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The Freshwater Mussels of

Paul W Parmalee and Arthur E. Bogan

Sponsored by American Pearl Farms Environmental Protection Agency Shell Exporters of America, Inc. Tennessee Department of Agriculture Tennessee Wildlife Resources Agency U.S. Department of Agriculture Forest Service U.S. Fish and Wildlife Service

THE UNIVERSITY OF TENNESSEE PRESS / KNOXVILLE Copyright C) 1998 by The University of Tennessee Press / Cover design by Sheila Hart, photographs by W. Miles To Barbara and Cindy Knoxville. Wright. Unless otherwise noted, all photographs in this All Rights Reserved. Manufactured in Canada. volume are by W. Miles Wright. First Edition. Library of Congress Cataloging-in-Publication Data The paper in this book meets the minimum requirements of the American National Standard for Permanence of Parmalee, Paul W. Paper for Printed Library Materials. (j) The binding The freshwater mussels of Tennessee / Paul W. Parmalee materials have been chosen for strength and durability. and Arthur E. Bogan. — 1st ed. p. cm. Includes bibliographical references (p. ) and index. ISBN 1-57233-013-9 (cloth: alk. paper) Many State of Tennessee programs receive federal aid for 1. Freshwater mussels. I. Bogan, Arthur E. II. Title. such wildlife programs as fish and/or wildlife. Policies of QL430.6.P37 1998 the State and regulations of the U.S. Department of the 594' .4—dc21 97-45371 Interior prohibit discrimination on the basis of race, color, religion, national origin, age, sex or handicap. If you be- lieve that you have been discriminated against in any pro- gram, activity, or facility as described above, or if you de- sire more information, please write to the Office of Equal Opportunity, U.S. Department of the Interior, Washington, D.C. 20240.

Status: Currently Stable (Williams et al., 1993:11). Vi- Fusconaia flava var. parvula Grier, 1918; Grier, 1918:11 able populations of the Ebonyshell occur throughout Fusconaia rubiginosa parvula Grier, 1918; Baker, 1922a:19 Fusconaia flava parvula Grier, 1918; Baker, 1924:133 Cumberland River and the middle major stretches of the Quadrula (Fusconaia) flava srunpsoniana Frierson, 1927:55 and lower ( Lake) sections of the Tennessee Fusconaia flava sampsoniana (Frierson,1927); Haas, 1969a:314 River. Excessive harvesting by commercial shellers has Fusconaia undata trigonoides Frierson in Utterback, 1915; had a detrimental effect on some local populations. Utterback, 1915:107, pl. 15, figs. 30a—d; pl. 4, figs. 9a—b Quadrula (Fusconaia) undata trigonoides (Frierson in Utterback, 1915); Frierson, 1927:55 Fusconaia tendata trigonoides (Frierson, 1915); Haas, 1969a:312 Fusconaia undata wagneri Baker, 1928; Bake, 1928a:64-66, Wabash Pigtoe pl. 40, figs. 1-3 RANGE MAP 42; PLATE 43 Synonymy: Type LoCkliky: Small tributaries of Kentucky, Salt, and Quadri!la (Fusconaia) obliqua (Lamarck, 1819); Simpson, Green rivers (Murray and Leonard, 1962). 1900a:788 [in part] a triangular, elevated, deeply serrated pseudocardinal lowish brown, becoming darker in old shells, and hav- Obliquaria flava Rafinesque, 1820; Rafinesque, 1820:305, pl. The entire Mississippi River drain- tooth; the lateral tooth is high and thin, occasionally 81, figs. 13, 14 General Distribution: ing a satinlike gloss. The nacre is whitish, often tinged Unio flavus (Rafinesque, 1820); Conrad, 1837:74 age from western New York to eastern Kansas, Ne- with a second smaller lateral tooth. The interdentum with light pink or salmon; it is iridescent posteriorly. Fusconaia flava (Rafinesque, 1820); Ortmann, 1919:14 braska and South Dakota, south to Texas and Louisi- is fairly wide; the beak cavity is wide and moderately Ortmann (1926a) noted that specimens from the North Fusconaia flava flava (Rafinesque, 1820); Haas, 1969a:313 ana. In Canada it occurs in the Lake Huron, Lake St. deep. The periostracum, typically without rays, is yel- Fork Obion River had a reddish nacre. ? Obliquaria (Sintoxia) lateralis Rafinesque, 1820; Rafinesque, Clair, and Lake Erie drainage basins of Ontario, and 