. Herod, P.D. Johnson, W.W. McGregor, and J.D. Williams. 2004. Freshwater mussels and snails. Pp. 1358, In R.A. Mirarchi (Ed.). Alabama Wildlife. Volume 1. A Checklist of Vertebrates and Selected Invertebrates: Aquatic Mollusks, Fishes, Amphibians, Reptiles, Birds, and Mammals. The University of Alabama Press, Tuscaloosa, AL. 212 pp. Haag, W.R., and R.R. Cicerello. 2016. A distributional atlas of the freshwater mussels of Kentucky. Scientific and Technical Series 8. Kentucky State Nature Preserves Commission, Frankfort, KY. 299 pp. Hornbach, D.J., and T. Deneka. 1996. A comparison of a qualitative and a quantitative collection method for examining freshwater mussel assemblages. Journal of the North American Benthological Society 15(4):587–596. Hubbs, D.W., and A. Jones. 2000. 1998 statewide commercial mussel report. Tennessee Wildlife Resources Agency Fisheries Report 00–08. Nashville, TN. 36 pp. Hubbs, D., S. Chance, L. Colley, and R.S. Butler. 2011. 2010 Duck River quantitative mussel survey. Tennessee Wildlife Resources Agency, Fisheries Division Report 11–04. Nashville, TN. Isom, B.G., and P. Yokley Jr. 1968. The mussel fauna of the Duck River in Tennessee, 1965. American Midland Naturalist 80(1):34–42. Jenkinson, J.J. 1988. Resurvey of freshwater mussel stocks in the Duck River, Tennessee. Tennessee Valley Authority, Knoxville, TN. Johnson, R.I. 1978. Systematics and zoogeography of Plagiola (=Dysnomia = Epioblasma), an almost extinct genus of freshwater mussels (Bivalvia: Unionidae) from Middle North America. Bulletin of the Museum of Comparative Zoology 148(6):239–320. Jones, J.W. 2004. A holistic approach to taxonomic evaluation of two closely related endangered freshwater mussel species, the Oyster Mussel (Epioblasma capsaeformis) and Tan Riffleshell (Epioblasma florentina walkeri). M.Sc. Thesis. Virginia Polytechnic Institute and State University, Blacksburg, VA. Available online at http://scholar.lib.vt.edu/theses/ available/etd–03302004–153127/. Accessed June 2015. Jones, J.W., and R. J. Neves. 2010. Descriptions of a new species and a new subspecies of freshwater mussels, Epioblasma ahlstedti and Epioblasma florentina aureola (Bivalvia: Unionidae), in the Tennessee River drainage, USA. The Nautilus 124:77–92. Mast, M.A., and J.T. Turk. 1999. Environmental characteristics and water quality of hydrologic benchmark network stations in the eastern United States, 1963–95. US Geological Survey Circular 1173(A):158. Miller, A.C., and B.S. Payne. 1993. Qualitative versus quantitative sampling to evaluate population and community characteristics at a large-river mussel bed. American Midland Naturalist 130(1):133–145. Southeastern Naturalist 361 M.P. Reed, G.R. Dinkins, and S.A. Ahlstedt 2019 Vol. 18, No. 2 Miller, A.C., B.S. Payne, D.J. Shafer, and L.T. Neil. 1993. Techniques for monitoring freshwater bivalve communities in large rivers. Pp. 145–158, In K.S. Cummings, B.C. Buchanan, and L.M. Koch (Ed.). Conservation and Management of Freshwater Mussels. Proceedings of a UMRCC Symposium, 12–14 October 1992, St. Louis, MO. Upper Mississippi River Conservation Committee, Rock Island, IL. Naimo, T.J. 1995. A review of the effects of heavy metals on freshwater mussels. Ecotoxicology 4(6):341–362. Obermeyer, B.K. 1998. A comparison of quadrats versus timed snorkel searches for assessing freshwater mussels. American Midland Naturalist 139(2):331–339. Ortmann, A.E. 1924. The naiad-fauna of the Duck River in Tennessee. American Midland Naturalist 9(2):28. Parmalee, P.W., and A.E. Bogan. 