University of - Lincoln DigitalCommons@University of Nebraska - Lincoln

Transactions of the Nebraska Academy of Sciences and Affiliated Societies Nebraska Academy of Sciences

11-2011

The Freshwater Mussels (: : Unionoida) of Nebraska

Ellet Hoke Midwest Malacology, Inc., [email protected]

Follow this and additional works at: https://digitalcommons.unl.edu/tnas

Part of the Life Sciences Commons

Hoke, Ellet, "The Freshwater Mussels (Mollusca: Bivalvia: Unionoida) of Nebraska" (2011). Transactions of the Nebraska Academy of Sciences and Affiliated Societies. 2. https://digitalcommons.unl.edu/tnas/2

This Article is brought to you for free and open access by the Nebraska Academy of Sciences at DigitalCommons@University of Nebraska - Lincoln. It has been accepted for inclusion in Transactions of the Nebraska Academy of Sciences and Affiliated Societiesy b an authorized administrator of DigitalCommons@University of Nebraska - Lincoln.

The Freshwater Mussels (Mollusca: Bivalvia: Unionoida) Of Nebraska

Ellet Hoke Midwest Malacology, Inc. Correspondence: Ellet Hoke, 1878 Ridgeview Circle Drive, Manchester, MO 63021 [email protected] 636-391-9459 This paper reports the results of the first statewide survey of the freshwater mussels of Nebraska. Survey goals were: (1) to document current distributions through collection of recent shells; (2) to document former distributions through collection of relict shells and examination of museum collections; (3) to identify changes in distribution; (4) to identify the primary natural and anthropomorphic factors impacting unionids; and (5) to develop a model to explain the documented distributions. The survey confirmed 30 unionid and the exotic Corbicula fluminea for the state, and museum vouchers documented one additional unionid species. Analysis of museum records and an extensive literature search coupled with research in adjacent states identified 13 additional unionid species with known distributions near the Nebraska border. Some of these unionids may have formerly inhabited the state. Seven documented species have probably been extirpated, and the ranges of 15 others have contracted significantly. Only nine species are relatively stable at present, and one of these is extremely rare and feder- ally endangered. Diversity is concentrated in the formerly glaciated portion of eastern Nebraska, and drops abruptly along the River to the east and in the westward. The primary natural factors influencing unionid distributions in Nebraska include availability of perennially flowing waters, host fish diversity, substrate composition and stability, and formerly heavy sediment loads. Anthropomorphic factors are surface and subsurface irrigation withdrawals, construction of canals and reservoirs, channelization, erosion, intensive grazing, contaminants, and the introduction of invasive species. Unionid presence and diversity largely correlates with substrate stability. Stream orientation and morphology in portions of eastern Nebraska promote slow currents, and substrates composed of mud, sand, and rock provide greater stability than the shifting sand substrates common elsewhere in the state. In central and Nebraska, unionid populations are concen- trated in headwaters, backwaters, and side-channels of rivers, and canals, reservoirs, and small tributaries, while the generally shifting sand of most rivers provide relatively little viable . In the historic , unstable substrates and (formerly) heavy sediment loads limited diversity to silt tolerant species, and viable habitat largely to backwaters, sloughs, attached lakes, side channels, and relatively few main channel environments. Today, upstream dams have greatly reduced the sediment load in the Missouri River, but unstable substrates restrict mussels to backwaters, side channels, pools below wing dams, revetments, and other areas sheltered from strong currents. Channelization and erosion/sedimentation have destroyed or drastically impacted stream habitats in eastern Nebraska resulting in the loss of much of the original unionid diversity. Surface and subsurface irrigation coupled with related declines in water tables have eliminated habitat in western Nebraska, though losses are partially compensated for some species by colonization of viable reaches of newly created impoundments and canals. Intensive grazing along streams and agricultural pollution further exacerbate habitat deg- radation and pressure remaining unionid populations. Invasive species directly compete with native mussels for sustenance and living space and may become serious threats to the survival of remaining unionid species in some habitats.