1820:310 in the Red River—Nelson River system of Manitoba Life History and Ecology: Fusconaia flava Unio undatus Barnes, 1823; Barnes, 1823:121, pl. 4, fig. 4 is a species Fusconaja undata (Barnes, 1823); Ortmann, 1912a:241 (Clarke, 1981a). Tombigbee River, . that may be found in medium-sized rivers like the Quadrula (Fusconaia) undata (Barnes, 1823); Simpson, Harpeth at depths of less than three feet, as well as in 1914:880 Tennessee Distribution: Starnes and Bogan (1988) list big rivers such as the Cumberland in water 12 to 15 Fusconaia undata (Barnes, 1823); Ortmann and Walker, 1922:6 Fusconaia /lava as occurring in the Cumberland, Stones, feet deep. A stable substrate composed of coarse sand Fusconaia undata undata (Barnes, 1823); Haas, 1969a:311 Harpeth, Hatchie, and lower Tennessee rivers. For- and gravel appear most suitable for this mussel. Man- Unio rubiginosus Lea, 1829; Lea, 1829:427, pl. 8, fig. 10 Margarita (Unio) rubiginosus (Lea, 1829); Lea, 1836:20 merly present at Union City, North Fork Obion River, ning (1989) collected live specimens in stretches of the Margaron (Unio) rubiginosus (Lea, 1829); Lea, 1852c:24 Obion County (Ortmann, 1926a). Rare in Reelfoot Hatchie River with a firm clay and silt bottom. The Unio rubiginosa Lea, 1829; Deshayes, 1839:672 Lake, Obion County. Wabash Pigtoe is tachytictic, the breeding season last- Unio flavus var. rubiginosus (Lea, 1829); Paetel, 1890:152 ing from May to August. Fuller (1974) lists the white Quadrula rubiginosa (Lea, 1829); Baker, 1898:77, pl. 19, fig. Description: Shells of the Wabash Pigtoe vary in out- crappie (Pomoxis annularis), black crappie (P. nigro- 1, pl. 20, fig. 1 moderately Quadrula (Fusconaia) rubiginosa (Lea, 1829); Simpson, line from quadrate to subtriangular, are maculatus), and bluegill (Lepomis macrochirus) as fish 1900a:786 heavy to thick, and compressed (specimens from the hosts for the glochidia. Fusconaja rubiginosus (Lea, 1829); Ortmann, 1912a:241 Harpeth River) to considerably elevated (Cumberland Unio trigonus Lea, 1831; Lea, 1831:110, pl. 16, fig. 40 River specimens). Mature individuals average about 70 Status: Currently Stable (Williams et al., 1993:11). Margarita (Unio) trigonus (Lea, 1831); Lea, 1836:18 mm in length. Beaks vary from compressed in small to Although adaptable to varying water depths, rates of Margaron (Unio) trigonus (Lea, 1831); Lea, 1852c:25 full, and considerably el- flow and substrate composition, Quadrula trigona (Lea, 1831); Baker, 1898:76, pl. 15, fig. 5 medium-sized rivers to high, populations of Fus- Quadrula (Fusconaia) trigona (Lea, 1831); Simpson, evated in big rivers; sculpture consists of 3-5 nearly conaia flava in Tennessee appear local, and, but for a 1900a:787 concentric bars that form an angle on the posterior few exceptions, the number of individuals is low. Fusconaia undata trigona (Lea, 1831); Grier and Mueller, ridge. The anterior end is rounded, the dorsal margin 1926:16, 32 is squared, and the posterior end is obliquely truncated. Quadrula (Fusconaia) undata trigona (Lea, 1831); Frierson, Fusconaia subrotunda (Lea, 1831) The dorsal ridge is distinct but with a sloping angle; a 1927:54 Longsolid Unio triangularis Say, 1834; Mister, 1852:56, pl. 12, fig. 3 wide, shallow depression is usually present anterior to [misidentification] the posterior ridge. The surface is often marked with RANGE MAP 43; PLATE 44 Unio pilaris Lea, 1840; Reeve, 1865:pl. 27, fig. 138 [misiden- growth lines that are occasionally raised and form Synonymy: tification] slight ridges. ? Unio brevialis Lamarck, 1819; Crouch, 1827:16, pl. 9, fig. 3 1914; Wheeler, 1914:76, pl. 4 [misidentification] Fusconaia selecta Wheeler, The left valve has two elevated, triangular, serrated, Quadrula (Fusconaia) undata selecta (Wheeler, 1914); Unio subrotundus Lea, 1831; Lea, 1831:117, pl. 18, fig. 454 Frierson, 1927:55 divergent pseudocardinal teeth; the two lateral teeth Margarita (Unio) subrotundus (Lea, 1831); Lea, 1836:34 Fusconaia undata selecta Wheeler, 1914; Haas, 1969a:312 are thin, high, and nearly straight. The right valve has Margaron (Unio) subrotundus (Lea, 1831); Lea, 1852c:35