1998. The Freshwater Mussels of Tennessee. The University of Tennessee Press, Knoxville, TN. 147 pp. Schilling, E.M., and J.D. Williams. 2002. Freshwater mussels (Bivalvia: Margaritiferidae and Unionidae) of the Lower Duck River in Middle Tennessee: A historic and recent review. Southeastern Naturalist 1(4):403–414. Smalley, G.W. 1981. Classification and evaluation of forest sites on the western Highland Rim and Pennyroyal. General technical Report SO–30, US Department of Agriculture Forest Service, Southern Forest Experiment Station, Asheville, NC. 120 pp. Smirnov, N. 1948. Table for estimating the goodness-of-fit for empirical distributions. Annals of Mathematical Statistics 19:279–281. Stansbery, D.H. 1976. Naiad mollusks. Pp. 42–52, In H.T. Boschung (Ed.). Endangered and Threatened Plants and Animals of Alabama. Alabama Museum of Natural History Bulletin 2. 93 pp. Tennessee Department of Environment and Conservation (TDEC). 2005. Total maximum daily load (TDML) for pathogens in the Buffalo River watershed (HUC 06040004). State of Tennessee, Department of Environment and Conservation, Division of Water Pollution Control, January 2005. Available online at http://www.state.tn.us/environment/ wpc/tmdl/approvedtmdl/BuffaloF2.pdf. Accessed December 2013. US Fish and Wildlife Service (USFWS). 1976. Endangered and threatened wildlife and plants; endangered status for 159 taxa of animals. Federal Register 41:24062–24067. USFWS. 1977. Endangered and threatened wildlife and plants; determination of endangered status for Tan Riffleshell; final rule. Federal Register 42(163):42351–42353. USFWS. 1989. Endangered and threatened wildlife and plants; determination of Cracking Pearlymussel (Hemistena (=Lastena) lata) to be an endangered species. Federal Register 54(187):39850–39863. USFWS. 1997. Endangered and threatened wildlife and plants; determination of endangered status for the Culberland Elktoe, Oyster Mussel, Cumberlandian Combshell, Purple Bean, and Rough Rabbitsfoot; final rule. Federal Register 62(7):1647–1658. USFWS. 2012. Endangered and threatened wildlife and plants; determination of endangered status for the Sheepnose and Spectaclecase mussels throughout their range; final rule. Federal Register 80(83):24691–24774. USFWS. 2013a. Endangered and threatened wildlife and plants; endangered species status for the Fluted Kidneyshell and Slabside Pearlymussel; final rule. Federal Register 78(187): 59269–59287. USFWS. 2013b. Endangered and threatened wildlife and plants; endangered status for the Neosho Mucket and threatened status for the Rabbitsfoot; final rule. Federal Register 78(180):57076–57097. Southeastern Naturalist M.P. Reed, G.R. Dinkins, and S.A. Ahlstedt 2019 Vol. 18, No. 2 362 USFWS. 2015. Endangered and threatened wildlife and plants; designation of critical habitat for Neosho Mucket and Rabbitsfoot; final rule. Federal Register 80(83):24691–24774. van der Schalie, H. 1973. The mollusks of the Duck River drainage in central Tennessee. Sterkiana 52:45–56. Watters, G.T., M.A. Hoggarth, and D.H. Stansbery. 2009. The Freshwater Mussels of Ohio. The Ohio State University Press, Columbus, OH. 421 pp. Williams, J.D., A.E. Bogan, and J.T. Garner. 2008. Freshwater mussels of Alabama and the Mobile Basin. University of Alabama Press, Tuscaloosa, AL. 908 pp. Williams, J.D., A.E. Bogan, R.S. Butler, K.S. Cummings, J.T. Garner, J.L. Harris, N.A. Johnson, and G.T. Watters. 