Introduction The greatest unionoid diversity in the world is in Research on Nebraska mussels did not benefit (Bogan, 1993). The eastern, midwestern directly from the flow of money into the field in the and southern contain the greatest early 1900’s propelled by commercial interest in diversity and populations of mussels, and are also the mussels relating to the button industry. In 1900 there regions that have received the majority of attention, was one button manufacturer in Nebraska and two scientific and otherwise. Investigations in the Missouri by 1905 (Wilson, 1910), however, Coker (1919) does River Basin from the River northward were not include Nebraska in his list of states where “the minimal until the last quarter of the twentieth century. mussel fishery is pursued more or less actively.” In Nebraska during the nineteenth and most of the The extent of research in adjacent states at the twentieth centuries, research on mussels was largely initiation of this study was similarly limited. In limited to reports of their existence (William Clarke - Kansas, Murray and Leonard (1962) listed only a few 1804 as cited in Moulton, 2003), a few isolated species occurring north of the Kansas River. The latest collections (Lea, 1858; Hayden, 1862; Tryon, 1868; research in Missouri was that of Utterback (1914, 1915- Walker, 1906; Canfield and Wiebe, 1931), and a small 16, 1917), and in , the most recent number of museum vouchers often with only general publication was that of Over (1942). Little was known locational data (i.e. state, river). The most extensive of the mussels of western (Keyes, 1888; Bovbjerg publication on the unionoids of Nebraska was that of et al. 1970), and the Missouri River was reported to be Aughey (1877), however, aspersions on his academic devoid of molluscan life below the confluence of the reputation as well as questions on the accuracy of his Milk River in eastern Montana (Hayden, 1862; identifications preclude reliance on that paper (Bolick, Utterback, 1914, 1915-1916, 1917; Coker and Southall, 1993; Hoke, 2000b). 1915; Over, 1915, 1942; Bartsch, 1916).

2011 Transactions of the Nebraska Academy of Sciences 32, 1–46 1 E. Hoke The general absence of research on Nebraska The unionoid reproductive cycle is susceptible to unionids in 1972 suggested the need for a statewide interruption at many points. For example, elimination survey, and this study was initiated at that time. The of the host fish will, over time, result in the elimination goals of the study were: (1) to document existing of dependent species of freshwater mussels. Similarly, distributions through a statewide survey of living displacement of the host fish from the immediate and recent shell materials; (2) to document the extent vicinity of female mussels during the breeding period of past distributions through collection of relict can produce the same effect. Different species of specimens and by searching museums for relevant mussels have evolved a number of methods to achieve vouchers; (3) to identify changes in the fauna through infection of host fish. There are two distinct levels to comparison of distributions revealed by recent and this problem: (1) attraction of a suitable host fish to the relict shells; (4) to identify and understand the immediate vicinity of the female mussel, and (2) primary factors influencing past and present successful infection of the host with glochidia. Some distributions; and (5) to develop a model to account mussels solve both problems by one method: for changes in the fauna through time. broadcast dispersal of thousands of glochidia into the Before discussing the survey, it is necessary to water column. Many unionoid species produce briefly comment on the subjects of unionoid biology, conglutinates, worm-like structures filled with and the physical and aquatic geography of Nebraska. glochidia, that resemble one of the foods in the host A basic familiarity with these subjects is useful to fish’s diet. In eating the conglutinate, the fish becomes fully understand the sections that follow. infected with glochidia. Some fish species utilize thin- shelled mussels for food, and in the process of Unionoid Biology and Life History obtaining nourishment, may be infected with Freshwater mussels are the most imperiled faunal glochidia. There are many other strategies to attract group in North America (Williams et al. 1992) with and infect host fish including lures (Kraemer, 1970), 213 of the 297 known taxa considered to be extinct, mucus nets (Watters and O’Dee, 1997), and assembly endangered, threatened or of special concern. The of a glochidia filled structure, a superconglutinate, current condition of the fauna reflects the extent of resembling a fish used by the host as a primary food habitat deterioration, impediments to reproductive source (Haag et al. 1995). For more detailed cycles, and the introduction of invasive species that information, the reader is referred to Coker et al. (1921) compete for food and space. and Howells et al. (1996). Mussels embed themselves in the substrates of streams and lakes and filter the water for sustenance. Physical and Aquatic Geography of Nebraska Freshwater mussels use gills for respiration. Unionoids Nebraska encompasses an area of about 200,356 km2, are best adapted to flowing waters and most species do extending about 695 km east to west, and at its not thrive in lentic habitats such as lakes and ponds. maximum 354 km north to south (Fig. 1). Nebraska is Most species breed only during a relatively limited the sixteenth largest state in geographical extent, and period of the year, and most have separate sexes (e.g. the only state that lies entirely within the confines of are dioecious). A few species are hermaphroditic, or the Missouri River Basin. The surface rises gently occasionally hermaphroditic (van der Schalie and Lock, from 256 meters above sea level in southeastern 1940; van der Schalie, 1966, 1970). Unionoids have a Nebraska to 1,653 meters in the northwest. Rainfall complex reproductive cycle that begins with fertiliza- and humidity are greatest in the southeast and tion of eggs in females by sperm injected into the water decline to the northwest. Climate is temperate in the by upstream males and entering females with incurrent east and semiarid in the west. water. The fertilized eggs develop into the larval form The surface area is contained within two major (glochidia) in a specialized part of the gills, the marsu- physiographic provinces, the Central Lowlands and pium. The next stage of the reproductive process the Great Plains (Fenneman, 1931). In Nebraska, the involves the mandatory infection of a species-specific Central Lowlands is entirely within a lower level host fish or salamander with the parasitic larvae. The physiographic region, the . This larvae attach to gills or fins of host fish or salamanders. is an eroded Pre-Illinoian glaciated surface covered The transformation of glochidia to juvenile mussel with up to 61 meters of windblown , and occurs largely during the parasitic period. After com- extends from the Missouri River inland for a pletion of the parasitic stage, the young mussels drop maximum of about 160 km. Drainage patterns in this from their host, and continue to mature on their own. region are heavily influenced by glaciation, and their They reach sexual maturity at ages from 1 to 8 years, orientation reflects their former function as melt- depending upon the species (Coker et al. 1921), and water drainage routes (Wayne, 1985; Aber, 1999). some may then continue to live for decades. The division between the two provinces is shown in

