Workbook and Key
to the
Freshwater Bivalves
of
North Carolina
Arthur E. Bogan North Carolina Museum of Natural Sciences
Workbook Sponsors
North Carolina Museum of Natural Sciences
North Carolina State University
North Carolina Cooperative Extension Service
North Carolina Wildlife Resources Commission
North Carolina Department of Transportation
North Carolina Freshwater Mussel Conservation Partnership
2002 Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina i
Acknowledgments
I wish to thank the North Carolina Department of Transportation for funding the workshop that initiated this workbook. V. Charles Bruton, Phil Harris, Tim Savidge and Topsy Skinner, all of NCDOT, are gratefully acknowledged for all of their assistance and patience in pulling this workshop together. Tim Savidge initiated the idea of the workshop and has been instrumental in facilitating its occurrence. Mrs. W.T. Edmondson is thanked for granting permission to reproduce figures of her late husband’s second edition of Ward and Whipple, Freshwater Biology. Jonathan Raine greatly assisted in the development of the color plates. Wendy Lovelady, Exhibits Department of the NCSM, assisted and trained me with the scanning of slides and the final printing of the color plates. John M. Alderman, Judith A. Johnson and Brian T. Watson of the NC Wildlife Resources Commission prepared tables 2 and 3. John Alderman and Tim Savidge, NC Department of Transportation both reviewed and expanded the information on the distribution of species in North Carolina. Paul Parmalee is thanked for permitting the use of the color slides reproduced from The Freshwater Mussels of Tennessee (Parmalee and Bogan, 1998). Cindy Bogan once again has been patient in teaching me some of the finer points of the use of Word and has helped format the whole workbook. Valeria Rice, NCSM, has patiently assisted with the preparation of materials and specimens for this workshop. Ian Bogan assisted with the photography and Sean Bogan assisted with the reformatting of two tables. A special financial allocation from the North Carolina Cooperative Extension Service, Renewable Resources Extension Act Funds to Greg Cope, Arthur Bogan, John Alderman and Tim Savidge funded the reproduction costs of this workbook. This is a product of the NC Museum of Natural Sciences, NC State University, NC Cooperative Extension Service, NC Wildlife Resources Commission, NC Department of Transportation, and the NC Freshwater Mussel Conservation Partnership.
Contact Information for the Workbook Distribution:
Dr. W. Gregory Cope, Department of Environmental and Molecular Toxicology, North Carolina State University, Box 7633, Raleigh, NC 27695-7633 919-515-5296 (phone); 919-515-7169 (fax); email: greg_cope@ncsu.edu
Contact Information for Technical Questions:
Dr. Arthur E. Bogan, North Carolina State Museum of Natural Sciences, Research Laboratory, 4301 Reedy Creek Road, Raleigh, NC 27607 919-733-7450 ext 753 (phone); 919-715-2294 (fax); email: arthur.bogan@ncmail.net
Citation for this publication Bogan, A.E. 2002. Workbook and key to the freshwater bivalves of North Carolina. North Carolina Freshwater Mussel Conservation Partnership, Raleigh, NC 101 pp, 10 color plates.Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina ii
Table of Contents
Page
Key to the freshwater bivalves of North Carolina ...............................................................4
Species Accounts:
Corbiculidae......................................................................................................................18
Unionidae..........................................................................................................................19
Glossary .............................................................................................................................88
Literature Cited ..................................................................................................................92
Introduction to the literature on the freshwater bivalves of North Carolina..................................................................................................................98
Websites for freshwater mollusks of North America ......................................................101
LIST OF FIGURES
Figure 1. Morphology of a Unionid shell and landmarks....................................................1 Figure 2. Internal shell landmarks of Corbiculidae and Sphaeriidae...................................2 Figure 3. Shell shape and beak sculpture.............................................................................3 Color Plates 1-10
LIST OF TABLES
Table 1. List of native freshwater unionid bivalves of North Carolina .............................11
Table 2. Distribution of Unionidae in North Carolina’s Atlantic Slope River basins............................................................................................................13
Table 3. Distribution of Unionidae in North Carolina’s Interior Basin river drainages........................................................................................................15
Table 4. Status list of North Carolina freshwater bivalves ................................................16
Table 5. A working list of the relationships of North Carolina Elliptio ............................17Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina iii
Page left blank on purpose.Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina 1
Figure 1. Morphology of a freshwater unionid shell, illustrating structures and terminology. a. exterior of right valve; b. interior of left valve (Reproduced from Burch 1975:5, fig. 2). Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina 2
Figure 2. Internal shell features of left (a) and right (b) valves of Corbicula fluminea and of left (c) and right (d) valves of Pisidium variabile, representing the Sphaeriidae. C2, C3, C4 are the cardinal teeth; AI, AII, AIII are the anterior lateral teeth; PI, PII, PIII are the posterior lateral teeth. Reprinted from Mackie (2001) with the author’s permission. Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina 3
Figure 3. Illustrations of shell shape and beak sculpture. Shell shape descriptions: (A) rhomboidal; (B) triangular or trigonal; (C) round; (D) quadrate; (E and F) oval or ovoid; and (G) elliptical. Posterior shell-ridge morphology: (H) posterior ridge convex; and (I) posterior ridge concave. Concentric ridge structures of umbos: (J) single-looped concentric ridges; (K) double-looped concentric ridges; (L) coarse concentric ridges; and (M) fine concentric ridges. (Reproduced from McMahon and Bogan 2001). Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina 4
Key to the freshwater bivalves of North Carolina
1 a. shell with a very sharp posterior ridge, shaped like a marine mussel, Mytilus, generally less than 30 millimeters, and attached to a hard substrate with byssal threads (pl. 10, fig. 58)[Not known from NC at this time].........Dreissena polymorpha
b. animal without byssal threads attaching adult animal to substrate, with or without teeth but not with above shape...........................................................................2
2 (1b) a. valves with cardinal teeth and two sets of lateral teeth (pl. 10, fig. 56, 57)....................3
b. valves with one set of lateral teeth and pseudocardinal teeth or without teeth (Unionidae) .............................................................................................................4
3 (2a) a. valves with serrated lateral teeth (Fig. 2; pl. 10, fig. 56, 57) ............Corbicula fluminea
b. valves with smooth lateral teeth (Fig. 2) [See Burch 1975b]...................... Sphaeriidae 4 (2b) a. origin of shell is from rivers or lakes draining into the Atlantic Ocean ...................... 5
b. origin of shell is from rivers or lakes draining into the Mississippi River Basin......................................................................................................................... 31
ATLANTIC COAST
5 (4a) a. shell with hinge teeth absent or greatly reduced.......................................................... 6
b. shell with pseudocardinal teeth present, with or without lateral teeth ...................... 11 6 (5a) a. umbo not projecting above the hinge-line ................................................................... 7
b. umbo projecting above the hinge-line ......................................................................... 8
7 (6a) a. ventral margin slightly concave to straight (pl. 8, fig. 48) ................................................................................................. Utterbackia imbecillis
b. ventral margin rounded (pl. 2, fig. 7) ........................................ Anodonta couperiana 8 (6b) a. beak sculpture double looped, shell uniformly thin..................................................... 9
b. beak sculpture consists of concentric bars................................................................. 10
9(8a) a. beak sculpture ridges all of the same height, common (pl.7, fig. 40) ........................... ................................................................................................... Pyganodon cataracta
b. beak sculpture ridges with pronounced bump or raised area in the bottom of the loop, introduced (pl. 7, fig. 41)............................................... Pyganodon grandis Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina 5
10 (8b) a. nacre usually orange in the beak cavity, pseudocardinal tooth area represented by a thickening near the umbo, ventral shell margin uniform thickness (pl. 8, fig. 43)............................................................................ Strophitus undulatus
b. Nacre bluish or white, hinge plate uniformly thin, teeth or swellings absent, ventral margin with a prominent thickened area along the anterior ventral margin below the pallial line (pl. 2, fig. 8)...................................Anodonta implicata
11 (5b) a. shell with lateral teeth absent or reduced, neither functional nor interlocking ......... 12
b. shell truncated, with well developed lateral teeth ..................................................... 14
12 (11a) a. shell elongate to elongate oval, inflated thin shell .................................................... 13
b. shell outline triangular, inflated but thin to thick shell, beak sculpture consists of large bars extending down onto the disk of the shell (pl. 1, fig. 4) ................................................................................................. Alasmidonta undulata
13 (12a) a. shell elongate, kidney shaped, periostracum greenish to brownish with obscured rays in adults (pl. 1, fig. 5) ........................................ Alasmidonta varicosa
b. shell elongate oval, periostracum yellowish background with wavy green rays, Long Creek Catawba River basin, known only from the type lot, extinct (pl. 1, fig. 3)................................................................................Alasmidonta robusta
14 (11b)a. right valve with two lateral teeth, small, rare (pl. 1, fig. 1).....Alasmidonta heterodon
b. right valve with one lateral tooth............................................................................... 15
15 (14b) a. shell with spines on the umbo and down on to the disc of the shell, but may be lost in adults, oval in outline and typically a yellowish brown periostracum............................................................................................................. 16
b. shell lacks any evidence of spines............................................................................. 17
16 (15a) a. shell from the Tar River basin (pl. 4, fig. 19) ............................ Elliptio steinstansana
b. shell from the Dan River drainage in the Roanoke River basin (pl. 7, fig. 37) .....................................................................................................Pleurobema collina
17 (15b)a. hinge plate in left valve with an additional small interdental or accessory tooth, giving the appearance of three pseudocardinal teeth, shell more or less compressed, shell shape rhomboid, periostracum dark green with numerous green rays, beak sculpture consists of prominent bars ............................................. 18
b. left valve without extra interdental tooth in left valve .............................................. 19 Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina 6
18 (17a) a. shell thick and maximum size114 mm, maximum height 68 mm, restricted to the Pee Dee and Wateree-Santee River drainages (pl. 5, fig. 29) .................................................................................................... Lasmigona decorata
b. shell relatively think, maximum size 62 mm, maximum height 33 mm, known
from the Pamlico, Neuse, and Cape Fear River systems (pl. 6, fig. 31) ..................................................................................................Lasmigona subviridis
19 (17b)a. shell shape rectangular to broadly triangular shell, beak cavity shallow, species is from an area extending from the Roanoke River Basin south to the headwaters of the Savannah River Basin (pl. 4, fig. 23)...............Fusconaia masoni
b. shell shape oval, round or rhomboid......................................................................... 20
20 (19b)a. shell shape rhomboid, or rectangular......................................................................... 21
b. shell shape oval or round........................................................................................... 24
21 (20a) a. shell usually more than twice as long as high........................................................... 22
b. shell usually less than twice as long as high............................................................. 28
22 (21a)a. nacre color white, shell inflated................................................................................. 23
b. nacre color typically some shade of purple, but ranges from white to salmon to purple, Elliptio [this genus contains basically three shell shapes, narrow and elongate: the Elliptio lanceolata complex; rectangular to elongate rectangular, with various degrees of inflation: the Elliptio complanata complex; those shells with short shell length, not too tall and inflated: the Elliptio icterina complex] [See Table 5 for species groups and figures for each species of Elliptio].