2017. A revised list of the freshwater mussels (Mollusca: Bivalvia: Unionida) of the United States and Canada. Freshwater Mollusk Biology and Conservation 20:33–58. Southeastern Naturalist 363 M.P. Reed, G.R. Dinkins, and S.A. Ahlstedt 2019 Vol. 18, No. 2 Appendix 1. List of mussel species documented in the Buffalo River, by survey year. 1922 = Ortmann (1924), 1931 = Van der Schalie (1973), 1965 = Isom and Yokley (1968), 1980 = Ahlstedt (1991), 2002 = Ahlstedt et al. (2017), and 2011 = TVA field crew (unpubl. data). Present Species 1922 1931 1965 1980 2002 2011 study Margaritiferidae Margaritifera monodonta X Unionidae Actinonaias ligamentina X X X X Actinonaias pectorosa X X X X X Alasmidonta marginata X X Alasmidonta viridis X Amblema plicata X X X X Arcidens confragosus X Cyclonaias pustulosa X X X Cyclonaias tuberculata X X X X X Ellipsaria lineolata X X Elliptio crassidens X X X X X Eurynia dilatata X X X Epioblasma ahlstedti X Epioblasma aureola X Fusconaia subrotunda X Hemistena lata X X Lampsilis cardium X X X Lampsilis fasciola X X X X Lampsilis ovata X X X X X Lampsilis teres X X X Lasmigona complanata X Lasmigona costata X X X X X Leptodea fragilis X X X Ligumia recta X Megalonaias nervosa X Obliquaria reflexa X X Obovaria subrotunda X X X X Pleurobema cordatum X X X Pleurobema oviforme X X X X Pleurobema sintoxia X Pleuronaia barnesiana X X X X Pleuronaia dolabelloides X X X X Potamilus alatus X X X X Ptychobranchus fasciolaris X Ptychobranchus subtentus X Pyganodon grandis X X X X Quadrula quadrula X X Strophitus undulatus X X X Theliderma cylindrica X X Theliderma metanevra X Southeastern Naturalist M.P. Reed, G.R. Dinkins, and S.A. Ahlstedt 2019 Vol. 18, No. 2 364 Present Species 1922 1931 1965 1980 2002 2011 study Toxolasma cylindrellus X Toxolasma lividum X X X Tritogonia verrucosa X X X X Truncilla truncata X X X Utterbackia imbecillis X Villosa iris X X X X X X Villosa taeniata X X X X Villosa vanuxemensis X X X X X X Number of Sites Sampled 1 4 2 24 5 1 62 Total (48 species) 20 31 16 7 8 17 36 Southeastern Naturalist 365 M.P. Reed, G.R. Dinkins, and S.A. Ahlstedt 2019 Vol. 18, No. 2 Appendix 2. Mussel species from the Buffalo River and cataloged at Carnegie Museum of Natural History (CM), University of Tennessee, McClung Museum of Natural History and Culture (UTMM), North Carolina State Museum of Natural Sciences (NCMNS), Museum of Biological Diversity at The Ohio State University (OSUM), and University of Michigan Museum of Zoology (UMMZ). Species CM UTMM NCMNS OSUM UMMZ Actinonaias pectorosa X X X X Alasmidonta marginata X X X Alasmidonta viridis X Amblema plicata X X X Cyclonaias tuberculata X X X X Elliptio crassidens X X Epioblasma ahlstedti X Epioblasma aureola X Epioblasma turgidula X Hemistena lata X Lampsilis cardium X Lampsilis fasciola X X X Lampsilis ovata X X Lasmigona costata X X Ligumia subrostrata X Megalonaias nervosa X Obovaria subrotunda X X X Pleurobema oviforme X X Pleuronaia barnesiana X Pleuronaia dolabelloides X X X Potamilus alatus X Ptychobranchus subtentus X Pyganodon grandis X X Theliderma cylindrica X Strophitus undulatus X Toxolasma cylindrellus X Toxolasma lividum X X Utterbackia imbecillis X Utterbackiana suborbiculata X Villosa iris X X Villosa taeniata X X X Villosa vanuxemensis X X X Number of species 15 9 19 9 