Quadrula (Fusconaia) subrotunda (Lea, 1831); Simpson, Type Locality: Fusconaia subrotunda, ; F. pilaris, 1900a:791 French Broad and Holston rivers, Tennessee; E p. lesueur- Quadrula subrotunda (Lea, 1831); Sterki, 1907:391 iana, Caney Fork and Holston rivers, Tennessee; F. subrotunda (Lea, 1831); Ortmann, 1912a:294 Fusconaja River, Virginia. Fusconaia subrotunda (Lea, 1831); Ortmann, 1919:7, pl. 1, bursa-pastoris, Powell fig. 2 Unio kirtlandianus Lea, 1834; Lea, 1834:98, pl. 14, fig. 41 General Distribution: Ohio, Cumberland, and Tennes- Margarita (Unio) kirtlandianus (Lea, 1834); Lea, 1836:34 see River systems (Simpson, 1914:893). Unio kirklandianus Lea, 1834; Hanley, 1842a:203 [misspelling] (Unio) kirtlandianus (Lea, 1834); Lea, 1852c:35 . Margaron Tennessee Distribution: Considering the several sub- Quadrula (Fusconaia) kirtlandianus (Lea, 1834); Simpson, 1900a:791 species or varieties of the Longsolid as one taxon, Fus- Quadrula kirtlandianus (Lea, 1834); Sterki, 1907:391 conaia subrotunda, it is listed by Starnes and Bogan Range Map 43. Fusconaia subrotunda (Lea, 1831), Longsolid. Fusconaja kirtlandiana (Lea, 1834); Ortmann, 1912a:245-.. (1988) as occurring in the Clinch, Powell, Little Ten- Quadrula (Fusconaia) kirtlandiana (Lea, 1834); Simpson, nessee (now extirpated), Elk, lower Tennessee, and 1914:891 Cumberland rivers, and prior to 1960 it was known docardinal tooth usually with a low tooth or rough- Fusconaia kirtlandiana (Lea, 1834); F. C. Baker, 1928a:136 usually wide, and the beak cavity is deep and some- from the French Broad, Holston, middle and upper ened area on either side. The lateral tooth is broad, Fusconaia subrotunda kirtlandiana (Lea, 1834); Ortmann, what compressed. The periostracurn is a dull straw 1919:11-14, pl. 1, figs. 3-5 Tennessee, and Obey rivers. Occasional specimens may serrated, and often doubled for most of its length. yellow to greenish brown, becoming blackish in old Unio personatus Conrad, 1834 non Say, 1829; Conrad, 1834a:71 still be found in the Holston River, Knox and Grainger Muscle scars are deeply impressed, the interdentum is individuals. Some may show subtle green rays, prima- Unio politus Say, 1834; Say, 1834:no pagination counties. It was formerly fairly common in the Tellico rily on 1842b:195, the umbos. The nacre is pearly white and iri- Unio lesueurianus Lea, 1840; Lea, 1840:286; Lea, River, Monroe County (Parmalee and Klippel, 1984), pl. 8, fig. 6 descent posteriorly. mussel in a short Margaron (Unio) lesueurianus (Lea, 1840); Lea, 1852c:35 and there is a small population of this stretch of the Hiwassee River, Polk County (Parmalee Fusconaia pilaris lesueuriana (Lea, 1840); Ortmann, 1918:528 Life History and Ecology: The small to medium-sized Unio pilaris Lea, 1840; Lea, 1840:285; Lea, 1842b:209, pl. Hughes, 1994). and river forms of Fusconaia subrotunda typically are 14, fig. 24 found in current, usually in riffle areas, at a depth of less than Margaron (Unio) pilaris (Lea, 1840); Lea, 1852c:35 Description: The big river form of Fusconaia subro- Quadrula (Fusconaia) pilaris (Lea, 1840); Simpson, 1900a:792 two feet. The big river form, such as the one inhabiting has a shell that is oval to broadly elliptical or Fusconaia pilaris (Lea, 1840); Ortmann, 1918:527 tunda the Tennessee and Cumberland River reservoirs, may live outline, solid, and inflated. Beaks are high, full, Unio globatus Lea, 1871; Lea, 1871:191; Lea, 1874:5, pl. 1, oblong in at depths of 12-18 feet, in current, and on a sand and over the lunule; sculpture consists fig. 1 and turned forward gravel substrate. The Longsolid, like other species of Quadrula (Fusconaia) globata (Lea, 1871); Simpson, 1900a:793 The anterior mar- of a few subnodular ridges or wrinkles. Fusconaia for which the breeding season is known, is Unio bursa-pastoris B. H. Wright, 1896; B. H. Wright, and posterior gin is broadly rounded, and the ventral probably tachytictic, the females becoming gravid dur- 1896:133, pl. 3 are slightly curved to nearly straight; lacking a Fusconaja bursapastoris (B. H. Wright, 1896); Ortmann, margins ing the summer. Host fish for glochidia unknown. 