23 (22a) a. periostracum unrayed, shell thick, posterior end angled, periostracum mat or fuzzy, rectangular in shell shape (pl. 8, fig. 47) .....................Uniomerus caroliniana
b. periostracum rayed in juveniles, posterior end tapered to a point in middle of posterior margin, periostracum not mat (pl. 6, fig. 34) ...................... Ligumia nasuta
24 (20b)a. adult shell typically <40 mm in length, with a fuzzy or mat textured dark brown to black periostracum (pl. 8, fig. 45)....................................Toxolasma pullus
b. adult shell >40 mm in length, lacking the pronounced fuzzy periostracum.............. 25
25 (24b)a. shell shape oval to elongate oval, periostracum very shiny to mat with rays............ 26
b. shell shape oval, periostracum dull yellow, without rays or with fine rays all over the shell, found in or near tidewater, nacre often a salmon color (pl. 6, fig. 32.............................................................................................Leptodea ochracea Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina 7
26 (25a) a. periostracum shiny yellow, with fine green rays when present restricted to the posterior slope (pl. 5, fig. 25) .......................................................... Lampsilis cariosa
b. periostracum mat to smooth but not shiny ................................................................ 27
27 (26b)a. posterior ridge very sharp, maximum shell length <60mm, restricted to the Lake Waccamaw drainage (pl. 5, fig. 27) ....................................Lampsilis fullerkati
b. posterior ridge rounded, maximum size ca. 100 mm, inflated, wide spread, (pl. 5, fig. 28)................................................................................... Lampsilis radiata
28 (21b)a. periostracum greenish yellow, numerous green rays, shell relatively thin, oval to elongate oval, blade-like pseudocardinal teeth .................................................... 29
b. periostracum dark to black, shell thick, no green rays, shell shape oval to round (pl. 9, fig. 49) ........................................................................ Villosa constricta
29 (28a) a. shell outline elliptical, numerous broad green rays, bluish white to pink or purple nacre (pl. 10, fig. 55) ....................................................................Villosa vibex
b. shell outline elongate oval, rays not broad, nacre bluish white or iridescent............ 30
30 (29b)a. entire surface covered with narrow to very narrow green rays interrupted by growth lines (pl. 9, fig. 50)................................................................Villosa delumbis
b. numerous continuous dark green rays over most of the shell (pl. 9, fig. 54) ....................................................................................................Villosa vaughaniana
MISSISSIPPI RIVER BASIN
31 (4b) a. lacking lateral teeth or all evidence of any hinge teeth ............................................. 32
b. shell with both pseudocardinal and lateral teeth present ........................................... 38 32 (31a)a. shell with pseudocardinal teeth but lacking lateral teeth........................................... 33
b. shell with greatly reduced or totally lacking both pseudocardinal and lateral teeth.......................................................................................................................... 36
33 (32a) a. shell <25 mm, typically periostracum eroded off with periostracum restricted to narrow strip on shell margin, beak sculpture heavy bars extending down on the disc of the shell, upper Little Tennessee River basin (pl. 6, fig. 36) ...............................................................................................................Pegias fabula
b. periostracum not eroded as above ............................................................................. 34 Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina 8
34 (33b) a. hinge plate in left valve with an additional small interdental tooth giving the appearance of a third pseudocardinal tooth, beak sculpture consists of six double looped concentric ridges shell smooth (pl. 5, fig. 30) ................................................................................................... Lasmigona holstonia
b. hinge plate in left valve without an additional small interdental tooth ..................... 35
35 (34b)a. shell thin, inflated, shell shape elongate, posterior ridge rounded, periostracum shiny, some rays apparent even in adults (pl. 1, fig. 2) .............................................................................................Alasmidonta raveneliana
b. shell thickened anteriorly, shell shape ovate, rectangular to triangular, posterior ridge often angular, somewhat inflated, periostracum slightly glossy, with narrow and wide green rays (pl. 1, fig. 6)................ Alasmidonta viridis
36 (32b) a. shell with pseudocardinal tooth consisting of a slight swelling or knob, lateral tooth consisting of a rounded ridge, beak cavity copper colored, umbo centrally located (pl. 8, fig. 43) ................................................ Strophitus undulatus
b. hinge teeth completely absent ................................................................................... 37
37 (36b)a. umbo elevated well above the hinge line, shell shape variable, ranging from oval, elliptical to rhomboid, beak sculpture consists of double looped ridges with projections on the bottom of the loop (pl. 7, fig. 41) .......... Pyganodon grandis
b. umbo level with hinge line or below the level of the hinge line, shell shape elongate, inflated, dorsal and ventral margins nearly straight and parallel, beak sculpture consists of 5-6 fine irregular concentric ridges (pl. 8, fig. 48) .................................................................................................. Utterbackia imbecillis
38 (31b)a. shell with sculpture on the external shell surface...................................................... 39
b. shell with no plications, undulations, ridges, pustules or nodules............................. 42
39 (38a) a. shell with prominent pustules or nodules and/or undulations, plications or ridges........................................................................................................................ 40
b. shell with only prominent, well-defined pustules, knobs or nodules distributed across the shell.......................................................................................................... 41 Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina 9
40 (39a) a. shell with undulations, ridges, or plications on the posterior slope, no pustules or nodules on the surface, shell elongate, with a rounded posterior ridge, inflated with a blue to blue-green nacre color (pl. 6, fig. 35) ............................................................................................... Medionidus conradicus
b. shell with undulations, ridges or plications on the posterior slope and pustules on the disc or umbonal area, shell oval, elongate with a well-developed diagonal posterior ridge, nacre color white (pl. 8, fig. 46)........ Tritogonia verrucosa
41 (39b)a. pustules of uniform size, no broad green ray on umbo, periostracum of a uniform brownish, purple nacre, beak cavity deep and compressed (pl. 2, fig. 9)............................................................................................ Cyclonaias tuberculata
b. pustules generally large, often variable in size and shape, disc of the shell usually with a broad green stripe running down the disc of the shell with a variable number of pustules, varies from a very few to covering most of the shell, nacre color mostly white, beak cavity deep and open not compressed (pl. 7, fig. 42)............................................................................... Quadrula pustulosa
42 (38b) a. shell shape round ....................................................................................................... 43
b. shell shape not round................................................................................................. 46
43 (42a) a. umbo central or nearly central in the dorsal margin .................................................. 44
b. umbo anterior of the center of the shell..................................................................... 45
44 (43a) a. broad green ray extending from the umbo down only a short distance onto the disc of the shell, without pustules (pl. 7, fig. 42) ........................ Quadrula pustulosa
b. no broad green ray, shell with broad shallow to pronounced sulcus, fine green rays, shallow beak cavity, well developed hinge teeth, female shells with a swollen, extended or expanded portion of the posterior slope and posterior ventral margin of the shell (pl. 4, fig. 21)...........................Epioblasma capsaeformis
45 (43b)a. beak cavity deep compressed (pl. 4, fig. 24) ............................Fusconaia subrotunda
b. beak cavity shallow and open, shell with green rays at least on the umbo area with a thick shell, heavy lateral teeth, very shallow sulcus or missing, shallow to no beak cavity (pl. 6, fig. 33)............................Lexingtonia dolabelloides
46 (42b)a. shell shape not oval.................................................................................................... 48
b. shell shape oval to oblong ......................................................................................... 47 Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina 10
47 (46b)a. shell shape oval, inflated, rayed, thin to thick shell, posterior ridge rounded or sharp, nacre variously white to pink or salmon (pl. 5, fig. 26) ....................................................................................................... Lampsilis fasciola
b. shell shape oblong to elongate oval, male shells are oval while female shells have a truncate posterior margin, purple nacre ranges from deep purple to copper (pl. 9, fig. 53)................................................................ Villosa vanuxemensis
48 (46a) a. shell shape rectangular, triangular, or square with sulcus ......................................... 49
b. shell shape elongate, 2 to 4 times longer than high................................................... 50
49 (48a) a. shell shape rectangular, with green rays on the umbo (pl. 4, fig. 22) ................................................................................................. Fusconaia barnesiana
b. shell shape triangular to broadly triangular (pl. 7, fig. 38)........ Pleurobema oviforme
50 (48b)a. thin shelled, shell inflated, periostracum usually rayed, adult shell length >50 mm, shell hinge thin, usually heavily rayed (pl. 9, fig. 51)......... Villosa iris complex
b. thick shelled............................................................................................................... 51 51 (50b)a. shell compressed........................................................................................................ 52
b. shell inflated .............................................................................................................. 53
52 (51a) a. shell hinge massive, curved, nacre white, periostracum with interrupted green rays (pl. 7, fig. 39) ........................................................... Ptychobranchus fasciolaris
b. hinge lighter, straight, nacre purple to white, periostracum typically unrayed (pl. 3, fig. 13)...................................................................................... Elliptio dilatata
53 (51b)a. periostracum smooth, color olive green with numerous rays, nacre white (pl. 9, fig. 52) ............................................................................................. Villosa trabalis
b. periostracum mat, color ranges from greenish to black without rays, nacre purple (pl. 8, fig. 44)....................................................................... Toxolasma lividus Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina 11
Table 1.List of Native Freshwater Unionid Bivalves of North Carolina
Alasmidonta heterodon (Lea, 1829) Dwarf Wedgemussel Alasmidonta raveneliana (Lea, 1834) Appalachian Elktoe [Interior Basin] Alasmidonta robusta Clarke, 1981Carolina Elktoe Alasmidonta undulata (Say, 1817) Triangular Floater Alasmidonta varicosa (Lamarck, 1819) Brook floater Alasmidonta viridis (Rafinesque, 1820) Slippershell Mussel [Interior Basin] Anodonta couperiana Lea, 1840 Barrel Floater Anodonta implicata Say, 1829 Alewife Floater Cyclonaias tuberculata (Rafinesque, 1820) Purple Wartyback [Interior Basin] Elliptio cistellaeformis (Lea, 1863) Box Spike Elliptio complanata (Lightfoot, 1786) Eastern Elliptio Elliptio congaraea (Lea, 1831) Carolina Slabshell Elliptio dilatata (Rafinesque, 1820) Spike [Interior Basin] Elliptio folliculata (Lea, 1838) Pod Lance Elliptio icterina (Conrad, 1834) Variable Spike Elliptio judithae Clarke, 1981 Plicate Spike Elliptio lanceolata (Lea, 1828) Yellow Lance Elliptio marsupiobesa Fuller, 1972 Cape Fear Spike Elliptio roanokensis (Lea, 1838) Roanoke Slabshell Elliptio steinstansana Johnson and Clarke, 1983 Tar River Spinymussel Elliptio waccamawensis Lea, 1863 Waccamaw Spike Epioblasma capsaeformis (Lea, 1834) Oyster Mussel [Interior Basin] Fusconaia barnesiana (Lea, 1838) Tennessee Pigtoe [Interior Basin] Fusconaia masoni (Conrad, 1834) Atlantic Pigtoe Fusconaia subrotunda (Lea, 1831) Longsolid [Interior Basin] Lampsilis cariosa (Say, 1817) Yellow Lampmussel Lampsilis fasciola Rafinesque, 1820 Wavyrayed Lampmussel [Interior Basin] Lampsilis fullerkati Johnson, 1984 Waccamaw Fatmucket Lampsilis radiata radiata (Gmelin, 1791) Eastern Lampmussel Lampsilis radiata conspicua (Lea, 1872) Carolina Fatmucket Lasmigona decorata (Lea, 1852) Carolina Heelsplitter Lasmigona holstonia (Lea, 1838) Tennessee Heelsplitter [Interior Basin] Lasmigona subviridus (Conrad, 1835) Green Floater [Atlantic/Interior Basin] Leptodea ochracea (Say, 1817) Tidewater Mucket Lexingtonia dolabelloides (Lea, 1840) Slabside Pearlymussel [Interior Basin] Ligumia nasuta (Say, 1817) Eastern Pondmussel Medionidus conradicus (Lea, 1831) Cumberland Moccasinshell Pegias fabula (Lea, 1838) Littlewing Pearlymussel [Interior Basin] Pleurobema collina (Conrad, 1836) James Spinymussel Pleurobema oviforme (Conrad, 1834) Tennessee Clubshell [Interior Basin] Ptychobranchus fasciolaris (Rafinesque, 1820) Kidneyshell [Interior Basin] Pyganodon cataracta (Say, 1817) Eastern Floater Pyganodon grandis (Say, 1829) Giant Floater [Interior Basin] Quadrula pustulosa (Lea, 1831) Pimpleback [Interior Basin] Strophitus undulatus (Say, 1817) Creeper [Atlantic/Interior Basin] Toxolasma lividus Rafinesque, 1831 Purple Lilliput [Interior Basin] Toxolasma pullus (Conrad, 1838) Savannah Lilliput Tritogonia verrucosa (Rafinesque, 1820) Pistolgrip [Interior Basin] Uniomerus carolinianus (Bosc, 1801) Florida PondhornBogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina 12
Utterbackia imbecillis (Say, 1829) Paper Pondshell [Atlantic/Interior Basin] Villosa constricta (Conrad, 1838) Notched Rainbow Villosa delumbis (Conrad, 1834) Eastern Creekshell Villosa iris (Lea, 1830) Rainbow [Interior Basin] Villosa trabalis (Conrad, 1834) Cumberland Bean [Interior Basin] Villosa vanuxemensis (Lea, 1838) Mountain Creekshell [Interior Basin] Villosa vaughaniana (Lea, 1838) Carolina Creekshell Villosa vibex (Conrad, 1834) Southern RainbowTable 2. Distribution of Unionidae in North Carolina’s Atlantic Slope River Basins Within River Basin: X= Extant, H= Historic, S= in S. Carolina, ScH=SC historic, V= in Virginia
Species
Savannah
Broad
Catawba
Pee-Dee
Lumber
Waccamaw
Cape Fear
White Oak
Neuse
Pamlico
Roanoke
Chowan
Pasquotank
Anodonta implicata
X
X
X
Anodonta couperiana
S
H
Pyganodon cataracta
S
X
X
X
X
X
X
X
X
X
Utterbackia imbecillis
X
S
X
X
X
X
X
X
X
Strophitus undulatus
X
S
X
X
X
X
X
V
Alasmidonta varicosa
S
X
X
X
X
X
Alasmidonta heterodon
X
X
Alasmidonta undulata
S
X
X
X
X
X
X
Lasmigona decorata
S
X
X
Lasmigona subviridis
H
X
X
X
Fusconaia masoni
ScH
H
X
X
X
X
X1
V
Pleurobema collina
X
Elliptio complanata
S
X
X
X
X
X
X
X
X
X
X
X
Elliptio cistellaeformis
X
X
X
X
X
X
Elliptio mediocris
X
X
X
Elliptio marsupiobesa
S
X
X
X
Elliptio congaraea
S
X
X
X
X
V
Elliptio waccamawensis
X
Elliptio raveneli
X
X
X
X
X
X
V
Elliptio icterina
S
X
X
X
X
X
X
X
X
X
X
V
Elliptio lanceolata
X
X
V
Elliptio angustata
X
X
X
X
X
X
V
Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina
13Species
Savannah
Broad
Catawba
Pee-Dee
Lumber
Waccamaw
Cape Fear
White Oak
Neuse
Pamlico
Roanoke
Chowan
Pasquotank
Elliptio producta
S
S
X
X
X
Elliptio folliculate
S
S
X
X
X
Elliptio shepardiana
X
X
Elliptio viridula
X
X
X
X
X
Elliptio emmonsii
Elliptio roanokensis
S
X
X
X
X
X
Elliptio steinstansana
X
X
X
Uniomerus sp.
S
S
X
X
X
X
X
X
Leptodea ochracea
ScH
X
H
X
Toxolasma pullus
S
X
H
X
H
X
Ligumia nasuta
S
X
X
H
V
Villosa vibex
S
X
X
X
Villosa delumbis
S
X
X
X
X
Villosa constricta
X
X
X
X
X
X
Villosa vaughaniana
X
X
X
X
V
Lampsilis radiata radiate
X
X
X
X
X
Lampsilis radiata conspicua
X
X
Lampsilis fullerkati
X
Lampsilis splendida
S
X
X
Lampsilis cariosa
S
X
X
X
X
V
Lampsilis n.s.
X
X
X
Total taxa for River Basin
20
7
16
27
8
17
29
3
24
24
17
19
2
Prepared by J.M. Alderman, J.A. Johnson, and Brian T. Watson, January 31, 20021T. Savidge (Per. Comm. March 2002) Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina
Table 3 Distribution of Extant Unionidae in North Carolina’s Interior Basin
Within River Basin: X =Extant, H= Recently Extirpated, I=Introduced Species
Hiwassee
Little Tennessee
Pigeon
French Broad
Watauga
New
Pyganodon grandis
X
Strophitus undulatus
X
Lasmgona holstonia
H
X1
X2
Lasmigona subviridis
X
X
Elliptio dilatata
X
X
H
X
Elliptio complanata (Introduced)
I
Alasmidonta raveneliana
X
X
X
Alasmidonta viridis
X
X
Cyclonaias tuberculata
X
Tritigonia verrucosa
H
Pleurobema oviforme
X
X
X
Fusconaia barnesiana
X
X
Fusconaia subrotunda
X
X
Pegias fabula
X
X
Villosa iris
X
X
H
Villosa vanuxemensis
X
Lampsilis fasciola
X
X
H
X
Medionidus conradicus
H
Epioblasma capsaeformis
H
Ptychobranchus fasciolaris
H
Toxolasma lividus
H
Lexingtonia dolabelloides
?
Villosa trabalis
?