6 Number of locations from which 1 6 2 5 4 specimens originated Southeastern Naturalist M.P. Reed, G.R. Dinkins, and S.A. Ahlstedt 2019 Vol. 18, No. 2 366 Appendix 3. Summary of mussels found in the Buffalo River during qualitative collections in 2012–2013, and an opportunistic collection made in 2016 at Buffalo River Mile (BRM) 3.2. Number of live and fresh dead mussels combined; number of relic shells in parentheses and shells collected in 2016 in brackets. Catch-per-unit effort (CPUE) is based on combined number of live and fresh dead found in qualitative sampling only and does not include opportunistic collection. Percent collected (% coll.) is calculated using the combined number of live mussels and dead shells. Species richness is the combined number of live mussels and dead shells. AFederally protected species. BNew drainage record Site 1 2 3 4 5 6 7 8 9 10 11 BRM 0.2 1.9 2.2 2.8 3.2 3.5 4.0 4.6 4.9 6.8 8.0 Species Actinonaias pectorosa (1) Amblema plicata 2 2 (1) (1) Arcidens confragosusB [1] Cyclonaias pustulosa 4 (41) 1 Cyclonaias tuberculata 1 3 (17) 2(2) 2(1) 1 (1) Ellipsaria lineolataB 3 (1) Elliptio crassidens 2 Eurynia dilatata 2 (1) 2(2) (14) (5) 1(1) 1(1) 1(2) Fusconaia subrotundaB (2) Lampsilis cardium 1(1) Lampsilis fasciola 2 1(1) (1) 2(1) (3) 1(2) 1(2) 2(1) 1 Lampsilis ovata 1 (2) 1 Lampsilis teres [1] Lasmigona costata (1) (1) 1 (1) 1 Leptodea fragilis 1 1 (1) Ligumia rectaB (1) Obliquaria reflexa (1) 2 Obovaria subrotunda 1 Pleurobema cordatum (1) Pleurobema oviforme (1) (13) Pleuronaia barnesiana 6 2 1(2) (20) (4) (1) 1 Pleuronaia dolabelloidesA 6 1 2(3) (58) 1(3) (6) 1 Potamilus alatus 1 2(3) 1(1) (1) Pyganodon grandis (1) Quadrula quadrula 1(1) Theliderma cylindricaA 2 6 (1) Theliderma metanevraB [1] Toxolasma lividum 2 1(1) Tritogonia verrucosa 4 1(1) Truncilla truncata 1(4) (10) Villosa iris (1) (1) Villosa taeniata 1(1) Villosa vanuxemensis (1) (1) Effort (person hours) 1.5 1 1 1 1.5 1.5 1 1 1 1 1 Total live and fresh dead 27 1 3 3 34 7 5 6 7 5 0 Total relic 1 1 2 1 21 284 17 16 6 5 1 Southeastern Naturalist 367 M.P. 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Ahlstedt 2019 Vol. 18, No. 2 Site 1 2 3 4 5 6 7 8 9 10 11 BRM 0.2 1.9 2.2 2.8 3.2 3.5 4.0 4.6 4.9 6.8 8.0 CPUE 18 1 3 3 20 4 5 6 7 5 0 Species richness 9 2 3 3 23 18 7 10 9 7 1 Site 12 13 14 15 16 17 18 19 20 21 22 BRM 12.0 13.8 16.3 17.7 19.4 22.4 25.8 32.0 34.3 41.4 42.8 Species Actinonaias pectorosa Amblema plicata (1) Arcidens confragosusB Cyclonaias pustulosa Cyclonaias tuberculata (1) (1) Ellipsaria lineolataB Elliptio crassidens Eurynia dilatata (1) 1 Fusconaia subrotundaB Lampsilis cardium Lampsilis fasciola 2(2) 4(1) 2 2 1 Lampsilis ovata 1 Lampsilis teres Lasmigona costata 1(1) 1 1 Leptodea fragilis 1(1) 1 1 Ligumia rectaB Obliquaria reflexa Obovaria subrotunda Pleurobema cordatum Pleurobema oviforme Pleuronaia barnesiana (2) 1 Pleuronaia dolabelloidesA (1) (2) (3) 1 1 Potamilus alatus 1 2 Pyganodon grandis Quadrula quadrula Theliderma cylindrica 1 Theliderma metanevraB Toxolasma lividum Tritogonia verrucosa 1 1 Truncilla truncata Villosa iris Villosa taeniata 1 1 2 1 2(2) Villosa vanuxemensis Effort (person hours) 1 1 1 1 1 1 1 1 1 1 1 Total live and fresh dead 1 2 5 9 7 6 3 0 0 0 2 Total relic 1 6 5 1 2 2 0 0 0 0 2 CPUE 1 2 5 9 7 6 3 0 0 0 2 Species richness 2 3 3 9 6 7 3 0 0 0 1 Southeastern Naturalist M.P. Reed, G.R. Dinkins, and S.A. Ahlstedt 2019 Vol. 18, No. 2 368 