1913a:90-91 distinct posterior ridge, the dorsal slope is evenly curved. wide, Quadrula (Fusconaia) bursa-pastoris (B. H. Wright, 1896); The shell surface is generally sculptured with low, Status: Special Concern (Williams et al., 1993:11). Com- Simpson, 1900a:791 concentric ridges. Mature individuals may reach a length mercial shellers working the Cumberland and lower Ten- Fusconaia pilaris bursa-pastoris (B. H. Wright, 1896); of 100 mm. Shells of the medium-sized to small river nessee (Kentucky Lake) River reservoirs occasionally Ortmann, 1918:529 forms, Unio pilaris and Unio lesueurianus, are more con- Fusconaia bursapastoris (B. H. Wright, 1896); Haas, 1969a:316 encounter individuals of the big river form of Fus- Quadrula flexuosa Simpson, 1900; Simpson, 1900b:83, pl. 2, sistently oval in shape, compressed to only moderately conaia subrotunda, but it appears to be uncommon. In fig. 8 inflated, rayed (especially in juveniles), and olive yel- Kentucky, Cicerello et al. (1991:118) record it as "spo- Quadrula (Fusconaia) kirtlandiana var. minor Simpson, 1900; low to light brown in color with a satinlike appear- radic and rare in the Tennessee, upper Green, Licking, 1900a:791 Simpson, ance. As Ortmann (1918:528) noted when discussing and Big Sandy rivers." Populations of medium-sized Quadrula andrewsii Marsh, 1902; Marsh, 1902a:115 mussels of the upper Tennessee River drainage, "The andrewsae Marsh, 1902; Marsh 19026:8, pl. 1, and small river forms, such as those found in the up- Quadrula lo- upper two figs. [unjustified emendation] typical form of F. pilaris passes into the following per Powell and Clinch rivers, have remained stable and Quadrula (Fusconaia) andrewsii Marsh, 1902; Simpson, cal races [F. p. lesueuriana and F. p. bursa-pastoris, the viable. Elsewhere in similar river habitats, such as the 1914:895 compressed headwaters form] in an upstream direc- Hiwassee, it is very localized and uncommon. Quadrula beauchampii Marsh, 1902; Marsh, 1902b:7, pl. 1, tion, and it is hard to draw a line between them." lower two figs. The left valve has two low, heavy triangular pseu- (Fusconaia) beauchampii Marsh, 1902; Simpson, Quadrula separated with deep striations; 1914:895 docardinal teeth, widely Fusconaja subrotunda var. leucogona Ortmann, 1913; Ortmann, the two lateral teeth are moderately long and straight. Plate 44. 1913b:89-90 The right valve has a heavy, triangular serrated pseu- Fusconaia subrotunda (Lea, 1831), Longsolid.

120 Accounts of Species Family 121

The authors obtained one fresh specimen (1973) from August to June (Baker, 1928a). Watters (1994a) 1937). Ortmann (1909a; 1912a) observed gravid females with old, stunted individual from the lower lists the shovelnose sturgeon (Scaphirhynchus platoryn- of an extremely eggs in late August and gravid females with glochidia River, Knox County. Van der Schalie (1939) chus) as the fish host for glochidia of olivaria. Holston in September. Host fish for the Ringpink unknown. collected the Ringpink from the Tennessee River in counties and the authors more Status: Currently Stable (Williams et al., 1993:13). The Hardin and Humphreys Status: Endangered (Williams et al., 1993:13). The U.S. fresh adult specimens of Hickorynut is presently extremely rare in the Tennes- recently (1980-1990) found Fish and Wildlife Service has developed a recovery plan cull piles taken below Pick- see River and possibly may be extirpated there. the Ringpink in shellers' for this species (U.S. Fish and Wildlife Service, 1991b). wick Landing Dam, Hardin County. Live specimens were reported from that stretch of river by TVA divers (Lamarck, 1819) in 1987. Marsh (1885) and Ortmann (1924a) recorded (Rafinesque, 1820) Ringpink O. retusa from the Duck River, Maury County. Obo- Round Hickorynut fprmerly inhabited the Cumberland River RANGE MAP 73; PLATE RANGE MAP 72; PLATE 73 varia raw 74 County downriver to Stewart County