Prepared By J. M. Alderman, Judith A. Johnson, and Brian T. Watson, February 4, 2002 1W. McLaren (Pers. Comm., 1 July 2002). 2T. Savidge (Pers. Comm. March 2002).Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina
Table 4. Status List of North Carolina freshwater bivalves
FEDERAL AND STATE ENDANGERED
Alasmidonta heterodon Alasmidonta raveneliana Elliptio steinstansana Epioblasma capsaeformis Lasmigona decorata Pegias fabula Pleurobema collina Villosa trabalis
STATE ENDANGERED Alasmidonta varicosa (effective July 1, 2002)
Alasmidonta viridis Anodonta couperiana Elliptio lanceolata (effective July 1, 2002) Elliptio waccamawensis (effective July 1, 2002)
Fusconaia barnesiana Fusconaia masoni (effective July 1, 2002) Lampsilis cariosa (effective July 1, 2002) Lasmigona holstonia Lasmigona subviridis Toxolasma pullus (effective July 1, 2002) Villosa vaughaniana (effective July 1, 2002)
STATE THREATENED
Alasmidonta undulata Anodonta implicata (effective July 1, 2002) Elliptio roanokensis Lampsilis fullerkati Lampsilis radiata conspicua (effective July 1, 2002) Lampsilis radiata radiata (effective July 1, 2002) Leptocea ochracea (effective July 1, 2002) Ligumia nasuta (effective July 1, 2002) Strophitus undulatus Villosa vanuxemensis
STATE SPECIAL CONCERN
Elliptio dilatata Elliptio folliculata Elliptio marsupiobesa Lampsilis fasciola Villosa constricta Villosa iris
SIGNIFICANTLY RARE (Natural Heritage Program)
Cyclonaias tuberculata Villosa delumbis
STATE EXTIRPATED
Epioblasma capsaeformis Medionidus conradicus Ptychobranchus fasciolaris Quadrula pustulosa Toxolasma lividus Tritogonia verrucosa Villosa trabalis
EXTINCT
Alasmidonta robusta Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina
Table 5. A working list of the Elliptio of North Carolina. A preliminary idea of the relationships of North Carolina Elliptio
ELLIPTIO COMPLANATA GROUP Elliptio complanata (Lightfoot, 1786) Eastern Elliptio [pl. 2, fig. 11] Elliptio congaraea (Lea, 1831) Carolina Slabshell [pl. 2, fig. 12] Elliptio judithae Clarke, 1981 Plicate Spike [p. 38] Elliptio roanokensis (Lea, 1838) Roanoke Slabshell [pl. 3, fig. 18] Elliptio steinstansana Johnson and Clarke, 1983 Tar River Spinymussel [pl.4,
fig. 19] Elliptio waccamawensis (Lea, 1863) Waccamaw Spike [pl.4, fig. 20] Elliptio raveneli (Conrad, 1834) Carolina Spike*
ELLIPTIO ICTERINA GROUP Elliptio cistellaeformis (Lea, 1863) Box Spike [pl. 2, fig. 10] Elliptio icterina (Conrad, 1834) Variable Spike [pl. 3, fig. 15] Elliptio marsupiobesa Fuller, 1972 Cape Fear Spike [pl.3, fig. 17]
ELLIPTIO LANCEOLATA GROUP Elliptio folliculata (Lea, 1838) Pod Lance [pl. 3, fig. 14] Elliptio lanceolata (Lea, 1828) Yellow Lance [pl. 3, fig. 16] Elliptio angustata (Lea, 1831) Carolina Lance* Elliptio fisheriana (Lea, 1838) Northern Lance* Elliptio viridulus (Lea, 1863)* Elliptio emmonsii (Lea, 1857)* Elliptio nasutilus (Lea, 1863)*
ELLIPTIO DILATATA GROUP Elliptio dilatata (Rafinesque, 1820) Spike [Interior Basin] [pl. 3, fig. 13]
*These taxa are not treated here but, you will encounter in the literature on Elliptio from North Carolina.Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina
CORBICULIDAE Corbicula fluminea (Müller, 1776) INTRODUCED Asian Clam
Plate 10, Figure 56, 57 General Distribution: The Asian Clam appears to have been introduced into North America sometime during or before the 1920s (Counts, 1986). It was first collected in the United States along the banks of the Columbia River in Pacific County, Washington, in 1938 (Burch, 1944), and since then it has invaded nearly every major river system in the country. North Carolina Distribution: This introduced species is widespread in all rivers, most reservoirs and many lakes. Description: The shell is fairly small, seldom exceeding 50 mm in length, very solid, ovate when young, and triangular in outline when mature. Beaks are high, full, directed inward, and elevated well above the hinge line, and centrally located. Thin, prominent concentric rings indicate growth periods. There are three cardinal teeth directly below the beaks in each valve, with two straight to slightly curved lateral teeth on each side in the right valve and one on each side in the left valve. The lateral teeth are serrated, a character distinguishing Corbicula from the Sphaeriidae. The beak cavity is deep. The periostracum is a light yellowish olive to cream-colored in immature clams, changing with age to tan, olive, and, finally, dark brown to black in old individuals. Very young individuals possess a characteristic dark stripe or band on the anterior slope of the valves. The nacre is white to a shiny light purple, darkest along the lateral teeth and in the beak cavity. The entire inner surface of adults is a very light purple and white, appearing highly polished outside the pallial line.
Life History and Ecology: Unlike our native freshwater mussels, the juvenile or larva (called a veliger) of the Asian Clam is free swimming and does not require a host for partial development. Oesch (1984) noted that in Missouri the spawning time of Corbicula generally is between May and September. The period of growth of the free-swimming veliger lasts about 7–10 days (McMahon and Bogan, 2001 The Asian Clam reaches its greatest population densities in a substrate of almost pure sand or one of mixed sand, silt, and mud. Although it thrives in rivers with slow to moderate current, typically at depths of less than three feet,
C. fluminea may become abundant and grow to a large size in the quiet waters of small ponds. This small clam is highly resistant to desiccation and can survive for weeks in damp sand or mud. Status: INTRODUCED Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina
UNIONIDAE
Alasmidonta heterodon
(Lea, 1829) Dwarf Wedgemussel
Plate 1, Figure 1
Synonymy: Unio heterodon Lea, 1829; Lea, 1829:428, pl. 8, fig. 11
Type Locality: Schuylkill [River] and
Derby [sic] Creek [mostly in Delaware
County] P[ennsylvani]a
General Distribution: Clarke (1981:32,
34, Fig. 10) listed the distribution for the
Dwarf Wedgemussel as occurring from
the Neuse River basin, North Carolina,
in the south, north to the Petitcodiac
River Basin, New Brunswick, Canada.
Distribution of A. heterodon is sporadic
in the river basins between these two
river basins.
North Carolina Distribution: This
species occurs in the Neuse and Pamlico
River basins in North Carolina (Clarke,
1981; Table 2).
Description: The shell is small,
somewhat inflated and rather thin,
thickened anteriorly, reaching a shell
length of about 56 mm. Anterior margin
sharply curved, ventral margin broadly
curved to straight, and the posterior
margin is roundly pointed near the base
and broadly truncated above. The shells
of males are more compressed and the
shell shape is more ovate and elongate
with a reduced posterior ridge, the
posterior slope is not truncated. Female
shells are more swollen around the
posterior ridge and have a more distinct
posterior ridge making the posterior
slope appear truncated, thus making the
whole shell appear more trapezoidal
(Ortmann 1919:174). Posterior ridge
well developed, extending to the
posterior ventral margin and coming to a
point. Beaks are low, rounded and
projecting slightly above the hinge line, with beak sculpture consisting of a few well developed ridges or bars, running parallel to the growth lines, subsequent beak sculpture is double looped. This sculpture is visible only on young specimens. Surface marked by uneven growth lines. Left valve has one or two compressed, pseudocardinal teeth, and may have one to three lamellar lateral teeth. Right valve with two compressed, pseudocardinal teeth and two lamellar lateral teeth that extend to the end of the ligament. This is the reverse of the rest of the species with lateral teeth. Interdentum marked by an accessory dentacle in the left valve and a corresponding depression in the right valve, beak cavity rather narrow and not very deep. Periostracum color varies from yellowish olive brown to green to black with some specimens with variable width, faint, reddish-brown rays. Nacre color is bluish white Life History and Ecology: Fuller (1977:168) characterized the habitat of the Dwarf Wedgemussel as: “stable stream floors of sand and/or fine gravel, but like most other member of the subfamily Anodontinae, it has a considerable tolerance of sediment overlying formerly clean streambeds.” Ortmann (1919) found this species gravid in February to April in Pennsylvania. Clarke (1981b:31-32, fig.
9) described the glochidium of the Dwarf Wedgemussel as depressed, pyriform with a straight hinge, with a ventral hook, glochidial length 0.325mm and height 0.255 mm. Hoggarth (1999:36, 39, figs. 19a-f) commented that glochidium was asymmetrical in outline and listed the length as 330-338 μm and height as 258-268 μm. Michaelson and Neves (1995) listed three fish species, which serve as hosts Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina
for the glochidia of the Dwarf Wedgemussel in laboratory studies: Tessellated Darter (Etheostoma olmstedi), Johnny Darter (E. nigrum) and the Mottled Sculpin (Cottus bairdi). Wicklow (1999) reported the Atlantic Salmon (Salmo salar) as a suitable host for the glochidia of this species. Status: Endangered (Williams et al., 1993:10). This species is federally and state listed as endangered. Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina
Alasmidonta raveneliana
(Lea, 1834) Appalachian Elktoe
Plate 1, Figure 2
Synonymy: Margaritana raveneliana Lea, 1834; Lea, 1834:106,
pl. 17, fig. 50 Type Locality: French Broad and Swananoe [sic] rivers, North Carolina. General Distribution: The Appalachian Elktoe is restricted to the tributaries of the Tennessee River in East Tennessee and western North Carolina. North Carolina Distribution: This species is found in the Nolichucky River, Little Tennesee River basin and the French Broad River in western North Carolina (Clarke, 1981b, T. Savidge, Pers. Comm. March 2002) Description: The Appalachian Elktoe is oblong, somewhat kidney-shaped in outline, moderately inflated, and thin-shelled but not fragile. The anterior margin is sharply rounded, and the posterior margin is broadly rounded, coming to a rounded point close to the posterior ventral margin. The ventral margin is nearly straight or slightly concave, and the dorsal margin is nearly straight posterior to the beaks. The posterior ridge is rounded and often double; the posterior slope is slightly concave, but not as acute as in the Elktoe (Alasmidonta marginata). The beaks are moderately full, rounded, and situated on the anterior third of the shell and slightly above the hinge line. Beak sculpture consists of a few fairly heavy straight or slightly double looped bars, which terminate at the posterior ridge. The Appalachian Elktoe reaches a maximum length of about 80 mm (Clarke, 1981b). Specimens > 120 mm have been seen in the Pigion and Little Rivers (T. Savidge, Pers. Comm. March 2002).
The left valve has a single small, compressed, pyramidal pseudocardinal tooth; the lateral tooth is reduced to a swelling or ridge and is not an articulating tooth. The left valve also has a moderate-sized interdental projection. The right valve has a single small compressed pyramidal pseudocardinal tooth and a single reduced ridge along the hinge line in place of the lateral tooth. Beak cavity is quite shallow. Adductor muscle scars are shallow, becoming somewhat deeper and more distinct in large mature individuals. Dorsal muscle scars are present and consist of one or two short grooves. The pallial line is absent in some individuals, complete and distinct in others. The periostracum varies from yellowish brown in younger specimens to dark brown or black in adults with faint, often interrupted green rays. The surface is mostly smooth, but interrupted by concentric growth lines. There may be some fine plications on the posterior slope on juvenile specimens. Nacre color varies from a uniform bluish white to greenish, sometimes with a purplish tint, to salmon or pinkish in the center of the shell and beak cavity. (Parmalee and Bogan, 1998). Life History and Ecology: Alasmidonta raveneliana may be locally common in some rivers, such as the Little Tennessee and Nolichucky in North Carolina, where it inhabits a sand and gravel substrate among cobbles and boulders and under flat rocks, usually in moderate current at depths of less than three feet. Ortmann (1921) reported that the breeding season ended in May, the species being bradytictic. Watters (1994) lists the fish host for the glochidia of Alasmidonta raveneliana as the Banded Sculpin (Cottus carolinae). Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina
Status: Endangered (Williams et al., 1993:10). The U.S. Fish and Wildlife Service has developed a recovery plan for this species (U.S. Fish and Wildlife Service, 1996). This species federally and state listed as endangered. The U.S. Fish and Wildlife Service (2001) has proposed critical habitat for the Appalachian Elktoe. Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina
Alasmidonta robusta Clarke, 1981 Carolina Elktoe
Plate 1, Figure 3
Synonymy: Alasmidonta robusta Clarke, 1981: Clarke, 1981b:81-84, figs. 23, 27
Type Locality: Long Creek, a tributary of the Catawba River, Mecklenburg County, North Carolina. General Distribution: Long Creek, tributary of the Catawba River, Mecklenburg County, North Carolina (Clarke, 1981b). North Carolina Distribution: Long Creek, tributary of the Catawba River, Mecklenburg County, North Carolina (Clarke, 1981b). Description: The Carolina Elktoe is known from five specimens. The length ranges from 42 to 66 mm; the height ranges from 26 to 42 mm; the width ranges from 18 to 33 mm. The holotype is 66 mm long, 43 mm high and 33.2 mm wide. The following abbreviated description is taken from Keferl and Shelly (1988). A more complete description can be obtained from Clarke (1981b). The shell of the Carolina Elktoe is thin and sturdy, the anterior margin is well rounded; the ventral margin broadly curved; the posterior end forms a round point below the center. The periostracum is glossy, pale greenish-yellow with broad greenish rays that diminish at the posterior ridge. The posterior slope is covered with corrugations that are perpendicular to the posterior margin of the posterior slope. The Carolina Elktoe has a large interdental projection in the left valve. See Keferl and Shelly (1988) for a comparison with Alasmidonta varicosa (Lamarck, 1819) (Adams et al., 1990). Life History: Nothing is known of the about the specific habitat of the Carolina
Elktoe. Long Creek, its only collection site, is a small creek with a fairly steep gradient and substrates that vary from mud to bedrock. The stream has numerous deep isolated pools separated by rapids over small rocks, boulders and bedrock. Host fish information on this species is unknown (Adams et al., 1990). Status: According to Keferl and Shelly (1988), Alasmidonta robusta was not found in any part of the Catawba or Pee Dee river systems (Adams 1990). A thorough search of its only known locality yielded no specimens. Based upon current data this species is probably extinct. Clarke (1981b). Williams et al. (1993:10) listed it as extinct. Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina
Alasmidonta undulata (Say, 1817) Triangle Floater
Plate 1, Figure 4
Synonymy: Monodonta undulata Say, 1817; Say, 1817: no pagination, pl. 3, fig. 3
Type Locality: Delaware and Schuylkill
rivers [near Philadelphia, Philadelphia
County, Pennsylvania]
General Distribution: extending from
the Bosquet River of the lower St.