2 2011 Transactions of the Nebraska Academy of Sciences 32, 1–46 Freshwater Mussels of Nebraska

Figure 1. Geographical Features of Nebraska

Figure 1. The Great Plains is unglaciated and includes Dissected Till Plains; Great Plains; and the Missouri all areas west of the Dissected Till Plains. A unique River and floodplain. The two former zones are as area within the Great Plains, the Sand Hills, consists described by Fenneman (1931) above except for the of windblown sand dunes covered by a light exclusion of the Missouri River and floodplain. In vegetation of grasses, and encompasses 62,000 km2 in this paper, the term “eastern Nebraska” refers to the northwest and north central Nebraska. In northwest region including both the Dissected Till Plains and Nebraska the Escarpment separates the the Missouri River and floodplain, and “western White River and Hat Creek drainages from the rest of Nebraska” is synonymous with the Great Plains. the state. Nebraska is primarily drained by the , Methods and its major tributaries, the Elkhorn, Loup, North The methods and equipment utilized in this survey Platte, and South Platte (Figure 2). Below the Platte, were strongly influenced by practical considerations. drainage is largely through tributaries of the Kansas Chief among these was the general absence of River: the Big Blue, and Little Blue rivers in the external financial aid or any on the ground support. southeast, and the Republican River in the west. In In this environment, a personal vehicle was utilized extreme southeastern Nebraska, the Big and Little rather than a four-wheel drive vehicle, and use of a Nemaha rivers flow directly into the Missouri River. boat was precluded. These factors in turn, limited North of the Platte tributaries (i.e. the Elkhorn and access in the sandy, unpaved roads in the Sand Hills, Loup rivers), the flows across and along the unchannelized and channelized northern Nebraska to the Missouri River, while the Missouri River respectively. The solitary nature of White River in northwest Nebraska flows into South the survey limited the personal risks I was willing to Dakota, and Hat Creek, a tributary of the Cheyenne take along the Missouri River as well. Logistical River, drains a small area in the extreme constraints due to the location of the author’s northwestern corner of the state. The Cheyenne and physical residence during much of the survey (i.e. White rivers ultimately flow into the Missouri River central Iowa 1981-1983 and St. Louis 1983-present), in central South Dakota. The Sand Hills region the extent of the survey area, and a field work season contains some 2,500 small, often alkaline lakes. In of only two or three weeks per year, precluded the much of this region, there is no true drainage system use of time consuming collection techniques such as and moisture is absorbed into the sandy soils scuba and snorkeling, the effort that could be (McCarraher, 1977). devoted to any one site, and largely dictated the In this paper, three aquatic/geographic provinces intervals between sites. Logistics also increased the are recognized as distinct unionid habitat zones: the time needed to complete the study.