Synonymy: Synonymy: from Jackson Obliquaria (Rotundaria) Unio retusa Lamarck, 1819; Lamarck, 1819:72 (Wilson and Clark, 1914). Recovery of three specimens subrotunda Rafinesque, 1820; Rafinesque, 1820:308, pl. Unió retusus Lamarck, 1819; Conrad, 1836:19, pl. 8 from shellers' cull piles below Hartsville, Trousdale 81, figs. 21-23 Obovaria subrotunda Obovaria torsa Rafinesque, 1820; Rafinesque, 1820:311, pl. an extant population may still sur- (Rafinesque, 1820); Vanatta, 191.5:552; County, indicates Ortmann and Walker, 82, figs. 1-3 and 1922:45 vive in the middle Cumberland River (Parmalee Obovaria (Obovaria) subrotunda Unio torsus (Rafinesque, 1820); Potiez and Michaud, 1844:149, (Rafinesque, 1820); Ortmann, Klippel, 1982). 018:567 pl. 57, figs. 1, 2 Unio (Aximedia) levigata Margarita (Unio) retusus (Lamarck, 1819); Lea, 1836:34 Rafinesque, 1820; Rafinesque, 1820:296, pl. 80, fig. Margaron (Unio) retusus (Lamarck, 1819); Lea, 1852c:35 Description: The shells of Obovaria retusa are inflated, 11 Unio laevigatus Rafinesque, Obovaria (Obovaria) retusa (Lamarck, 1819); Sirnpson, quadrate in outline. The 1820; Say, 1834: no pagination solid, and thick and ovate to [misspelling] 1900a:599 The ventral and posterior margins are evenly rounded. Obovaria levigata (Rafinesque, Obovaria retusa (Lamarck, 1819); Marsh, 1885:6 1820); Vanatta, 1915:552 posterior ridge in male shells is low and rounded. The Obovaria (Obovaria) levigata (Rafinesque, 1820); Haas, pos- 1969a:422 (1819) erroneously gave the female shell has a pronounced groove behind the Type Locality: Lamarck Obovaria corrected terior ridge, making it more distinct; the marsupial area (Obovaria) subrotunda levigata (Rafinesque, 1820); type locality as Nova Scotia. Johnson (1969) Ortmann, 1918:568 is slightly more inflated. Beaks are swollen and high this and designated the type locality as the Ohio River Obovaria subrotunda levigata (Rafinesque, over a lunule; sculpture consists 1820); La Rocque, at Cincinnati, Ohio. and turned forward 1967:242 shell of this Plate 73. Obovaria of a few weak double-looped ridges. The retusa (Lamarck, 1819), Ringpink. Obovaria striata Rafinesque, 1820; Rafinesque, 1820:311 reaching a maximum Vanatta, 1915:552 Distribution: The Ringpink was found through- species may become quite large, General Mya rotunda Wood, River sys- length of about 95 mm in old relic individuals. Ma- cardinal tooth, often with a smaller tooth before and 1856; Wood, 1856:199, pl. 1 supp. fig. 1 out the Ohio, Tennessee, and Cumberland [misspelling] tributaries. ture female shells are only slightly smaller than those behind. It is separated from a single heavy, slightly tems, including many of the major Unio circulus Lea, 1829; Lea, 1829:433, pl. 9, fig 14 males. curved lateral tooth by a short interdentum. of The beak Margarita (Unio) circulus (Lea,1829); Lea, 1836:33 heavy, triangular, sculptured cavity is deep and Tennessee Distribution: The Ringpink has been reported The left valve has two compressed. A series of prominent Margaron (Unio) circulus (Lea, 1829); Lea, 1852c:34 separated from two short heavy, dorsal scars are located under Unio subrotundus var. circulus from the lower Holston River, Knox County, the Ten- pseudocardinal teeth the pseudocardinal teeth. Lea, 1829; Paetel, 1890:168 wide interdentum. The Muscle scars are small Obovaria circulus (Lea, 1829); Simpson, 1900a:600 River at Knoxville, and the Clinch River at curved, lateral teeth by a short, but deep; the pallial line is well nessee Obovaria circula (Lea, 1829); Baker, 1920:383 1918; Hickman, right valve has one large triangular, sculptured pseudo- impressed. The periostracum is shiny, lacking rays, and Clinton, Anderson County (Ortmann, Unio lens Lea, 1831; Lea, 1831:80, pl. 8, fig. 10 yellowish green to brown in color, becoming dark brown Margarita (Unio) lens (Lea, 1831); Lea, 1836:33 to black in old individuals. REEIFOOTIAMM The surface of the shell is Margaron (Unio) lens (Lea, 1831); Lea, 1852c:34 marked by low, irregular, concentric growth lines. The Obovaria lens (Lea, 