Lawrence River Basin south to the
Catawba River of North Carolina.
North Carolina Distribution: This
species is found in the Chowan, Pamlico,
Roanoke, Neuse, Cape Fear, and Pee
Dee River basins (Clarke, 1981b; Table
2) Description: Shell shape is subtriangular to ovate, solid, thicker anteriorly than in the posterior, shell is subinflated to inflated with maximum inflation at the middle of the shell, maximum shell length about 75 mm. Anterior shell margin rounded, ventral margin broadly rounded, posterior margin roundly pointed below the midline. Sexual dimorphism is not apparent. Posterior ridge present and rounded but often indistinct, the posterior slope somewhat compressed. Beaks are more or less full inflated and somewhat elevated above the hinge line, beak sculpture is extremely heavy, strong ridges that run parallel with the growth lines and composed of five prominent, single-looped, curved ridges that extend out onto the shell surface (Clarke, 1981b). Posterior slope sometimes marked by oblique ridges or corrugations. Periostracum is smooth and shiny. Left valve with a single short, stumpy, sculptured pseudocardinal teeth. There is usually a well-developed interdental projection present. Right valve has two short stumpy often-sculptured pseudocardinal teeth. The interdental area is broad and flat, with the lateral teeth either short and vestigial or absent. The beak cavity is triangular, compressed and rather deep. Periostracum is yellowish, greenish, with broad, green or blackish rays of variable width in juvenile specimens, becoming black with age. Growth lines are rather indistinct. Nacre color is typically white anteriorly, but including salmon, pink or red, becoming iridescent posteriorly. Life History and Ecology: Ortmann (1919) lists the Triangle Floater as being gravid from July to September and April to June while Clarke (1981b) lists gravid females from 28 August to 24 October. Ortmann (1919) reported this species as common in smaller rivers and streams, going well into the headwaters, found mainly in quiet waters with some current, avoiding the riffles, living in coarser gravel and sand. It does not appear to like slack water but can be found in ponds and canals. Lellis (Pers. Comm. 1996) and the authors have observed this species deeply buried during the summer but sitting up on top of the substrate in January and February when water temperatures are at the coldest. Host fishes confirmed in the laboratory include the Blacknose Dace (Rhinichthys atratulus), Common Shiner (Luxilus cornutus), Fallfish (Semotilus corporalis), Largemouth Bass (Micropterus salmoides), Longnose Dace (Rhinichthys cataractae), Pumpkinseed (Lepomis gibbosus), Slimy Sculpin (Cottus cognatus), White Sucker (Catostomus commersoni), (Watters et al., 1999; from Nedeau et al., 2000:67). Status: Special Concern (Williams et al., 1993:10). This species is listed as State Threatened in North Carolina. Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina
Alasmidonta varicosa
(Lamarck, 1819) Brook Floater
Plate 1, Figure 5
Synonymy: Unio varicosa Lamarck, 1819; Lamarck, 1819:78
Type Locality: La rivière Schuylkill
[Schuylkill] près de Philadelphie
[Philadelphia Co. Pennsylvania] … aussi
dans le lac Champlain
General Distribution: Lower St
Lawrence River basin south in streams
and rivers draining into the Atlantic to
South Carolina (Clarke, 1981).
North Carolina Distribution: The
Brook Floater is found in Roanoke,
Neuse, Cape Fear, Pee Dee and Catawba
River basins in North Carolina (Clarke,
1981b; Table 2).
Description: Shell shape is oblong, long
rhomboid, thin-shelled, but slightly
thickened anteriorly, slightly inflated
with the maximum inflation at the
posterior ridge, maximum length is
about 70 mm. Anterior shell margin is
abruptly curved, the ventral margin is
long, and centrally gently concave, the
posterior margin roundly biangulate
below and obliquely flattened or flatly
curved above. Female shells may be
slightly more swollen in the area of the
posterior ridge, but in many cases the
sex cannot be determined based on shell
characters. Posterior ridge is broad,
rounded, and inflated. Posterior slope is
flattened and slightly concave and
covered with numerous, low
corrugations or ridges. Beaks are
narrow and bluntly pointed and located
about 1/3 the distance from the anterior
end and project only slightly above the
hinge line. Beak sculpture is coarse,
variable and composed of a few single-
looped or occasionally double-looped
ridges, mostly seen in juvenile
specimens. Growth ridges are marked by concentric ridges, the periostracum is generally smooth except on the posterior slope. Left valve with a single small rounded variously developed or reduced pseudocardinal tooth, some specimens also have an interdental projection or denticle, lateral teeth are vestigial or entirely absent. Right valve has a single small rounded or rudimentary pseudocardinal tooth. Beak cavity is open and shallow. Periostracum is yellowish but more often greenish and partly or completely covered with dark greenish rays in juveniles, becoming brownish with rays partially obscured to almost black in adult specimens. The periostracal color on the posterior slope is the same as the rest of the shell, not yellowish as in Alasmidonta marginata. Nacre color is whitish or bluish-white, often with salmon, pink or purple shades in the beak cavity (Ortmann, 1919; Clarke, 1981b). Life History and Ecology: Ortmann (1919:191-192) reported gravid females from 9 August to 8 September and 3 May with glochidial discharge in May. Ortmann (1919) reported this species evenly distributed across eastern Pennsylvania except in the larger rivers and more common in smaller rivers and streams. Ortmann (1919:104) described the ecology of the Brook Floater as “It prefers strong currents and gravelly bottoms, thus being most frequently found in and near riffles.” Lellis (Pers. Comm. 1996) has observed this species deeply buried during the summer but sitting up on top of the substrate in January and February when water temperatures are at the coldest. The Blacknose Dace (Rhinichthys atratulus), Golden Shiner (Notemigonus chrysoleucas), Longnose dace (Rhinichthys cataractae), Margined Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina
Madtom (Schilbeodes marginatus marginatus) Pumpkinseed (Lepomis gibbosus), Slimy Sculpin (Cottus cognatus), and the Yellow Perch (Perca flavescens) have been identified in the laboratory as potential hostfish for the glochidia of this species (Wicklow and Richardson, 1995; Nedeau et al., 2000). Status: Threatened (Williams et al., 1993:10). This species is listed as State Endangered in North Carolina, effective July 1, 2002. Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina
Alasmidonta viridis
(Rafinesque, 1820) Slippershell Mussel
Plate 1, Figure 6
Synonymy: Unio viridis Rafinesque, 1820; Rafinesque, 1820:293
Type Locality: Ohio River.
General Distribution: Upper
Mississippi River drainage; Ohio,
Cumberland, and Tennessee rivers;
lower and middle sections of the St.
Lawrence River systems: Lake Huron,
Lake St. Clair, and Lake Erie drainages
in Canada (Clarke, 1981a).
North Carolina Distribution: This
species is known from the Little
Tennessee , Mills and French Broad
Rivers (Table 3).
Description:: The shell is small,
rhomboid, moderately solid, and slightly
inflated. Maximum shell length of adult
specimens seldom exceeds 55 mm. The
anterior end is rounded; the posterior end
is squared or obliquely truncated. The
posterior ridge is high, rounded, and
usually ends as a blunt point at the base
of the shell. Beaks are moderately
swollen, only slightly elevated; sculpture
consists of 5–6 irregular, heavy loops,
the first one or two are diagonal to the
hinge line, and the others are somewhat
concentric. The surface has uneven
growth lines, the rest periods appear as
raised, dark-lined ridges. The
pseudocardinal teeth in both valves are
somewhat rudimentary, or they appear as
elevated, triangular projections, usually
doubled in the left valve. Lateral teeth
are indistinct, being represented as a
slight swelling of the hinge line. The
beak cavity is relatively shallow; the
interdentum is narrow or absent. The
periostracum in young shells is a dull
eggshell white, greenish or yellowish,
with numerous wavy green rays; the
colors are darker and the rays less distinct in old shells. The nacre is a dull white, and the posterior margin is slightly iridescent. (Parmalee and Bogan, 1998). Life History and Ecology: A species of small creeks and shallow streams today, A. viridis once inhabited the shoals and riffles of large rivers such as the French Broad and Holston before impoundment. The Slippershell Mussel may typically be found living in a substrate composed of sand and fine gravel, although in stretches where there is a continuous current this small naiad will thrive in a mud and sand bottom among the roots of aquatic vegetation. Host fish for the glochidia include the Banded Sculpin (Cottus carolinae) and probably the Mottled Sculpin (C. bairdi) and Johnny Darter (Etheostoma nigrum) (Zale and Neves, 1982c; Watters, 1994). Baker (1928:186) states that the species in Wisconsin is “[p]robably bradytictic, with mature glochidia in the fall (September).” Individuals of this species have been observed spawning in January and February in the upper Little Tennessee River, North Carolina (Ahlstedt, pers. comm., 1994). Females lay on the substrate surface while spawning. Status: Special Concern (Williams et al., 1993:10). This species is considered State Endangered in North Carolina, effective July 1, 2002. Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina
Anodonta couperiana Lea, 1840 Barrel Floater
Plate 2, Figure 7
Synonymy: Anodonta couperiana Lea, 1840; Lea, 1840:227,
pl. 20, fig, 146 Type Locality:
McIntosh County, Georgia General Distribution: The barrel floater is found from Florida's Apalachicola region to the Cape Fear drainage basin in North Carolina. North Carolina Distribution: This species has been extirpated from one of its two known locations in North Carolina. The barrel floater was once known from the Greenfield Lake basin near Wilmington and the lower Cape Fear River (Adams et al., 1990). Vidrine (1980) documents this species from Bladen County (Adams et al., 1990). However, there are no recent records of the Barrel Floater in North Carolina (J. Alderman, Pers. Comm. July 2002). Description: The barrel floater may reach over 100 mm in length. Like other Anodonta, this species also lacks pseudocardinal and lateral teeth. The shell of the barrel floater is similar to that of Utterbackia imbecillis in that the umbos do not extend above the dorsal margin. However, the barrel floater's height to length ratio is around 2 compared with 1.5 for Utterbackia imbecillis. The ventral margin of the barrel floater is broadly rounded and there are fine green rays on the periostracum (Adams et al., 1990). Life History: According to Johnson (1970), the barrel floater is found in ponds and slow-flowing streams with mud or sand bottoms. The host fish for this species is unknown. Status: Williams et al. (1993:10) listed as special concern. This species is listed as State Endangered. Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina
Anodonta implicata Say, 1829 Alewife Floater
Plate 2, Figure 8
Synonymy: Anodonta implicata Say, 1829; Say, 1829:340
Type Locality: Pond in Danvers
[Essex Co.] Massachusetts. Changed by
Johnson (1946:112, pl. 16, figs. 1, 2)
when he selected a neotype to Agawam
River (outlet of Halfway Pond),
Plymouth [Plymouth Co.]
Massachusetts.
General Distribution: North Atlantic
Slope rivers from New Brunswick, Nova
Scotia, and Quebec, Canada south to the
Potomac River, Maryland, with a
disjunct population in the Chowan River,
North Carolina (Adams et al., 1990).
North Carolina Distribution: This
species is found in the Chowan River,
Roanoke and Pee Dee River systems in
North Carolina (Shelley, 1983; Adams et
al., 1990; Table 2).
Description: Shell shape is elliptical,
oblong to ovate in outline, approaching
sub cylindrical in cross-section, shell
thickness rather solid, with a pronounced
thickening of the anterior ventral margin
from about the middle of the shell
anterior, inflated, shell length reaching
about 142 mm. Anterior margin of the
shell is narrowly rounded, the ventral
margin straight, with a straight dorsal
margin, the posterior margin bluntly
pointed slightly below the midline. The
posterior ridge is rounded and generally
double, ending posteriorly in a
biangulation slightly below the midline.
Beaks are moderately full and slightly
raised above the hingeline, beak
sculpture consists of 5-7 straight bars
running parallel with the hingeline or
slightly curved. The shell surface is
marked by irregular growth lines, which
may form ridges, surface varies from
smooth almost shiny to rough.