2011 Transactions of the Nebraska Academy of Sciences 32, 1–46 3 E. Hoke

Figure 2. Nebraska Drainage Basins.

Initial work was conducted in 1972 as a part of the later expanded to include northern Kansas. An requirements of a graduate class in zoology and later attempt was made to sample essentially all the same year as a funded independent research freshwater habitats including: major and minor project. Based upon these initial efforts, the study rivers, creeks, canals, lakes, and reservoirs. Unless was expanded to encompass the entire state. In the otherwise noted, specimens at all sites were collected absence of previous studies and in an effort to obtain by or directly donated to the author. some general knowledge of the geographic extent of Sites were sampled by hand and with the use of a the unionid fauna of Nebraska, a questionnaire was garden rake, usually during periods of low water. mailed to Nebraska Game and Parks Commission Fresh dead specimens were collected in preference to conservation officers in 1976 requesting information live material, and few live specimens were retained. on the known location of mussel populations in the At least one specimen of each species at every site state. Responses received formed the basis for much was retained to document the fauna collected. Relict of the early collection effort, and indicated the specimens were actively collected to document existence of mussels in the Missouri River, thought to species not represented by live or recent be uninhabitable for mussels at the time (Hayden, shells at sampling locations, and with the hope of 1862; Utterback, 1914, 1915-1916, 1917; Coker and collecting species extirpated from the state. Southall, 1915; Over, 1915, 1942; Bartsch, 1916). To Most sites were collected upstream from road gain a general view of distributions in other upper access points, usually bridges. In some western Missouri Basin states, conservation officers in portions of the state, particularly the Sand Hills , Iowa, Montana, South Dakota, and region, limited road access and a general were queried by mail in 1978, and the unwillingness to grant access for collection, severely responses provided valuable insight on regional restricted sampling activities. Sites were recorded on unionoid distributions. USGS maps (scale 1:250,000). Field notes were The study was qualitative in nature, and no recorded at each site noting date, site number, time of attempt was made to obtain quantitative data. Sites day, relative productivity, and observations relevant were generally collected at intervals of 16 to 32 km, to the presence or absence of unionids. A though this goal was not possible to achieve in photographic record was also produced at most northwestern Nebraska due to access problems. In locales. Sites were collected until diversity plateaued some areas, intervals were contracted when collecting or the accessible area had been investigated. conditions were exceptional or the possibility of Specimens were placed in plastic bags by site as recovering formerly occurring species seemed likely. collected with an accompanying site number, and The scope of the work was initially statewide, and later cleaned, identified, and recorded by species on