1831); Simpson, 1900a:600 nacre color within the pallial line is a light pinkish Obovaria subrotunda lens (Lea, 1831); Goodrich and van der Schalie, salrnon to deep purple, while the nacre outside the pal- 1944:318 lial line is Unio leibii Lea, 1862; Lea, 1862:168; Lea, 1866:44, pl. 15, white with a slight iridescence posteriorly. fig. 42 Margaron (Unio) leibii (Lea, 1862); Lea, 1870:36 Life History and Ecology: The Ringpink is typically a Obovaria leibii (Lea, 1862); Simpson, 1900a:601 large river species inhabiting gravel bars (Neel and Allen, Obovaria circulus leibii (Lea, 1862); Sterki, 1907:390 Obovaria 1964). Hickman (1937) collected it in the Tennessee subrotunda leibii (Lea, 1862); Goodrich, 1932:103 Unio depygis Conrad, 1866; Conrad, 1866a:107, River from a gravel and sandy bottom in about two feet pl. 10, fig. 1 Obovaria lens var. depygis (Conrad, 1866); Simpson, of water. Obovaria retusa is Range Map 72. Obovaria retusa (Lamarck, 1819), Ringpink. bradytictic (Surber, 1912). 1900a:601

166 Accounts of Species Family Unionidae 167

Frierson, 1927:90 massive, serrated triangular pseudocardinal tooth, usu- Type Locality: Stones Obovaria subrotunda depygis (Conrad, 1866); River, Tennessee (Lea, 18 parva Simpson, 1914; Simpson, 1914:294 ally with a small, low, compressed tubercular Obovaria lens var. tooth on Cumberland River, Tennessee (Simpson, 1914). Obovaria lens var. elongate Simpson, 1914; Simpson, either side. There is one short, curved, thick, roughened 1914:294-295 lateral tooth, often with a secondary inner low, incom- General Distribution: Tennessee subrotunda globule Morrison, 1942; Morrison, and Cumberland Ri Obovaria plete lateral tooth. Adductor muscle scars are distinct systems, formerly widespread 1942:360; Johnson, (1975:29, pl. 1, fig. 7). from southern Kentu and rather deeply impressed. The Quadrula subrotunda globule (Morrison, 1942); Johnson, interdentum is nar- (Rockcastle County) and southwestern Virginia ( row or absent. The pallial line is 1980:96 impressed. The peri- Russell, Smyth, Tazewell, and Washington countt ostracum is greenish olive to dark brown, sometimes through the tributary stream system of the Tennes Type Locality: "l'Ohio." becoming blackish in old individuals. The posterior and Cumberland rivers in East Tennessee and sou dorsal surface is marked by a distinct, lighter, yellow- west to Lauderdale County, Alabama (Ortmann, 19 General Distribution: Obovaria subrotunda is found ish streak or band; some young shells exhibit faint the Tennessee and Cumberland River sys- throughout greenish rays but most are rayless. The nacre color is Tennessee Distribution: Pegias fabula has been collec Ohio River system from western Penn- tems and in the silvery white and iridescent posteriorly; some speci- from the Collins River in Warren County, in Cane Cre/ and peninsular Michigan west to eastern Illi- sylvania mens have pink to purple shades inside the pallial line. a tributary to the Caney Fork River (Ahlstedt, 198( (1981a) lists the Round Hickorynut from nois. Clarke and in Buck Creek and the Stones River, all in the Cut and Lake St. Clair and their drainages in Lake Erie Life History and Ecology: Ortrnann (1919) repOrted this berland River drainage. Stansbery (1973; 1976a) I Ontario, Canada. species to be bradytictic with eggs present in September ported the Littlewing Pearlymussel from the upper u and glochidia in June. The Round Hickorynut is found impounded reaches of the Clinch River. It has been foul Round Hickorynut was Tennessee Distribution: The in medium-sized to large rivers with sand and gravel sub- in the South Fork Holston Rive; Sullivan County, al and Cumberland River found throughout the Tennessee strates with moderate flow, usually at depths of less than in the Elk Rive; Franklin County (Ortmann, 1918; 192.! systems in Tennessee. In the Tennessee River system, six feet. Host fish for the Round Hickorynut unknown. Holston, Pigeon, it was found in the Powell, Clinch, Description: The Littlewing Pearlymussel is a small sp Buffalo, and Duck Little