Site 23 24 25 26 27 28 29 30 31 32 33 BRM 45.6 52.1 55.1 55.6 56.0 57.4 58.0 59.0 62.7 67.4 70.6 Species Actinonaias pectorosa Amblema plicata Arcidens confragosusB Cyclonaias pustulosa Cyclonaias tuberculata (1) (1) Ellipsaria lineolataB Elliptio crassidens (1) Eurynia dilatata Fusconaia subrotundaB Lampsilis cardium Lampsilis fasciola 1 (1) 1(2) Lampsilis ovata Lampsilis teres Lasmigona costata Leptodea fragilis Ligumia rectaB Obliquaria reflexa Obovaria subrotunda Pleurobema cordatum Pleurobema oviforme Pleuronaia barnesiana (1) 2 Pleuronaia dolabelloidesA Potamilus alatus 1 Pyganodon grandis Quadrula quadrula Theliderma cylindricaA Theliderma metanevraB Toxolasma lividum Tritogonia verrucosa Truncilla truncata Villosa iris (1) Villosa taeniata (1) 1 1 3(7) (4) (2) 1 (1) 2 Villosa vanuxemensis 1 Effort (person hours) 1 1 1 1 1 1 1 1 1 1 1 Total live and fresh dead 0 0 2 1 3 1 0 2 3 0 2 Total relic 0 1 0 3 8 7 2 0 1 1 0 CPUE 0 0 2 1 3 1 0 2 3 0 2 Species richness 0 1 2 4 2 3 1 2 3 1 1 Southeastern Naturalist 369 M.P. Reed, G.R. Dinkins, and S.A. Ahlstedt 2019 Vol. 18, No. 2 Site 34 35 36 37 38 39 40 41 42 43 BRM 73.5 78.7 80.5 87.0 90.6 93.6 98.2 100.6 102.9 105.3 Species Actinonaias pectorosa Amblema plicata Arcidens confragosusB Cyclonaias pustulosa Cyclonaias tuberculata Ellipsaria lineolataB Elliptio crassidens (1) Eurynia dilatata Fusconaia subrotundaB Lampsilis cardium Lampsilis fasciola 1 1 Lampsilis ovata Lampsilis teres Lasmigona costata Leptodea fragilis Ligumia rectaB Obliquaria reflexa Obovaria subrotunda Pleurobema cordatum Pleurobema oviforme Pleuronaia barnesiana (9) 3(5) 5(3) Pleuronaia dolabelloides1 2 5 Potamilus alatus Pyganodon grandis Quadrula quadrula Theliderma cylindricaA Theliderma metanevraB Toxolasma lividum Tritogonia verrucosa Truncilla truncata Villosa iris Villosa taeniata (3) 3 2 (8) (4) 7(42) 12(13) (5) Villosa vanuxemensis 2 1 Effort (person hours) 1 1 1 1 1 1 1 1 1 1 Total live and fresh dead 0 3 0 2 0 1 0 14 24 0 Total relic 3 1 0 0 0 17 4 47 16 5 CPUE 0 3 0 2 0 1 0 14 24 0 Species richness 1 2 0 1 0 3 1 4 5 1 Southeastern Naturalist M.P. Reed, G.R. Dinkins, and S.A. Ahlstedt 2019 Vol. 18, No. 2 370 Site 44 45 46 47 Site Distrib. % BRM 111.3 116.7 121.0 122.0 Totals freq. (BRM) coll. Species Actinonaias pectorosa (1) 1 3.2 0.2 Amblema plicata 4(3) 5 0.2–22.4 1.1 Arcidens confragosusB 1 1 3.2 0.2 Cyclonaias pustulosa 5(41) 3 3.2–4.9 7.9 Cyclonaias tuberculata 9(25) 10 0.2–57.4 5.9 Ellipsaria lineolataB 3(1) 2 0.2–3.2 0.7 Elliptio crassidens 2(2) 3 0.2–78.7 0.7 Eurynia dilatata 8(27) 10 0.2–22.4 6.0 Fusconaia subrotundaB (2) 1 4.6 0.2 Lampsilis cardium 1(1) 1 0.2 0.4 Lampsilis fasciola 25(17) 19 0.2–102.9 7.3 Lampsilis ovata 3(2) 4 3.2–17.7 0.9 Lampsilis teres 1 1 3.2 0.2 Lasmigona costata 4(4) 8 1.9–25.8 1.6 Leptodea fragilis 5(2) 6 3.5–19.4 1.1 Ligumia rectaB (1) 1 4.6 0.2 Obliquaria reflexa 2(1) 2 3.2–3.5 0.5 Obovaria subrotunda 1 1 3.2 0.2 Pleurobema cordatum (1) 1 3.5 0.2 Pleurobema oviforme (14) 2 3.2–3.5 2.4 Pleuronaia barnesiana 21(47) 14 0.2–102.9 11.2 Pleuronaia dolabelloidesA 20(76) 14 0.3–102.9 16.6 Potamilus alatus 8(5) 7 1.9–59.0 2.2 Pyganodon grandis (1) 1 3.2 0.2 Quadrula quadrula 1(1) 1 3.5 0.4 Theliderma cylindricaA 9(1) 4 2.2–17.7 1.7 Theliderma metanevraB 1 1 3.2 0.2 Toxolasma lividum 3(1) 2 3.2–3.5 0.7 Tritogonia verrucosa 7(1) 4 0.2–22.4 1.4 Truncilla truncata 1(14) 2 3.2–3.5 2.6 Villosa iris (3) 3 4.6–62.7 0.7 