4 2011 Transactions of the Nebraska Academy of Sciences 32, 1–46 Freshwater Mussels of Nebraska site inventory sheets. All specimens were then represented among the vouchers obtained in this wrapped in soft paper, repackaged in clean sacks study. To identify species that may have formerly with a site number for each bag, and stored in labeled occurred, an extensive literature search of early and boxes until specimens could be deposited in research recent publications from surrounding states was museums. conducted. These sources are: for Colorado, Cockerell Initially, all identifications were confirmed by (1889), Ellis (1916), Henderson ( 1920, 1924), either Dr. Harold Murray, then of Trinity University, Brandauer and Wu (1978), and Cordeiro (1999); for or Dr. David H. Stansbery, The State University Kansas, Call (1885a-c, 1886, 1887), Popenoe (1885), Museum of Biological Diversity. Subsequently, only Scammon (1906), Murray and Leonard (1962). Miller unusual specimens were confirmed. At least one and Hibbard (1972), Liechti and Huggins (1977), specimen of every species recovered in the survey was Schuster and DuBois (1979), Bleam et al. (1998), identified or confirmed by The Ohio State University Angelo et al. (2009); for Iowa, Keyes (1888), Bovbjerg Museum of Biological Diversity. The et al. (1970), Rausch and Bovbjerg (1973), Frest (1987), employed in this study follows Turgeon et al. (1998). Arbuckle et al. (2000); for Missouri, Utterback (1914, Vouchers for sites collected prior to 1991 have 1915-1916, 1917), Oesch (1995); for South Dakota, been deposited at The Ohio State University Museum Coker and Southall (1915), Over (1915, 1928, 1942), of Biological Diversity, Columbus, Ohio. Most Henderson (1927), Skadsen (1998), Backlund (2000), specimens collected after 1990 are currently in the Perkins and Backlund (2000, 2003), Shearer et al. possession of the author. Some post 1990 specimens (2005); and for Wyoming, Henderson (1924), Beetle have been deposited at the University of Michigan (1989), Cvancara (2005), Edwards (2010). References Museum of Zoology, Ann Arbor, Michigan and for other states in the Missouri River Basin arrangements have been made for others to be northward from Nebraska were examined including deposited at the National Museum of Natural , Sietman (2003); Montana, Henderson History, Washington, D. C. It is anticipated that all (1924, 1936), Gangloff and Gustafson (2000); and remaining vouchers will be donated to research , Cvancara (1975, 1983), Dyke (2000). museums within the next few years. Several general works on unionoid distributions were The relative dearth of information on the unionid consulted as well (Simpson, 1900; Burch, 1975; fauna of contiguous states, led to significant sampling Cummings and Mayer, 1992). in reaches of Nebraska rivers beyond the borders of Mussel shells are often recovered from the state. This effort was concentrated in northern archaeological sites in Nebraska and these may be Kansas, where the Republican, Little Blue, Big Blue, useful in documenting former ranges of the species and Big Nemaha rivers flow from or into Nebraska, represented. In this paper, it was decided to exclude and was further expanded to encompass most of the such data in plotting distributions due to the Kansas River Basin including the Smokey Hill, difficulty of associating archaeological shell materials Solomon, and Saline rivers (Hoke, 1996, 1997b, 2004, with a definite point of origin. Native American 2005b). Similarly, the Missouri River and floodplain bands often traveled great distances during the year. were first collected along the Nebraska border, and Thus, shells may have originated from the nearest subsequently, eastward and southward to its juncture stream, or from a stream many kilometers from the with the above St. Louis, Missouri locale of archaeological deposition. Further, it is (Hoke, 1983, 2005a, 2005c, 2009). A large portion of difficult to rule out the possibility shells were the impounded Missouri River was sampled: in obtained through trade. Archaeological specimens South Dakota - Lake Oahe (Hoke, 2003); North are often modified for use as tools or for Dakota - Lake Sakakawea; and Montana - Fort Peck ornamentation, and these were often traded. Unless Lake. Limited work was also conducted in streams in unmodified shell materials are found in quantity at Wyoming (Hoke, 1979), Montana, and eastern an archaeological site, it is speculative to assume Colorado. These regional collections were these originated nearby. supplemented with an extensive search of museum Results holdings at research institutions throughout the Survey activities were conducted in Nebraska United States. These facilities are given in a later between 1972 and 2000. This effort was section of this paper. During this process vouchers complimented by extensive collecting in northern relating to Aughey’s (1877) report on Nebraska Kansas (1983-2002) and scattered sampling in mollusks were located and evaluated (Hoke, 2000b). western Iowa, northwestern Missouri, eastern The general absence of reliable early research on Colorado, and Wyoming. Every river in Nebraska the streams of Nebraska, and their current condition was sampled as well as many perennial creeks and suggested that some former species might not be