Tennessee, Sequatchie, Elk, Status: Special Concern (Williams et al., 1993:13). cies: adults rarely. exceed 35 mm in length. Valves a Tennessee rivers as well as the main channel of the thickened anteriorly with a sharp posterior ridge, from River. However, it has disappeared, or nearly so, front of which is a wide radial depression that ends in system Pegias fabula (Lea, 1838) most of these rivers. In the Cumberland River basal sinus. There is another ridge above the posteril rivers (Rafinesque, 1820), Round it occurs in the Obey, Stones, Harpeth, and Red Plate 74. Obovaria subrotunda Littlewing Pearlymussel ridge, making the shell decidedly biangulate and tru Hickorynut. and in the mainstem of the Cumberland River. RANGE MAP 74; PLATE 75 cate behind. Valves of the female possess a wider post Synonymy: rior slope behind the ridge and a more truncated po out- sists of 4-5 weak bars, which are slightly sinuous cen- Description: The shell is elliptical to circular in Margarita (Margaritana) fabula Lea, 1836; Lea, 1836:46 terior end than do those of the male. Beak sculpturit trally and angled posteriorly. The beak cavity is mod- [nomen nudtrinl line, solid, becoming inflated and heavy with age. Maxi- consists of heavy, subconcentric ridges, these beir muscle scars partially in the Margaritana fabula Lea, 1838; Lea, mum shell length rarely exceeds 60 mm. All shell mar- erately deep with dorsal 18386:44, pl. 13, fig. 39 Unio fabida (Lea, 1838); most prominent and persistent on the posterior ridge although the posterior margin in cavity and partially up on the edge of the hingeplate. Hanley, 1843:213, pl. 22, fig. 45 gins are rounded, Margaron (Margaritana) fabula (Lea, 1838); Lea, 1852c:44 The left valve has an irregular triangular pseucl4 lacking. The left valve has two short, thick, roughened, tri-. females may be blunt. The posterior ridge is Microinya fabula (Lea, 1838); Agassiz, 1852:47 cardinal tooth under the beak, sometimes with a ve angular pseudocardinal teeth and two slightly curved, Beaks are centrally placed, full, high, curved inward, Strophitus fabula (Lea, 1838); Conrad, 1853:2.63 tige of another in front of it. Lateral teeth appear ; strong lateral teeth. The right valve has one large, 11aphia and elevated well above the hinge line; sculpture con- short, fabula (Lea, 1838); H. and A. Adams, 1858:499 short, faint, irregular ridges. The right valve has Pegias fabula (Lea, 1838); Simpson, 1900a:660 single triangular tooth in front of tl Alasinidonta fabula (Lea, 1838); Ortmann, 1913a:311 pseudocardinal Alasmidonta (Pegias) tabula (Lea, 1838); Ortmann, 1914:65 beak. Beak cavities are rather deep and compressecli Margaritana curreyiana Lea, 1840; Lea, 1840:288; Lea, anterior muscle scars are deeply impressed. The per i 184213:223, pl. 18, fig. 40 ostracum is usually eroded away in mature indivich Microniya curreyiana (Lea, 1840); Agassiz, 1852:47 als; a few dark brownish or olive green rays are ap- Margaron (Margaritana) curreyiana (Lea, 1840); Lea, 1852c:42 parent along the shell in young specimens: Stropbitus curreyiana (Lea, base of the 1840); Conrad, 1853:263 flesh- Baphia curreyiana (Lea, 1840); H. and A. Adams, 1858:499 The nacre is whitish on the anterior ventral third, Unio curreyiana (Lea, 1840); Sowerby, 1868:pl. 63, fig. 319 colored or salmon in the beak cavities. The shells e) Una° curreyianus (Lea, 1840); Hanley, 1856:386, pl. 24, fig. 10 hibit sexual dimorphism, one of the characters whic h Margaritana curreyiana Lea, 1840; Paetel, 1890:173 separates Pegias from species belonging to the geni s thfio propecaelat7 D e Gregorio, 1914; De Gregorio, Alasmidonta (Simpson, 1900a, 1914; Stansbery, 1976b). l, 14 m, pl. 8 figs. l a_d Range Map 73. Obovaria subrotunda (Rafinesque, 1820), Round Hickorynut.

Unionidae 16 168 Accounts of Species Family

1991b). The U.S. Fish and Wildlife Service has devel- oped a recovery plan for this species (U.S. Fish and Wildlife Service, 1984f) and has created a watershed implementation schedule for the recovery plan (U.S. Fish and Wildlife Service, 1989b).