This is a typical Anodonta completely lacking any indication of pseudocardinal or lateral teeth. The beak cavity is open and relatively shallow. Periostracum is yellowish brown, greenish brown, to reddish brown becoming dark brown to black with age, immature specimens have fine green rays. Nacre color varies from white, salmon or purple and almost always darker in the beak cavity. Life History and Ecology: The Alewife Floater is found living in ponds, overbank pools, streams and rivers in a variety of substrates including silt, sand and gravel. The distribution is closely tied to the distribution of its host fish. Nedeau et al. (2000) report this species is bradytictic, a long-term brooder, with eggs being fertilized in August and glochidia being released the next spring. The Alewife (Alosa pseudoharengus) has been reported as a host fish for this mussel (Davenport and Warmuth, 1965). Status: Currently Stable (Williams et al., 1993:10). This species is considered State Threatened in North Carolina. Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina
Cyclonaias tuberculata
(Rafinesque, 1820) Purple Wartyback
Plate 2, Figure 9
Synonymy: Obliquaria (Rotundaria) tuberculata Rafinesque, 1820; Rafinesque, 1820:103
Type Locality: Ohio River and its tributaries. General Distribution: Upper Mississippi River drainage generally; Lake St. Clair drainage, and from Pennsylvania northwest to southern Michigan and northwestern Wisconsin (Mathiak, 1979), south to Iowa, Missouri, and Arkansas. In Canada, Lake Erie and the Sydenham River in southern Ontario (Clarke, 1981a). It occurs throughout the Tennessee and Cumberland river drainages. North Carolina Distribution: This species is restricted to the New River, Allegheny County, in North Carolina (Table 3). Description: The shell is compressed (among specimens in streams) to slightly inflated (among specimens in large rivers), solid, subquadrate to circular in outline. Mature individuals may attain a length of 130 mm. Beaks are depressed (in stream forms) to moderately swollen, rather prominent (in large river forms); sculpture consists of numerous fine, irregular, broken ridges, each made up of alternating zigzag bars and loops which continue down the valve until the nodules appear; there is often a shallow, narrow furrow or depression centrally on the umbonal area. A wing like depression above the low dorsal ridge, more extensive in stream forms. Center and posterior surfaces are covered with rounded or elongated tubercles that parallel the growth lines; tubercles are more numerous in stream forms. The anterior end and ventral margins are broadly rounded; the posterior end is occasionally rounded, usually squarely or obliquely truncated. The left valve has two narrow but heavy, divergent pseudocardinal teeth, deeply serrated between, sometimes almost meeting anteriorly; the two lateral teeth are short, heavy, and slightly curved. The right valve has a single, massive, ragged, slightly triangular-shaped pseudocardinal tooth, usually with a small tubercular tooth on either side. The beak cavity is compressed and deep; the interdentum is wide and flat. The periostracum is a dull yellowish brown to dark brown; young shells occasionally have traces of greenish rays. The nacre varies from a uniform deep purple, often with a coppery tinge along the margin, to light purple with the center (within the pallial line) nearly white; the posterior margin is iridescent (Parmalee and Bogan 1998:68-69). Life History and Ecology: This mussel typically inhabits a gravel/mud bottom, usually in areas of current or riffles; in water less than two feet in depth, but can occur at depths up to 20 feet. The species is tachytictic, and the reproductive period lasts from June to August. Initial studies by Hove et al. (1994) showed the Channel Catfish (Ictalurus punctatus) and Yellow Bullhead (Ameiurus natalis) as suitable hosts for glochidia of this mussel. Additional testing of the yellow bullhead confirmed it as a valid host species (Hove et al., 1994). Subsequently, Hove (1997) has reconfirmed the channel catfish as a host species and has added two new host species for the glochidia of the Purple Wartyback: the Flathead Catfish (Pylodictis olivaris) and the Black Bullhead (Ameiurus melas) (Parmalee and Bogan, 1998). Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina
Status: Special Concern (Williams et al., 1993:11). This species is by the Natural Heritage Program as significantly rare in North Carolina. Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina
Elliptio cistellaeformis (Lea, 1863) Box Spike
Plate 2, Figure 10
Synonymy:
Unio cistellaeformis Lea, 1863; Lea, 1863:192 Type Locality: Neuse River, near Raleigh, North Carolina. General Distribution: Restricted to the Atlantic river basins from the Catawba to the Pamlico River basins in North Carolina (Table 2). North Carolina Distribution: This species is found in the Catawba, Pee Dee Lumber, Cape Fear, Neuse, Pamlico River basins in North Carolina (Table 2). Description: “Shell smooth, oblong, very much inflated, flattened at the side, inequilateral, obtusely angular behind, rounded before; substance of the shell somewhat thick; beaks somewhat prominent; ligament rather short and dark brown; epidermis dark brown, without rays, with rather close marks of growth; umbonal slope swollen and rounded; posterior slope broad, flattened, scarcely carinate; cardinal teeth small, tuberculate, double in both valves; lateral teeth rather long, lamellar and nearly straight; anterior cicatrices distinct, large and will impressed; posterior cicatrices confluent, large and slightly impressed; dorsal cicatrices placed over the centre of the cavity of the beaks; cavity of the shell deep and wide; cavity of the beaks rather shallow and rounded; nacre white and iridescent: (Lea, 1863:19-20). The shell is very inflated with a very straight ventral margin. Life History: The host fish for the glochidia of this species is unknown. It is found along the banks often among the tree roots.
Status: Williams et al. (1993:11) listed the status as unknown. Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina
Elliptio complanata
(Lightfoot, 1786) Eastern Elliptio
Plate 2, Figure 11
Synonymy: Mya complanata Lightfoot, 1786; Lightfoot, 1786: 100, No. 2190 Comment: Johnson (1970) lists an extensive synonymy for this species. The taxonomy of this species in the southern end of its range becomes very confusing and many of the shell shapes have names but will not be dealt with here.
Type Locality: Maryland. Johnson
(1948) restricted the type locality to:
Potomac River, Washington, District of
Columbia [approximately opposite
Fairfax Co. Virginia].
General Distribution: Altamaha River
Basin of Georgia, north to the St.
Lawrence River Basin, west in the
Interior Basin west to Lake Superior and
parts of the Hudson Bay Basin.
North Carolina Distribution: This
species is wide spread in the Atlantic
Slope rivers in North Carolina from the
Chowan south to the Broad River. It is
introduced into the French Broad River
in Buncombe County (T. Savidge, Pers.
Comm. March 2002) (Table 2).
Description: Shell shape is trapezoidal
to rhomboid or subelliptical, compressed
to inflated, shell thickness varies from
thin to solid, length 120 mm. Anterior
margin is rounded, dorsal and ventral
margins are roughly parallel, ventral
margin is often straight, posterior margin
broadly rounded ending at or near the
base in a point or biangulation.
Posterior ridge is broad and double and
rounded to angular. The posterior slope
is flat. Beaks are low and uninflated,
beak sculpture consists of 5-6 ridges, the
first two or three curved and
subconcentric, the rest run parallel to the
growth lines, nearly straight in the
middle and curved up at both ends.
Surface with irregular growth lines and
varies from smooth to mat.
Left valve has two ragged pseudocardinal teeth and two nearly straight lateral teeth. Right valve has a single pseudocardinal tooth and a single lateral tooth. Interdentum is essentially absent. Beak cavity is shallow. Periostracum is yellowish to brown and blackish, young specimens with indistinct greenish rays present. The rays generally disappear in older shells. Nacre varies from white, pink, salmon, to various shades of purple. Life History and Ecology: Ortmann (1919:109) commented that the Eastern Elliptio “apparently has no ecological preferences, being found practically in any permanent body of water; in canals and reservoirs with quiet water and muddy bottom, as well as in large rivers with strong current and heavy gravel and rocks. In the small creeks it goes up very far into the headwaters”. Elliptio complanata is tachytictic, gravid females have been found from late April through the middle of July. The females expelled their glochidia in conglutinates (Ortmann, 1919). The Banded Killifish (Fundulus diaphanus), Green Sunfish (Lepomis cyanellus), Largemouth Bass (Micropterus salmoides), White Crappie (Pomoxis annularis), and Yellow Perch (Perca flavescens) have been listed as hostfish for the glochidia for this mussel (Watters, 1994:103). Status: Currently Stable (Williams et al., 1993:11). Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina
Elliptio congaraea (Lea, 1831) Carolina Slabshell
Plate 2, Figure 12
Synonymy: Unio congaraeus Lea, 1831; Lea, 1831:72, pl. 6, fig. 4
Type Locality: Congaree River, South
Carolina
General Distribution: This species is
known from the Ogeechee River system
in Georgia north to the Pamlico River
system of North Carolina (Johnson,
1970; Table 2).
North Carolina Distribution: Elliptio
congaraea is known from the Pamlico,
Neuse, Cape Fear and Pee Dee River
systems in North Carolina (Johnson,
1970; Table 2).
Description: “Shell rhomboid,
subcompressed, rather thin to subsolid,
somewhat inequilateral; beaks
moderately full and slightly elevated; the
sculpture consisting of parallel
undulations, posterior ridge high and
angled, double below, the greatest
diameter of the shell being along its line;
in front of it the shell is wedge-shaped;
basal line nearly straight; posterior end
obliquely truncated above, somewhat
biangulate below; surface with irregular
growth lines, wrinkled on the dorsal
slope; epidermis dirty greenish-yellow or
tawny, generally rayed, especially in
young shells, scarcely shining; left valve
with two ragged, subcompressed
pseudocardinals and two delicate
laterals; right valve with two
pseudocardinals, the upper small, and
one lateral; beak cavities not deep;
muscle scars superficial; nacre purplish,
often lurid in the shell cavities.”
(Simpson 1914:615).
Life History: The host fish for the
glochidia of this species is unknown.
Status: Williams et al. (1993:11) listed
as special concern. This species is not
State listed in North Carolina at this time. Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina
Elliptio dilatata
(Rafinesque, 1820) Spike
Plate 3, Figure 13
Synonymy: Unio (Eurynia) dilatata Rafinesque, 1820; Rafinesque, 1820:297
Type Locality: Unio dilatatus: no type
locality published, but generally
considered to be Ohio River.
General Distribution: Entire
Mississippi River drainage from the St.
Lawrence River and its tributaries south
to northern Louisiana and west to the
tributaries of the Red River, Oklahoma.
Howells et al. (1996) report a single
locality on the San Marcos River in
Texas. With reference to Canada,
Clarke (1981a:268) states that the Spike
is “[c]ommon in the Great Lakes and
their tributaries from Lake Michigan to
Lake Erie; uncommon in Lake Ontario
and in the St. Lawrence
River.”(Parmalee and Bogan, 1998).
North Carolina Distribution: The
Spike is known form the Hiwassee,
Little Tennessee, French Broad and New
River basins in North Carolina
(Ortmann, 1918; Table 3)
Description: The shell is compressed to
slightly inflated, attenuate, solid, and
thick. Mature individuals inhabiting
impounded stretches of large rivers
become especially large and develop
extremely thick shells, many attaining a
length of 120 mm. Beaks are depressed
and flattened; sculpture consists of 4–5
pronounced loops, running parallel with
the growth lines. The anterior end is
broadly rounded, the ventral margin is
straight or slightly curved, and the
posterior end is sharply pointed and
often compressed behind the strongly
developed, rounded posterior ridge.
Concentric rest lines are often
prominent.
The left valve has two triangular, divergent, compressed pseudocardinal teeth, usually roughened or finely serrated; the two lateral teeth are heavy, rough, widely separated, and the inner surface is usually rough. The right valve has a heavy, triangular pseudocardinal tooth; the lateral tooth is low, thick, and roughened. The interdentum is moderately wide; the beak cavity is usually very shallow or absent. Periostracum of young shells is light brown, greenish, or yellowish green, often faintly rayed; old valves are dark greenish brown to black. The nacre varies from white through salmon to deep purple (Parmalee and Bogan 1998:80). Life History and Ecology: Elliptio dilatata is somewhat generalized relative to the size of rivers, which it inhabits, and depths at which it may occur. A firm substrate composed of coarse sand and gravel with moderately strong current appears to provide the most suitable habitat, but also can be found in soft mud. Baker (1928) indicated the species was tachytictic, the reproductive season occurring from mid-May to August. The Gizzard Shad (Dorosoma cepedianum), Flathead Catfish (Pylodictis olivaris), White Crappie (Pomoxis annularis), Black Crappie (P. nigromaculatus), and the Yellow Perch (Perca flavescens) have been listed by Fuller (1974) as host species for the glochidia. Under laboratory conditions Luo (1993) was able to infect the Rainbow Darter (Etheostoma caeruleum), Banded Sculpin (Cottus carolinae), and Rockbass (Ambloplites rupestris) with glochidia of the Spike (Parmalee and Bogan, 1998). Status: Currently Stable (Williams et al., 1993:11). This species is listed as State Special Concern in North Carolina. Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina
Elliptio folliculata (Lea, 1838) Pod Lance
Plate 3, figure 14
Synonymy: Unio folliculatus Lea, 1838; Lea, 1838:38, pl. 11, fig. 33
Type Locality: Savannah River, Georgia
(Lea, 1838)
General Distribution: the Pod Lance
ranges from the Savannah River north to
the Waccamaw and Cape Fear River
basins in North Carolina (Johnson, 1970;
Table 2).
North Carolina Distribution: This
species is found in the Cape Fear,
Waccamaw and Pee Dee River basins.
(Table 2)
Description: This is a narrow,
uninflated, elongated naiad that in its lake
form resembles a straight-edged razor.
The umbo is flat and the dorsal and
ventral shell margins are parallel to each
other. The anterior-dorsal margin is
angular in shape. The shell is covered by
a rough dark-brown to black
periostracum. The shell nacre of inner
shell surface varies from bluish to pink.
The hinge has pyramidal pseudo-cardinal
teeth.
The original description by Lea (1838) is
as follows: "Shell narrow-elliptical, very
transverse, very inequilateral,
subbiangular behind, rounded before,
rather compressed, flattened at the side;
substance of the shell rather thin; beaks
scarcely prominent; ligament long and
curved; epidermis very dark brown;
cardinal teeth small and lobed; lateral
teeth long and somewhat curved; anterior
cicatrices distinct; posterior cicatrices
confluent; dorsal cicatrices in the center
of the cavity of the beaks; cavity of the
shell small; cavity of the beak very small;
nacre purple and iridescent." (Adams et
al., 1990).
Life History: As in all Elliptio species,
the cream colored marsupium of the female extends along the ventral margin of the entire outer demibranch. Habitat depth ranged between 1.4-3.0 m in the lake. Host fish for the glochidia of this species is unknown. Generally the species was found in a sand substrate at greater than one-meter depths in Lake Waccamaw waters (Porter, 1985). Specimens from Big Creek and Waccamaw River were collected in conditions similar to that from Lake Waccamaw except that some downstream Waccamaw River specimens were extracted from a clay bank in a semi-swift flowing river segment. On the other hand, the Orton Pond canal habitat was a muddy high-sided bank with considerable vegetation near by in sluggishly moving water This species, like most Elliptio sp., is believed to be tachytictic (short-term breeder). Of the few specimens collected in Lake Waccamaw waters during the 1978-1981 sampling period (Porter, 1985), gravid conditions were seen only in June, 1980 and August, 1980. Since then, gravid specimens have been collected in July (1986) from a canal exiting Orton Pond, Brunswick County, North Carolina (Adams et al., 1990) Status: Williams et al. (1993:11) listed as special concern. This species is listed as Sate Special Concern in North Carolina. Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina
Elliptio icterina (Conrad, 1834) Variable Spike
Plate 3, Figure 15
Synonymy: Unio icterinus Conrad, 1834; Conrad, 1834:41, pl. 6, fig. 5
Type Locality: Muddy shore, Savannah
River opposite Augusta [Richmond Co.]
Georgia (Johnson, 1970).
General Distribution: St. Marys River
of Florida north to the Chowan River
system in Virginia (Johnson, 1970;
Table 2).