2011 Transactions of the Nebraska Academy of Sciences 32, 1–46 5 E. Hoke canal systems, and a representative group of lentic clava. These species were first documented from the habitats. During the survey period, a number of Missouri River Basin in this study. Villosa lienosa was papers were published by others on mussels in confirmed for the state and the Missouri River Basin Nebraska, or along the Nebraska – South Dakota by a single nineteenth century museum voucher border (Baxa, 1981; Roedel, 1990; Lingle, 1992; collected by Hayden and first reported by Tryon Freeman and Perkins, 1992, 1997; Clausen and (1868). Mussels were recovered from the Missouri Havlik, 1994; Peyton and Maher, 1995; Perkins and River, where unionids were previously reported to be Backlund, 2000; Schainost, 2003; Shearer et al. 2005). absent, and the first survey of the channelized Much of the data from this study was published as a Missouri River was completed as well (Hoke, 1983, response to those publications; however, the goal of 2009). Collections at 276 locales in northern Kansas this survey was always to produce a statewide paper. documented one additional species for Kansas The survey resulted in the publication of eleven reaches of the Big Blue and Little Blue River. major papers (Hoke, 1983, 1994b, 1995, 1996, 1997b, fragosa (Conrad, 1835), a federally 2000b, 2004, 2005a, 2005b, 2005c, 2009); two reports to endangered species, was collected as relic valves state agencies (Hoke, 1979, 2003), and three minor publications (Hoke, 1994a; 1997a; 2000a). The Table 2. Unionid Species Collected or Documented for Nebraska portion of these papers and additional Nebraska unpublished material are presented in this paper. Current The survey of Nebraska unionids encompassed Formal Taxonomy Status1 sampling at 680 locales (Table 1). These included 392 productive locales (Fig. 3), and 288 non-productive locales (Fig. 4). The most consistently productive Ambleminae Amblema plicata (Say, 1817) D region was the Missouri River and its associated flava (Rafinesque, 1820) D oxbow lakes where 88.4% of all sites tested yielded Pleurobema clava (Lamarck, 1819) X, E live mussels or recent shell materials. The least Quadrula p. pustulosa (Lea, 1831) D productive drainages were the Niobrara (19.4%), Quadrula quadrula (Rafinesque, 1820) S Loup (34.3%) and South Platte (35.0%). Survey Tritogonia verrucosa (Rafinesque, 1820) D activities in northern Kansas included sampling at tetralasmus (Say, 1831) D 276 locales; most of these have been previously Anodontinae reported (Hoke, 1996, 1997b, 2004, 2005b, 2009). suborbiculata Say, 1831 S The study documented 31 unionid species for Anodontoides ferussacianus (Lea, 1834) D Nebraska (Table 2). Thirty species were recovered Arcidens confragosus (Say, 1829) D during the survey, including two federally c. complanata (Barnes, 1823) S endangered species, leptodon and Pleurobema Lasmigona compressa (Lea, 1829) X Pyganodon grandis (Say, 1829) S Table 1. Productivity of Nebraska Collection Sites by D Basin Strophitus undulatus (Say, 1817) imbecillis (Say, 1829) S Number (Percent) Lampsilinae X Basin Productive Not Productive Total Actinonaias ligamentina (Lamarck, 1819) cardium Rafinesque, 1820 D Big Blue 45 (73.8) 16 (26.2) 61 Lampsilis siliquoidea (Barnes, 1823) D Elkhorn 55 (54.5) 46 (45.5) 101 Lampsilis teres (Rafinesque, 1820) D Little Blue 12 (42.9) 16 (57.1) 28 (Rafinesque, 1820) S Loup 35 (34.3) 67 (65.7) 102 (Rafinesque, 1820) S, E Lower Platte 37 (84.1) 7 (15.9) 44 Ligumia recta (Lamarck, 1819) X Middle Platte 52 (69.3) 23 (30.7) 75 Ligumia subrostrata (Say, 1831) D Missouri 23 (88.5) 3 (11.5) 26 Obovaria olivaria (Rafinesque, 1820) X Missouri Tributaries 5 (50.0) 5 (50.0) 10 alatus (Say, 1817) D Nemaha 55 (82.1) 12 (17.9) 67 (Rafinesque, 1820) S Niobrara 7 (19.4) 29 (80.6) 36 Potamilus purpuratus (Lamarck, 1819) X North Platte 12 (66.7) 6 (33.3) 18 Toxolasma parvus (Barnes, 1823) S Republican 45 (51.7) 42 (48.3) 87 Truncilla donaciformis (Lea, 1828) D South Platte 7 (35.0) 13 (65.0) 20 Truncilla truncata Rafinesque, 1820 D White/Hat Creek 2 (40.0) 3 (60.0) 5 Villosa lienosa (Conrad, 1834) X Total Sites 392 (57.6) 288 (42.4) 680 1D = declining; E = endangered; S = stable; X = extirpated

6 2011 Transactions of the Nebraska Academy of Sciences 32, 1–46 Freshwater Mussels of Nebraska

Figure 3. Productive Survey Locales.