Toxolasma lividus Rafinesque, 1831 Purple Lilliput RANGE MAP 113; PLATE 114 Synonymy: Range Map 113. Toxolasma lividus Rafinesque, 'Toolasma lividus Rafinesque, 1831; Rafinesque, 1831:2 1831, Purple Lilliput. Toxolasma livida Rafinesque, 1831; Morrison, 1969:24 Toxolasma lividum Rafinesque, 1831; Ortmann, 1918:573 lividum Rafinesque, 1831; Stansbery, Cumberland River system in Tennessee it occurred in Toxolasma lividum sized rivers in mud, sand, and gravel substrates. This 1972:46 the Caney Fork, Stones, and Harpeth rivers and nu- species has also been found on shallow, Rafinesque, 1831; Stansbery, 1976a:48 rocky gravel Toxolasma lividus lividus merous tributary creeks. points or sandbars in Wheeler Unio glans Lea, 1831; Lea, 1831:82, pl. 18, fig. 12 Reservoir, Alabama. Margarita (Unio) glans (Lea, 1831); Lea, 1836:28 Ortmann (1921) reported gravid females in May and Description: The Purple Lilliput is Margaron (Unio) glans (Lea, 1831); Lea, 1852c:31 short, solid, inflated, July. Watters (1994a) listed the green sunfish (Lepo- and elliptical in outline, with Lampsilis (Carunculina) glans (Lea, 1831); Simpson, 1900a:565 a distinct lunule. Shell mis cyanellus) and longear sunfish (L. megalotis) as fish Eurynia (Carunculina) glans (Lea, 1831); Ortmann, 1912a:339 length seldom exceeds 35 mm. The anterior end is uni- hosts for the glochidia of Toxolasma lividus. Cartmculina glans (Lea, 1831); Ortmann, 1910:119 formly rounded; the dorsal margin is nearly straight; glans (Lea, 1831); Stansbery, 1970:18 Carunculina glans the ventral margin is straight; the posterior margin has Status: glans (Lea, 1831); Valentine and Stansbery, 1971:29 Special Concern (Williams et al., 1993:14). Toxolasma a sharp point above and is broadly Toxolasma glans glans (Lea, 1831); Stansbery, 1971:14 rounded below. The cylindrellus (Lea, 1868), Pale Lilliput, Plate 113. Toxolasma Toxolasma lividus glans (Lea, 1831); Stansbery, 1976a:48 posterior ridge is low and rounded. The male shell is Unio moestus Lea, 1841; Lea, 1841b:82; Lea, 1842b:244, pl. short and elliptical to almost rhomboidal in outline be distinguished from closely related species by the 26, fig. 60 with a bluntly rounded posterior margin. The female elongate elliptical shell, yellowish periostracum, a usu- Margaron (Unio) moestus (Lea, 1841); Lea, 1852c:31 shells are shorter and somewhat more inflated and (Lea, 1841); Simpson, 1900a:565 overall, and the even lighter Lampsilis moestus have an angular marsupial swelling ally lighter colored nacre moesta (Lea, 1841); Simpson, 1914:156 at the posterior Lampsilis ventral shade of the nacre outside the pallial line. Where Toxo- Carunculina moesta (Lea, 1841); Ortmann, 1921:89 margin. Beaks are full and elevated; sculpture lasma lividus and T. cylindrellus occur together, T. Carunculina glans moesta (Lea, 1841); Stansbery, 1970:18 consists of irregular ridges which curve upward behind cylindrellus is faster growing and reaches a larger size and become nodulous at the posterior ridge. The beak (Ortmann, 1924a; Stansbery, 1976c). Stansbery (1976c) Type Locality: Rockcastle River [Kentucky]. cavity is open and shallow, and the interdentum is nar- found Toxolasma cylindrellus and Toxolasma lividus row or absent. living together in the Paint Rock River, Alabama. General Distribution: The Purple Lilliput is known The left valve has two erect, triangular, compressed from the Ohio River Basin west of , in- pseudocardinal teeth and two long, nearly straight lat- Life History and Ecology: This tiny naiad is found only cluding Ohio, Michigan, , , and Ken- eral teeth. The right valve has a large elongate pseu- in small tributary rivers and streams of the Tennessee tucky. It occurred in the Tennessee and Cumberland docardinal tooth, often with a vestige of another above, River. The genus is bradytictic, but no other specific River drainages in Tennessee, Virginia, and Kentucky. and a long lateral tooth often with a vestigial lateral data on the host fish or life history was encountered. Oesch (1984) reported the Purple Lilliput from streams or small shelf below it. Adductor muscle scars are im- It may be found in a gravel and sand substrate, slow to in southern Missouri. Also known from the Arkansas pressed; the pallial line is impressed anteriorly. The moderate current, and in less than three feet of water. River in Arkansas and Oklahoma. periostracum has irregular growth lines; color varies from dark brown to black and is rayless. The nacre Status: Endangered (Williams et al., 1993:14). Big Rock Tennessee Distribution: Toxolasma lividus was found color is usually a deep purple, lighter beyond the pal- Creek, a tributary to the Duck River (Marshall County), throughout the upper Tennessee River system, includ- hal line, but sometimes it is a creamy white, becom- appears to be one of the few creeks, if not the only one, ing the Powell, Clinch, Emory, Holston, French Broad, ing iridescent posteriorly. the still supporting a population of this mussel in Tennes- Tellico, Little Pigeon, and Little rivers, as well as ille. Life see. It is known to still occur in the Paint Rock River main channel of the Tennessee River below Knoxv History and Ecology: Ahlstedt (in Neves, 1991) and Elk rivers. In the reported and Hurricane Creek in northern Alabama (Ahlstedt, It was also found in the Duck the Purple Lilliput from small to medium- Plate 114. Toxolasma lividus Rafinesque, 1831, Purple Lilliput.

230 Accounts of Species Family Unionidae 231