North Carolina Distribution: This
species is found in from the Broad River
basin north to the Roanoke River basin
(Johnson, 1970; Table 2).
Description: “Shell oblong, subelliptical
or subrhomboid, convex, solid,
inequilateral; beaks moderately full and
elevated, their sculpture a number of
strong concentric ridges; posterior ridge
prominent, somewhat double, ending
behind in a narrow faint biangulation at
or below the median line; surface nearly
smooth; epidermis greenish-yellow to
tawny or tawny-brown, usually showing
dark rest marks, scarcely rayed,
shinning; pseudocardinals
subcompressed to solid, rough; laterals
long, curved; muscle scars large,
impressed; nacre white often silvery, a
little thicker in front.” (Simpson,
1914:665).
Life History: No host fish are known
for the glochidia of this species.
Status: Williams et al. (1993:11) listed
as currently stable. Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina
Elliptio judithae Clark, 1986 Neuse Slabshell
Not figured
Synonymy: Elliptio judithae Clark, 1986; Clarke, 1986:78-96
Type Locality: The holotype is from the
Neuse River at Seven Springs, Wayne
County, North Carolina. Paratypes are from
the Neuse River above the U. S. Route 301
bridge near Smithfield, Johnston County, and
at Milburne, 7 miles east of Raleigh, in Wake
County. (Adams et al., 1990).
General Distribution: Restricted to the
Neuse River, North Carolina.
North Carolina Distribution: Known
definitively only from the Neuse River at
Milburne (Wake County), Smithfield
(Johnston County), and Seven Springs
(Wayne County). Conchologically
similar shells collected from the Tar
River below Rocky Mount probably
belong to this species. (Adams et al.,
1990).
Description: The Neuse Slabshell is a
freshwater mussel with an appressed,
elliptical shell. Specimens up to about 85
mm in length have been collected.
Height of the shell is about 48% of the
length and the valves are thin. The shell
is sculptured with plicate ridges, each
about 1.5 mm to 3.0 mm wide, and the
periostracum is glossy. The shell is
generally yellowish to dark brown with
faint, narrow green rays. The hinge teeth
are complete, the pallial line distinct, and
the nacre pale purple. Morphs of other
Elliptios may share some of these
characteristics, however, soft-part
anatomy of Elliptio judithae will serve to
distinguish it from such specimens. E.
judithae has coronate incurrent papillae
and irregularly-developed brachial septa,
characters not known to be shared by any
other Elliptio. A complete description
and photographs of the species can be
found in Clarke (1986) (Adams et al.,
1990).
Life History: Nothing is known of the life history and ecology of the species. Its fish host is unknown. The holotype was collected in water 0.15 m deep on a sand bar in the middle of the Neuse River, which was about 100 m wide at the site. Status: Williams et al. (1993) did not list this species but assumed it was a synonym of Elliptio roanokensis. Remarks. Recently, J. M. Alderman collected a gradating series of specimens of Elliptio roanokensis from the Tar River near Tarboro, North Carolina, and found that the smaller specimens bore striking conchological and soft-tissue similarity to E. judithae. This raises the possibility that our species concept of E. judithae, as defined by Clarke (1986), needs to be reassessed (Adams et al., 1990).Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina
Elliptio lanceolata (Lea, 1828) Yellow Lance
Plate 3, figure 16
Synonymy: Unio lanceolatus Lea, 1828; Lea, 1828:266, pl. 3, fig. 2
Type Locality: Tar River at Tarborough
[Edgecombe County], North Carolina
(Johnson, 1970).
General Distribution: The yellow lance
is known from the Tar, Roanoke, James,
and Rappahannock drainages (A.
Gerberich, pers. comm.) (Adams et al.,
1990).
North Carolina Distribution: the
Yellow Lance is restricted to the Pamlico
and Neuse River systems (Table 2).
Description: This elongate, freshwater
mussel grows to approximately 86 mm
long. Shells are over twice as long as tall.
The periostracum is usually bright yellow
over the entire surface in younger
individuals. Older individuals may have a
brown discoloration at the posterior end
of the shell. (Uniformly brown
individuals are also found; however,
yellow and brown individuals are not
found at the same stations.) The nacre
may range from salmon to white to an
iridescent blue color. The posterior ridge
is distinctly rounded and curves dorsally
toward the posterior end. Rays are
usually never present; however, one
individual has been observed with three
wide, prominent green rays on the
posterior third of the shell in the Tar
River Drainage Basin (Adams et al.,
1990). Brownish growth rests are clearly
evident on the periostracum. The pallial
line and adductor muscle scars are
distinct. The posterior adductor muscle
scars are less impressed than the anterior
adductor muscle scars. The lateral teeth
are long - two on the left valve and one
on the right valve. Two pseudocardinal
teeth are on each valve. On the left valve
one is before the other with the posterior tooth tending to be vestigial. On the right valve, the two pseudocardinal teeth are parallel with the more anterior one rather vestigial. (Adams et al., 1990) Life History: Elliptio lanceolata prefers clean, coarse to medium size sands as substrate. On occasion, specimens are also found in gravel substrates. This species is found in the main channels of drainages down to streams as small as three feet across. Gravid females have been found in the Tar River Drainage Basin in June (Alderman, unpubl. data). As verified by Tankersley (1988), the glochidia are hookless. The fish host for this species has not been determined. Status: Williams et al. (1993:11) listed as endangered. The existence of the Yellow Lance in the Roanoke Drainage Basin has not been verified in recent years. In the Tar River, this species has declined (Alderman 1988) since A. Clarke (1983) completed his survey for the Tar River spiny mussel (Adams et al., 1990). This species is listed as State Endangered effective July 1, 2002. Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina
Elliptio marsupiobesa Fuller, 1972 Cape Fear Spike
Plate 3, Figure 17
Synonymy: Elliptio marsupiobesa Fuller, 1972; Fuller, 1972:1-10
Type Locality: Cape Fear River, 0.1
miles downstream from Carvers Creek,
Cumberland County, North Carolina.
General Distribution: Elliptio
marsupiobesa is only known from the
Cape Fear River, North Carolina.
North Carolina Distribution: Elliptio
marsupiobesa is only known from the
Cape Fear River in Cumberland and
Bladen counties
Description: The Cape Fear spike may
reach about three inches in length. The
anterior third of the shell is considerably
thicker than the posterior third, and the
shell appears to significantly thicken as
individuals grow. The shell is distinctly
wedge shaped without sexual
dimorphism. The swollen posterior ridge
is keeled and the posterior slope is narrow
and concave. Adults have one or two
radial grooves on the posterior slopes.
Growth rests are clearly expressed in the
shells. The periostracum of young
individuals is smooth with a shiny,
yellow-brown color. Green rays may be
present on the posterior half of the shell.
Older individuals are a dark brownish-
black with roughened margins and
posterior slopes. (Adams et al., 1990).
Life History: As provided by Fuller
(1972), the Cape Fear spike was found in
muddy, loose, sandy substrates below
logjams. It was not found in firm, sandy
substrates. Fuller (1972) found gravid
females around the middle of June.
Nothing is known about the fish hosts or
ecology of the species (Adams et al.,
1990).
Status: Williams et al. (1993:1) listed as currently stable. This species is listed as State Special Concern. Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina
Elliptio roanokensis (Lea, 1838) Roanoke Slabshell
Plate 3, Figure 18
Synonymy: Unio roanokensis Lea, 1838; Lea, 1838:27, pl. 8, fig. 21
Type Locality: Roanoke River, between
Tarboro, North Carolina and Norfolk,
Virginia.
General Distribution: According to
Walter (1954) the Roanoke Slabshell
ranges from the Connecticut River in
Massachusetts to the Savannah River in
Georgia.
North Carolina Distribution: This
species is found in the Cowan, Roanoke,
Pamlico, Neuse, Cape Fear and Pee Dee
River systems (Table 2).
Description: Individual Roanoke
Slabshells grow to greater than 150 mm
total length. In North Carolina it is one
of our largest freshwater mussel species.
Of 13 specimens recently examined from
the Tar River, the height to length ratio
ranged from .458 to .544, and the width
to length ratio ranged from .212 to .283.
The posterior ridge varies from being
well defined to being uniformly rounded.
The periostracum is generally smooth
except near the margins of the shell.
Growth rests are distinct. Color of the
periostracum is usually a yellow-reddish-
brown, which darkens with age. Narrow
greenish rays are often present from the
anterior end of the shell to the posterior
ridge. The rays are less distinct in larger
individuals. The nacre is usually
purple(Adams et al., 1990).
Life History: Little is known of the life
history and ecology of this species. In the
Tar River, the Roanoke Slabshell is
usually found associated with the deeper
channels near shore in relatively fast
flowing water. The substrate consists of
coarse to medium sized sands and small
gravel (Alderman, unpubl. data) (Adams
et al., 1990).
Status: Williams et al. (1993:11) listed as special concern. This species is listed as State Threatened. Remarks: Johnson (1970) considered the Roanoke Slabshell to be one of the many forms of Elliptio complanata found throughout the southern Atlantic Slope Region. However, the Roanoke Slabshell has a centrally plicate shell, certain of the incurrent papillae being subdivided into smaller papillae, and irregularly developed branchial septa. These characteristics distinguish the Roanoke Slabshell from Elliptio complanata. Clarke (1986) described Elliptio judithae from the Neuse River. His description of the species matched that of smaller individual Roanoke Slabshells (Adams et al., 1990). Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina
Elliptio steinstansana
Johnson and Clarke, 1983 Tar River Spinymussel
Plate 4, Figure 19
Synonymy: Elliptio steinstansana Johnson and Clarke, 1983; Johnson and Clarke, 1983:289-298
Type Locality: Near Tarboro in
Edgecombe County, North Carolina
General Distribution: This species is
found in the Pamlico and in the lower
Neuse River basins of North Carolina
(Johnson and Clarke, 1983, J. Alderman,
Pers. Comm.).
North Carolina Distribution: The Tar
River Spinymussel is restricted to the
Tar River basin and one site on a
tributary in the lower Neuse River Basin
(Johnson and Clarke, 1983; Alderman,
1988; J. Alderman, Pers. Comm.).
Description: This small, subrhomboid
mussel grows to approximately 60 mm
long. Short spines (up to 5 mm long) are
found on most specimens. As many as
12 spines have been found on juveniles;
however, adults tend to lose some of their
spines as they mature. In general, spines
arranged in a radial row slightly anterior
of the posterior ridge on one valve are
symmetrically positioned with the spines
on the opposite valve. Some individuals
may have two rows of spines on each
valve. The smooth, orange-brown to dark
brown periostracum may be rayed in
younger individuals. The shell is
significantly thicker toward the anterior
end, and the nacre is usually pink in this
area. The posterior end of the shell is
thinner with an iridescent bluish white
color. Two or more linear ridges,
originating within the beak cavity and
extending to the ventral margin, can be
found on the interior surface of the shell.
The distance between these ridges widens
toward the ventral margin. Johnson and Clarke (1983) provide additional descriptive material. Life History: It appears that the Tar River Spinymussel's preferred habitat includes the following: relatively fast flowing, well oxygenated, circumneutral pH water; relatively silt-free, uncompacted, gravel/coarse sand substrate; sites prone to significant swings in water velocity (Adams et al., 1990). The Tar River spiny mussel is probably a tachytictic reproducer with gravid females present at some time from April through August (Widlak 1987). The glochidia have not been described and the fish host is unknown. Status: Williams et al. (1993:11) listed as endangered. This species is federally and state listed as Endangered. The U.S. Fish and Wildlife Service has developed a recovery plan for this species (U.S. Fish and Wildlife Service, 1992). Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina
Elliptio waccamawensis
(Lea, 1863) Waccamaw Spike
Plate 4, Figure 20
Synonymy:
Unio waccamawensis Lea, 1863; Lea, 1863:193 Type Locality: Lake Waccamaw, North Carolina General Distribution: This species is restricted to the Waccamaw basin in North Carolina and South Carolina (Johnson, 1970; Heard, 1975; Adams et al., 1990). North Carolina Distribution: The Waccamaw Spike is restricted to the Waccamaw Lake and River in North Carolina (Johnson, 1970; Porter and Horn, 1984a; Adams et al., 1990, Table 2). Description: This naiad has a moderately inflated elliptical shell with a prominent angular ridge on its posterior slope. The ventral margin is straight. The umbo has a trapezoidal beak sculpture. Pseudo-cardinal teeth are present on the hinge and variable in shape. There is a white to bluish nacre on the inner shell surface. A light to dark brown smooth periostracum covers the outer shell surface. "Shell smooth, triangular, inflated, flattened at the sides, very inequilateral, subbiangular behind, rounded before; valves thin; beaks prominent; epidermis brownish green or olivaceous, obscurely rayed; cardinal teeth very small, compressed, oblique, double in both valves; lateral teeth long, lamellar and straight; nacre bluish white and iridescent." (Lea, 1863) (Adams et al., 1990). Life History: Glochidia are suboval, hookless and marginally bilaterally asymmetrical in shape. Its hinge varies from straight to slightly concave in
appearance. Dimensions, as reported in Porter and Horn (1980) are: length = 0.210 mm; height = 0.217 mm; hinge length = 0.144 mm; hinge length/length ratio = 0.69; height/length ratio = 1.04; and hinge length/height ratio = 0.66. This is a short-term breeder (tachytictic). Time of its reproductive cycle does vary from season to season. Marsupia have been observed from April into August. Glochidia have been found in May through July. Host fish for the glochidia are unknown. The 1978-1981 survey (Porter, 1985) found large numbers of E. waccamawensis throughout the lake including in the deepest depths where the substrate is peat. Average density of the species in the lake was 22.79/m2. Highest recorded density was 132.3/m2. Densities of E. waccamawensis were positively correlated with light penetration and pH; densities were negatively correlated with: sediment pheo-pigment and mean sediment size (0/ units). Elliptio waccamawensis densities were lower within beds of the emergent plants Maidencane and Spatterdock than in areas not containing Maidencane and Spatterdock (Adams et al., 1990). Status: Williams et al. (1993:11) listed as special concern. This species is listed as State Endangered effective July 1, 2002. Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina
Epioblasma capsaeformis
(Lea, 1834) Oyster Mussel
Plate 4, Figure 21
Synonymy: Unio capsaeformis Lea, 1834; Lea, 1834:31, pl. 2, fig. 4
Type Locality: Cumberland River,
Tennessee.