Villosa taeniata 40(93) 23 4.9–102.9 22.9 Villosa vanuxemensis 4(2) 5 3.2–102.9 1.0 Effort (person hours) 1 1 1 1 Total live and fresh dead 0 0 0 0 189 Total relic 0 0 0 0 390 CPUE 0 0 0 0 Species richness 0 0 0 0 33 Southeastern Naturalist 371 M.P. Reed, G.R. Dinkins, and S.A. Ahlstedt 2019 Vol. 18, No. 2 Appendix 4. Conservation status of mussels of the Buffalo River, TN. Federal status according to USFWS (2016). Species with Unknown status were either undetected or represented by relic shells only. E = Endangered, T = Threatened, X = Extinct. Status Buffalo Scientific name Common name USFWS River Margaritiferidae Margaritifera monodonta (Say) Spectaclecase E Extant Unionidae Actinonaias ligamentina (Lamarck) Mucket Extant Actinonaias pectorosa (Conrad) Pheasantshell Extant Alasmidonta marginata Say Elktoe Unknown Alasmidonta viridis (Rafinesque) Slippershell Unknown Amblema plicata (Say) Threeridge Extant Arcidens confragosus (Say) Rock Pocketbook Extant Cyclonaias pustulosa (Lea) Pimpleback Extant Cyclonaias tuberculata (Rafinesque) Purple Wartyback Extant Ellipsaria lineolata (Rafinesque) Butterfly Extant Elliptio crassidens (Lamarck) Elephantear Extant Epioblasma ahlstedti Jones and Neves Duck River Dartersnapper E Unknown Epioblasma aureola Jones and Neves Golden Riffleshell E Unknown Epioblasma turgidula (Lea) Turgid Blossom E,X Unknown Eurynia dilatata Rafinesque Spike Extant Fusconaia subrotunda (Lea) Longsolid Unknown Hemistena lata (Rafinesque) Cracking Pearlymussel E Unknown Lampsilis cardium Rafinesque Plain Pocketbook Extant Lampsilis fasciola Rafinesque Wavyrayed Lampmussel Extant Lampsilis ovata (Say) Pocketbook Extant Lampsilis teres (Rafinesque) Yellow Sandshell Extant Lasmigona complanata (Barnes) White Heelsplitter Unknown Lasmigona costata (Rafinesque) Flutedshell Extant Leptodea fragilis (Rafinesque) Fragile Papershell Extant Ligumia recta (Lamarck) Black Sandshell Unknown Ligumia subrostrata (Say) Pondmussel Unknown Megalonaias nervosa (Rafinesque) Washboard Extant Obliquaria reflexa Rafinesque Threehorn Wartyback Extant Obovaria subrotunda (Rafinesque) Round Hickorynut Extant Pleurobema cordatum (Rafinesque) Ohio Pigtoe Unknown Pleurobema oviforme (Conrad) Tennessee Clubshell Unknown Pleurobema sintoxia (Rafinesque) Round Pigtoe Unknown Pleuronaia barnesiana (Lea) Tennessee Pigtoe Extant Pleuronaia dolabelloides (Lea) Slabside Pearlymussel E Extant Potamilus alatus (Say) Pink Heelsplitter Extant Ptychobranchus fasciolaris (Rafinesque) Kidneyshell Unknown Ptychobranchus subtentus (Say) Fluted Kidneyshell E Unknown Pyganodon grandis (Say) Giant Floater Unknown Southeastern Naturalist M.P. Reed, G.R. Dinkins, and S.A. Ahlstedt 2019 Vol. 18, No. 2 372 Status Buffalo Scientific name Common name USFWS River Quadrula quadrula (Rafinesque) Mapleleaf Extant Strophitus undulatus (Say) Creeper Unknown Theliderma cylindrica (Say) Rabbitsfoot T Extant Theliderma metanevra (Rafinesque) Monkeyface Extant Toxolasma cylindrellus (Lea) Pale Lilliput E Unknown Toxolasma lividum Rafinesque Purple Lilliput Extant Tritogonia verrucosa (Rafinesque) Pistolgrip Extant Truncilla truncata Rafinesque Deertoe Extant Utterbackia imbecillis (Say) Paper Pondshell Unknown Utterbackiana suborbiculata (Say) Flat Floater Unknown Villosa iris (Lea) Rainbow Unknown Villosa taeniata (Conrad) Painted Creekshell Extant Villosa vanuxemensis (Lea) Mountain Creekshell Extant Total (51 species)