General Distribution: Found
throughout the Tennessee River system
in Virginia, Tennessee, North Carolina,
and northern Alabama, and in the
Cumberland River system in Kentucky
and Tennessee (Johnson, 1978).
North Carolina Distribution: This
species is known historically from the
French Broad River in Ashville,
Buncombe County (Ortmann, 1918).
Description: The shell is elliptical or
irregularly obovate in outline and of
medium size: maximum length is about
70 mm. Valves are subsolid and
somewhat inequilateral. Beaks are
moderately full and elevated, located
slightly anterior of the middle of the
shell in males and within the anterior
third of the shell in females; the
sculpture is feeble, consisting of 2–4
faint parallel loops discernible only in
very young juveniles. The surface of the
shell is covered with irregular growth
lines. The hinge ligament is short. The
dorsal shell margin is straight, and the
anterior end is regularly rounded; the
posterior end of males is slightly
protruding; females are more broadly
rounded. The ventral margin in males is
slightly curved; in females, it is straight
and anterior to the sulcus, but behind the
sulcus there is a pronounced, rounded
marsupial swelling extending well below
the base. Marsupial swelling is thin,
slightly inflated, often offset from the
rest of the shell by an anterior and
posterior sulcus, sometimes toothed along the margin. Male shells are almost regularly elliptical, with a double posterior ridge, slightly biangulate behind. Female shells are obovate with a distinct thin, slightly inflated marsupial swelling, darker than the rest of the shell. The left valve has two small, triangular, subcompressed pseudocardinal teeth, a narrow interdentum, with two short, slightly curved lateral teeth. The right valve has a single stout, triangular, subcompressed pseudocardinal tooth, sometimes with a small tooth on either side, a narrow interdentum, and a single short, slightly curved lateral tooth. The beak cavity is shallow; anterior adductor muscle scars are small, well-impressed; posterior adductor muscle scars are longer and shallow. The pallial line is distinct anteriorly, fading posteriorly. The periostracum subshiny, yellowish green, with fine green rays over entire shell. The marsupial swelling of the female is usually dark green, sometimes almost black. The nacre color is bluish white to creamy. (Parmalee and Bogan, 1998). Life History and Ecology: The Oyster Mussel can be found living in shallow riffles in fast water less than three feet in depth in a gravel and sand substrate. S. A. Ahlstedt (pers. comm., 1992) noted that the Oyster Mussel females, when releasing glochidia, move up onto the surface with the ventral margin uppermost, the mantle margins being visible at some distance. Ortmann (1924:53) observed that the “pad” of the mantle margin in females collected from the Duck River was “grayish to blackish, and never of the peculiar bluish or greenish-white so often seen in upper Tennessee specimens.” The Oyster Mussel is a long-term brooder (bradytictic): gravid individuals have Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina
been observed from early spring into fall. Fish species identified as hosts for the glochidia include the Spotted Darter (Etheostoma maculatum), Redline Darter (E. rufilineatum), Dusky Darter (Percina sciera), Banded Sculpin (Cottus carolinae) (Yeager, 1987; Neves, 1991), and Wounded Darter (E. vulneratum) (Yeager and Saylor, 1995) (Parmalee and Bogan, 1998). Status: Endangered (Williams et al., 1993:11). The Oyster mussel is federally and State listed as endangered. Adams et
al. (1990) presumed this species is extirpated in North Carolina. Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina
Fusconaia barnesiana (Lea, 1838) Tennessee Pigtoe
Plate 4, Figure 22
Synonymy: Unio barnesianus Lea, 1838; Lea, 1838b:31, pl. 10, fig. 26
Type Locality: Cumberland River,
Tennessee.
General Distribution: Cumberland and
Tennessee River systems (Simpson,
1914).
North Carolina Distribution: This
species is known only from the
Hiwassee and Little Tennessee River
basins (Table 3).
Description: The shell of Fusconaia
barnesiana is highly variable in outline,
dimension, color, and pattern, factors
that resulted in the recognition of three
subspecies, which may in reality reflect
a headwaters-to-big-river cline and
individual variations.
Shells of Fusconaia barnesiana are
strong, occasionally very thick and
heavy, oval, and somewhat truncated to
triangular in outline, especially in F. b.
bigbyensis. Mature specimens may reach
a length of 90–95 mm. The posterior
ridge is usually distinct but typically
rounded; the anterior and ventral
margins are broadly rounded, while the
posterior margin is straight. Beaks are
only slightly inflated to rather high and
full. The surface is usually evenly
roughened with fine, uneven growth
lines.
The left valve has two erect
pseudocardinal teeth; the more dorsal
one is often short and triangular, and the
anterior tooth is elongated and bladelike.
The two lateral teeth are moderately long
and straight; in some individuals they are
relatively short, slightly curved, and
widely separated. The right valve has a
large, erect, elongated pseudocardinal tooth, usually with a smaller low tooth on either side; the lateral tooth is long and straight, sometimes with a second low tooth present. Often the pseudocardinal teeth project ventrally at a 90° angle from the lateral teeth. The beak cavity is shallow to nearly wanting; the interdentum is usually wide. Muscle scars are deeply impressed. The periostracum of juveniles is a dull yellowish olive or brown with a satiny appearance, becoming dark brown to blackish with age. Some individuals are marked with a few to many dark green rays. The nacre color is white, and some specimens have a faint salmon wash (Parmalee and Bogan, 1998). Life History and Ecology: The Tennessee Pigtoe is probably tachytictic, spawning in late spring and being gravid into midsummer, based on data for other species of Fusconaia (F. cor and F. cuneolus) found living in the same rivers and under the same habitat conditions as F. barnesiana (Neves, 1991). Host fish for the glochidia unknown (Parmalee and Bogan, 1998). Status: Special Concern (Williams et al., 1993:11). This species is listed as State Endangered, effective July 1, 2002. Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina
Fusconaia masoni (Conrad, 1834) Atlantic Pigtoe
Plate 4, Figure 23
Synonymy: Unio masoni Conrad, 1834; Conrad, 1834:34, pl. 5, fig. 2
Type Locality: Savannah River,
Augusta, [Richmond Co.] Georgia
(Johnson, 1970).
General Distribution: The Atlantic
Pigtoe ranges from the Ogeechee
Drainage Basin, Georgia north to the
James Drainage Basin, Virginia. In
North Carolina, this species was once
found in every Atlantic drainage except
the Cooper-Santee and Waccamaw
drainage basins (Johnson 1970).
North Carolina Distribution: This
species is known from the Catawba, Pee
Dee, Cape Fear, Neuse, Pamlico, and
Roanoke River basins (Aarons Creek)
(Johnson, 1970; Table 2).
Description: Atlantic Pigtoes are sub-
rhomboidal except in individuals from
headwater areas. Such individuals tend
to be more elongate. The posterior ridge
is very distinct, and the umbos extend
well above the dorsal margin. The
periostracum is yellow to dark brown and
parchment like. The nacre ranges from
an iridescent blue, to salmon, to white, to
orange. Pseudocardinal and lateral teeth
are well developed except for the anterior
pseudocardinal tooth in the right valve,
which is vestigial. All four demibranchs
serve as marsupia in gravid females. As
the glochidia mature, the demibranchs
and adductor muscles develop a bright
orange-red to red color. Additional
species descriptions can be found in
Johnson (1970) and Fuller (1973).
Life History: The preferred habitat for
the Atlantic Pigtoe is a yielding substrate
composed of coarse sands and gravel at
the downstream edge of riffle areas. In such habitats, which are becoming increasingly rare since sedimentation significantly affects such areas, as many as five live individuals have been found in a one-meter square area. This species is less common in sands, cobble, and mixed substrates of sand, silt, and detritus. Little is known about other aspects of its life history or ecology (Adams et al., 1990). Watters and O’Dee (1997) identified the Bluegill (Lepomis macrochirus) and the Shield Darter (Percina peltata) as potential fish hosts for Fusconaia masoni glochidia. Status: Williams et al. (1993:11) listed as threatened. This species is listed as State Endangered, effective July 1, 2002. Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina
Fusconaia subrotunda (Lea, 1831) Long-solid
Plate 4, Figure 24
Synonymy: Unio subrotundus Lea, 1831; Lea, 1831:117, pl. 18, fig. 454
Type Locality: Ohio
General Distribution: Ohio,
Cumberland, and Tennessee River
systems (Simpson, 1914:893).
North Carolina Distribution: This
species is reported from the Hiwasssee
and French Broad rivers (Ortmann,
1918; Table 2).
Description: The big river form of
Fusconaia subrotunda has a shell that is
oval to broadly elliptical or oblong in
outline, solid, and inflated. Beaks are
high, full, and turned forward over the
lunule; sculpture consists of a few
subnodular ridges or wrinkles. The
anterior margin is broadly rounded, and
the ventral and posterior margins are
slightly curved to nearly straight; lacking
a distinct posterior ridge, the dorsal
slope is evenly curved. The shell surface
is generally sculptured with low, wide,
concentric ridges. Mature individuals
may reach a length of 130 mm. Shells of
the medium-sized to small river forms,
Fusconaia subrotunda kirtlandiana are
more compressed and Ortmann (1919)
noted that the two forms graded into one
another and the separation was artificial.
The left valve has two low, heavy
triangular pseudocardinal teeth, widely
separated with deep striations; the two
lateral teeth are moderately long and
straight. The right valve has a heavy,
triangular serrated pseudocardinal tooth
usually with a low tooth or roughened
area on either side. The lateral tooth is
broad, serrated, and often doubled for
most of its length. Muscle scars are
deeply impressed, the interdentum is usually wide, and the beak cavity is deep and somewhat compressed. The periostracum is a dull straw yellow to greenish brown, becoming blackish in old individuals. Some may show subtle green rays, primarily on the umbos. The nacre is pearly white and iridescent posteriorly (Parmalee and Bogan 1998:120-121). Life History and Ecology: The small to medium-sized river forms of Fusconaia subrotunda typically are found in currents, usually in riffle areas, at a depth of less than two feet. The big river form, such as specimens formerly inhabiting the Ohio, Allegheny and Monongahela rivers lived at depth, in strong current, and on a gravel substrate. The more compressed small river form was widespread living in gravel and sand substrates with good current (Ortmann, 1919). The Longsolid, like other species of Fusconaia for which the breeding season is known, is probably tachytictic, the females becoming gravid during the summer. Host fish for the glochidia is unknown. Status: Special Concern (Williams et al., 1993:11). Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina
Lampsilis cariosa (Say, 1817) Yellow Lampmussel
Plate 5, Figure 25
Synonymy: Unio cariosus Say, 1817; Say, 1817:no pagination, pl. 3, fig. 2 Unio crocatus Lea, 1841; Lea, 1841:31
Type Locality: Delaware and Schuylkill
rivers; [Susquehanna River] Wilkes
Barre; [Luzerne County; all
Pennsylvania] Johnson (1947) restricted
the type locality to Schuylkill river, near
Philadelphia, Pennsylvania.
General Distribution: The Yellow
Lampmussel extends from the Ogeechee
River Basin, Georgia, north to Nova
Scotia and Cape Breton Island, and
westward in the St. Lawrence River
Basin to the lower Ottawa River
drainage and the Madawaska River
(Johnson, 1970).
North Carolina Distribution: This
species is known from the Pee Dee,
Waccamaw, Cape Fear, Neuse, and
Pamlico basins (Johnson, 1970; Table
2).
Description: Shell shape is obovate,
shell thickness begins as thin in juveniles
becoming thicker with age, moderately
inflated, shell length 120 mm. Anterior
margin is rounded, ventral margin
slightly curved, posterior margin bluntly
rounded. Male shells elliptical and
somewhat elongate in outline with the
ventral margin evenly convex. Female
shells are subovate to obovate in outline
with the ventral margin expanded near
the posterior margin, sloping up to a
very bluntly rounded posterior margin.
Posterior ridge is poorly developed and
rounded, posterior slope slightly convex
to flat. Beaks moderately swollen but
not elevated much above the hingeline,
located anterior of the middle of the
shell, beak sculpture consist of about
five poorly defined bars, the first ridge
concentric with the remainder slightly double-looped. Periostracum is waxy and shiny. Left valve with two compressed pseudocardinal teeth, the posterior tooth low and immediately under the umbo, two delicate lateral teeth. Right valve has a single compressed pseudocardinal tooth, and a single lamellar lateral tooth. The pseudocardinal teeth tend to become more stumpy and ragged with age. Interdentum is practically absent, the beak cavity is open and moderately deep. Periostracum is waxy yellow, often with a trace of green in it, rays are either absent or restricted to the posterior slope or slightly in front of it. The rays are variable in width, but usually thin, sharp and dark green to black, contrasting with the yellow of the background. Older specimens become brownish and loose much of the luster. Nacre color bluish-white, often tinged with cream or salmon. Life History and Ecology: Ortmann (1919) observed that gravid females were seen in August, with glochidia appearing only in late August. The species is bradytictic, releasing glochidia in the following spring or early summer. The Yellow Lampmussel is found in medium to larger rivers often in sand in bedrock cracks, but also is found in silt, sand, gravel, and cobble substrates. Wick and Huryn (2002) have identified the Yello Perch (Perca flavescens) and the White Perch (Morone americana) as host fish for the Yellow Lampmussel in Maine. Status: Threatened (Williams et al., 1993:12). This species is listed as State Endangered, effective July 1, 2002. Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina
Lampsilis fasciola
Rafinesque, 1820 Wavyrayed Lampmussel
Plate 5, Figure 26
Synonymy: Lampsilis fasciola Rafinesque, 1820; Rafinesque, 1820:299
Type Locality: Kentucky River.
General Distribution: “Great Lakes
drainage in the tributaries of lake
Michigan, Lake Huron, Lake St. Clair
and Lake Erie, and Ohio–Mississippi
drainage south to the Tennessee River
system” (Clarke, 1981a).
North Carolina Distribution: The
Wavyrayed Lampmussel occurs in a
large number of medium-sized rivers
including the Hiwassee, Little
Tennessee, Pigeon, and French Broad
rivers (Ortmann, 1918, Table 3).
Description: The shell is elliptical or
subovate, fairly thin to solid and heavy;
it is generally inflated, especially so as a
marsupial swelling in some females.
Mature individuals may reach a length of
90–100 mm. The anterior end is broadly
rounded; the ventral margin is straight to
slightly curved; the posterior end is
rounded (in some females) to bluntly
pointed (in males). The posterior ridge is
broadly rounded; the posterior-dorsal
margin is occasionally compressed,
appearing alate. Beaks are full,
depressed, and only slightly elevated
above the hinge line; sculpture consists
of several indistinct, fine, wavy ridges.
The surface is shiny, usually with
numerous raised rest lines.
The left valve has two triangular,
short, thick, rather widely separated
pseudocardinal teeth; the two lateral
teeth are short, thick, nearly straight, and
widely separated. The right valve has a
large, coarsely serrated, heavy, erect
pseudocardinal tooth, sometimes with a
suggestion of a smaller tooth on either side as slightly roughened, raised areas; the lateral tooth is wide, short, and elevated. The interdentum is narrow or absent; the beak cavity is wide and moderately deep. The periostracum is light yellow or yellowish green, the beaks often tinged with reddish brown; the surface is densely patterned with green rays of varying widths, characteristically wavy in appearance, and often interrupted at the lines of growth. The nacre is white or bluish-white as a result of iridescence, especially posteriorly (Parmalee and Bogan, 1998). Life History and Ecology: Lampsilis fasciola is a species typical of small to medium-sized rivers, usually occurring at depths of three feet or less. This mussel appears tolerant of habitat conditions unfavorable to many species, and, under favorable circumstances, including moderate current and a stable substrate composed of mud, sand, and gravel, it may become quite abundant locally. In spite of the extensive range and local abundance of the Wavyrayed Lampmussel, its reproductive period remains unknown, although there is some evidence to suggest it is bradytictic. In their detailed study of fish hosts of four species of Lampsiline mussels, Zale and Neves (1982a) found that glochidia of Lampsilis fasciola parasitized only Smallmouth Bass (Micropterus dolomieu). Brian Watson, in experimenting with potential fish hosts for the glochidia of this mussel, was able to get glochidia to parasitize and transform on Largemouth Bass (Micropterus salmoides) (S. A. Ahlstedt, pers. comm., 1996; Parmalee and Bogan, 1998). Status: Currently Stable (Williams et al., 1993:12). This species is listed as State Special Concern. Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina
Lampsilis fullerkati Johnson, 1984 Waccamaw Fatmucket
Plate 5, Figure 27
Synonymy:
Lampsilis fullerkati Johnson, 1984; Johnson, 1984:305-319 Type Locality: Lake Waccamaw, North Carolina. General Distribution: Restricted to the Waccamaw basin in North Carolina and South Carolina (Johnson, 1984).
North Carolina Distribution:
Restricted to the Waccamaw basin (Johnson, 1984). Description: "Shell small, seldom exceeding 60 mm in length. Outline elongated rhomboidal to long elliptical. Valves subinflated, thin, inequilateral. Anterior end regularly rounded; posterior end slightly biangulate and pointed toward the base in the male; female broadly rounded and somewhat expanded in the postbasal region. Ventral margin straight, slightly curved, or occasionally arcuate roughly parallel to the almost straight dorsal margin, which forms an angle with, or merges imperceptibly with the obliquely descending margin. Posterior ridge high somewhat angular, usually with a faint second ridge above it ending behind in a broad point in the male. Umbos rather sharp but not full or high, located in the anterior quarter of the shell, their sculpture not observed. Periostracum rather smooth with delicate growth lines, generally yellowish or brownish green, with rather fine dark greenish rays of varying width often visible over the entire surface. Left valve with two stumpy pseudocardinal teeth, one in front of the other, often of almost equal height. Hinge line short and narrow, two short almost straight lateral teeth. Right valve with one triangular pseudocardinal, and a vestigial one before it; one lateral tooth. Beak cavities very shallow, with a few dorsal muscle scars. Anterior and posterior adductor muscle scars and pallial line distinct. Nacre purplish often lurid and spotted, somewhat iridescent." (Johnson, 1984). The rays and lessened sharp angular ridge on the posterior shell slope of L. fullerkati help separate it from E. waccamawensis (the latter generally is without rays on its posterior surface). Life History: Glochidia have valves that are bilaterally symmetrical, hookless and purse shaped. There are eyespots near the ventral border. The hinge line is straight with the umbos extending slightly above the hinge line giving this line sometimes a false convex appearance. Dimensions, as reported in Porter and Horn (1980) (under Lampsilis sp.) are: length = 0.222 mm; height = 0.276 mm; hinge length = 0.120 mm; hinge length/length ratio = 0.76; height/length ratio = 1.24; and hinge length/height ratio = 0.44. Average habitat depth for this naiad was 2.07 m with a range of 0.4-3.5 m This species is a typical lampsilid bradytictic (slow term or winter) breeder (Porter, 1985, Porter and Horn, 1983). Evidence of breeding condition (female gills containing a swollen marsupia) by this lampsilid were observed in Lake Waccamaw waters during the 1979-1981 investigative period (Porter, 1985): April, June 1979; March, June, September, December 1980. Status: Williams et al. (1993:12) listed as threatened. This species is listed as State Threatened in North Carolina. Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina
Lampsilis radiata radiata
(Gmelin, 1791) Eastern Lampmussel Lampsilis radiata conspicua (Lea, 1874) Carolina Fatmucket
Plate 5, Figure 28
Synonymy: Mya radiata Gmelin, 1791; Gmelin, 1791:3220 Unio conspicuus Lea, 1872; Lea, 1872:156
Type Locality: Ortmann (1919:296)
reported the locality of Malabar listed by
Gmelin (1791) as incorrect and noted
Lamarck (1819) had listed it from
Saratoga Lake in New York and
recommended “if there should not be
any other earlier record, we might select
this as the type locality.” Simpson
(1914) listed Virginia as the type
locality. Johnson (1970) restricted the
type locality to Potomac River, District
of Columbia (approximately opposite,
Farifax Co., Virginia). We use the
Saratoga Lake, NewYork as the type
locality.
General Distribution: The Eastern
Lampmussel occurs discontinuously
north from the Pee Dee River of South
Carolina to the St. Lawrence River
Basin, extending west to Lake Ontario.
North Carolina Distribution: The
Eastern Lampmussel is found in the Pee
Dee, Waccamaw, Cape Fear, Neuse, and
Pamlico basins (Johnson, 1970, Keferl
and Shelley, 1988; Table 2). The
Carolina Fatmucket is found in the
headwaters of the Yadkin-Pee Dee and
Neuse river basins in North Carolina
(Table 2).
Description: Shell shape is subelliptical
to subovate in outline, shell valves are
thick and solid, shell valves vary from
hardly inflated to quite inflated, shell
length is 93 mm. Anterior end rounded,
ventral margin straight to gently curved,
posterior margin rounded. Male shells elongate and not expanded posteriorly, while female shells are expanded in the postbasal area, but the amount of swelling is variable and some females are difficult to distinguish from male shells. Posterior ridge low to absent, the posterior slope is broad. Beaks are rather sharp but are not full or very high, beak sculpture consists of delicate, doubly looped sculpture, periostracum roughed by close concentric wrinkles. Left valve has two pseudocardinal teeth, the posterior one located under the beak, and two straight lateral teeth. The right valve has two separate pseudocardinal teeth, the upper is smaller and compressed, and has a single straight lateral tooth. Interdentum is lacking, beak cavity is shallow, compressed. Periostracum is yellowish or brownish green with dark green or black rays over the entire surface, rays are not well defined. Nacre color is white, may be tinged with pink or salmon or may be completely pink or salmon. Life History and Ecology: Ortmann (1919) reported gravid females with eggs on 22 August and gravid females with glochidia on 20 August. He seemed to think the species is bradytictic, possibly with overlapping ends to the breeding season. Ortmann (1919) reported the Eastern Lampmussel from the Delaware River in fast current in gravel substrate and in a sandy substrate in the lake like portion of the lower Delaware River. Strayer and Jirka (1997:60) recorded this species from creeks, lakes and rivers. The authors have found the Eastern Lampmussel in sand substrate with good current. The Black Crappie, (Pomoxis nigromaculatus) Largemouth Bass (Micropterus salmoides), Pumpkinseed (Lepomis gibbosus), Rock bass (Ambloplites rupestris), Smallmouth Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina
Bass (Micropterus dolomieu), and Yellow Perch (Perca flavescens) have been identified as hostfish for the glochidia of this mussel (Watters, 1994; Tedla and Fernando, 1969). Status: Currently Stable (Williams et al., 1993:12). Both the Eastern Lampmussel and the Carolina Fatmucket are listed as State Threatened, effective July 1, 2002. Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina
Lasmigona decorata (Lea, 1852) Carolina Heelsplitter
Plate 5, Figure 29
Synonymy: Unio decoratus Lea, 1852; Lea, 1852:257, pl. 13, fig. 6
Type Locality: Abbeville District,
South Carolina
General Distribution: Historically the
Carolina Heelsplitter was recorded from
the Abbeville District in South Carolina,
and around Mecklenburg County in
North Carolina (Clarke, 1985). Johnson
(1970) assumed that the records from the
Abbeville District, South Carolina were
in the Savannah River system. However,
it is more likely that the Carolina
Heelsplitter was in the Saluda River
drainage instead (Clarke, 1985, Keferl
and Shelley, 1988) (Adams et al., 1990).
North Carolina Distribution: Keferl
and Shelley (1988) did not find any
evidence of L. decorata in the Saluda
River drainage. Keferl and Shelley
(1988) did find the species living in
Waxhaw Creek (Catawba River drainage)
Union County, North Carolina; Goose
Creek (Pee Dee River system), Union
County, North Carolina; and Lynches
River (Pee Dee River system), Lancaster
and Chesterfield counties, South
Carolina. At the present time living
specimens of the Carolina Heelsplitter
have been found from just six localities in
three different drainages of three different
river systems.
Description: The Carolina Heelsplitter
can reach a length of 118 mm, with a
height of 68 mm and a width of 39 mm.
Based on some specimens collected by
Keferl and Shelley (1988) from three
different streams and rivers, the mean
length is 78 mm, the mean height is 43
mm and the mean width is 27 mm. The
shell is an ovate trapezoid. The dorsal
margin is straight and may end with a
slight wing. The umbo is flattened. The beaks are depressed and project a little above the hinge line. The beak sculpture is double looped. The unsculptured shell can have a yellowish, greenish or brownish periostracum. The Carolina Heelsplitter can have greenish or blackish rays. The lateral teeth may or may not be well developed, in most cases they are thin. The pseudocardinal teeth are lamellar and parallel to the dorsal margin, and there is a slight interdentum. The nacre varies from an iridescent white to a mottled pale orange. (Adams et al., 1990). Life History: Historically the Carolina Heelsplitter was collected in creeks, streams, a river and ponds. The ponds were probably millponds. Keferl and Shelley (1988) found L. decorata living in two small streams and one small river. All specimens found were in shaded areas, either in a ponded portion of a small stream, or in runs along steep banks with a moderate current. All specimens were found in less than three feet of water during low waters of summer and fall. The substrates included soft mud, sand, muddy-sand, and sandy gravel. Almost nothing is known about the life history and ecology of Lasmigona decorata. Living specimens of L. decorata have been collected in late June, August and late October and none had any glochidia. The fish host(s) has not been determined. (Adams et al., 1990). Status: Williams et al. (1993:13) listed as endangered. This species is federally and state listed as Endangered. The U.S. Fish and Wildlife Service (1997) has developed a recovery plan for this species. The U.S. Fish and Wildlife Service (2002) has designated critical habitat for the Carolina Heelsplitter. Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina
Lasmigona holstonia (Lea, 1838) Tennessee Heelsplitter
Plate 5, Figure 30
Synonymy: Margaritana holstonia Lea, 1838; Lea, 1838b:42, pl. 13, fig. 37
Type Locality: Holston River.
General Distribution: Upper Tennessee
River drainage; headwaters of the Coosa
River (Simpson, 1914).
North Carolina Distribution: This
species is known from Valley Creek,
Cherokee County, North Carolina,
Hiwassee River basin (Clarke, 1985),
Mills River, French Broad River basin
(T. Savidge, Pers. Comm. March 2002),
and Iotla Creek, Little Tennessee River
basin (W. McLaren, Pers. Comm. 4 July
2002).
Description: The shell is somewhat
elongated, rhomboid, and moderately
inflated; some very young juveniles are
more oblong and compressed. Beaks are
full but not high, projecting only slightly
above the hinge line; sculpture consists
of 4–5 strong, double-looped ridges; the
last loop is low and almost straight. The
anterior margin is broadly rounded,
while the ventral margin is straight; the
posterior end is broadly pointed to
squared; the posterior ridge is
pronounced but broadly rounded, in
some specimens appearing doubled. The
shell is thin but not fragile. Mature
specimens seldom exceed 75 mm in
length. The surface is roughened with
irregular, recessed, darkened rest lines.
The right valve has a single compressed,
but moderately heavy, pseudocardinal
tooth; the left valve has two low,
compressed pseudocardinal teeth, angled
anteriorly and, in both valves, nearly
parallel with the hinge line. Lateral teeth
appear as a thickening of the hinge line
in each valve. The periostracum is an
almost uniform dull greenish brown or
yellowish brown, and most shells become a dark brown or black with age. The nacre is bluish white, often with a pale salmon wash in the beak cavity area. (Parmalee and Bogan, 1998). Life History and Ecology: Lasmigona holstonia is a species most often found inhabiting small shallow streams and headwater creeks with some current, and it may become locally abundant in stretches of substrate composed of sand and mud. The reproductive period is unknown, but it is probably bradytictic. Steg and Neves (1997) identified the Banded Sculpin (Cottus carolinae) and the Rock Bass (Ambloplites rupestris) with the possible additional hosts are Central Stone Roller (Campostoma anomalum), Striped Shiner (Luxilus chrysocephalus) and Warpaint Shiner (Luxilus cocogenis) as host fish for the glochidia of the Tennessee Heelsplitter. Status: Special Concern (Williams et al., 1993:13). This species is listed as State Endangered. Bogan, 2002, Workbook and Key to the Freshwater Bivalves of North Carolina
Lasmigona subviridis
(Conrad, 1835) Green Floater
Plate 6, Figure 31
Synonymy: Unio subviridis Conrad, 1835; Conrad, 1835a:4 (appendix), pl. 9, fig. 1
Type Locality: Schuylkill River, Juniata
River, c