Figure 4. Non-Productive Survey Locales. from two sites below the Nebraska border (Hoke, The Nebraska portion of the study produced 1,068 1997a, 2004, 2005a). In addition, Lasmigona compressa, unionid species occurrences or species-specific previously unknown in Kansas, was collected from a geographic occurrences (Table 3), and four reach of the South Fork of the Big Nemaha River, and occurrences of the introduced bivalve Corbicula Anodonta suborbiculata last reported from northern fluminea (Muller, 1774). The occurrences documented Kansas by Scammon (1906) was recovered from for Nebraska in this study are plotted by species on Browning Lake on the Kansas-Missouri border in 32 maps (Figs. 5-36) and presented in Appendix 1. northeastern Kansas (Hoke, 1996, 2009). Occurrences shown along the Missouri River include

2011 Transactions of the Nebraska Academy of Sciences 32, 1–46 7 E. Hoke Table 3. Nebraska Unionid Species Occurrences Diversity at productive sites ranged from one to a maximum of 19 species, and averaged 2.72 species Species Number Percent per site. The most diverse site encountered was on Actinonaias ligamentina 2 0.19 Logan Creek in the Elkhorn Basin. Diversity was Amblema plicata 35 3.28 greatest in the Dissected Till Plains and abruptly Anodonta suborbiculata 4 0.37 declined in the Missouri River and floodplains to the Anodontoides ferussacianus 92 8.61 Arcidens confragosus 2 0.19 east and the Great Plains westward. Streams in the Fusconaia flava 42 3.93 Dissected Till Plains once supported populations of Lampsilis cardium 52 4.87 29 of the 31 species documented for Nebraska. The Lampsilis siliquoidea 35 3.28 Big Blue, Nemaha, and Elkhorn drainages yielded Lampsilis teres 25 2.34 from 20 to 28 species each. In contrast, this study and Lasmigona c. complanata 114 10.67 other recent research confirmed only 16 species for Lasmigona compressa 2 0.19 the Missouri River and floodplain adjacent to Leptodea fragilis 33 3.09 Nebraska, including two species (Anodonta Leptodea leptodon 1 0.09 suborbiculata and Leptodea leptodon) that appear to be Ligumia recta 16 1.50 restricted to that region (Hoke, 1983, 2009; Clarke, Ligumia subrostrata 23 2.15 1996; Backlund, 2000; Perkins and Backlund, 2000; Obovaria olivaria 4 0.37 Shearer et al. 2005; Duggan, 2009a). The Great Plains Pleurobema clava 1 0.09 supported 17 species, including one, , Potamilus alatus 11 1.03 that is probably recently introduced to the region, Potamilus ohiensis 60 5.62 and another, Strophitus undulatus, recovered in other Potamilus purpuratus 2 0.19 studies (Peyton and Maher, 1995; Freeman and Pyganodon grandis 193 18.07 Perkins, 1997). Northwestern portions of the Great Quadrula p. pustulosa 51 4.78 Plains were significantly less diverse with only five Quadrula quadrula 118 11.05 species, and no mussels were recovered from the Strophitus undulatus 30 2.81 lakes. Toxolasma parvus 11 1.03 The current condition of the Nebraska mussel Tritogonia verrucosa 11 1.03 fauna is poor, and largely reflects the extent of habitat Truncilla donaciformis 5 0.47 destruction in eastern Nebraska. Seven species Truncilla truncata 7 0.66 (Actinonaias ligamentina, Lasmigona compressa, Ligumia 65 6.09 recta, Obovaria olivaria, Pleurobema clava, Potamilus 21 1.97 purpuratus, and Villosa lienosa), 23% of the Nebraska Villosa lienosa1 – – fauna, were documented only by relict shells or early Total Occurrences 1,068 100.00 museum vouchers, and have probably been 1 Represented only by a museum voucher. extirpated from the state. Most of these species were collections on Iowa, Missouri, Nebraska, and South represented by only a handful of occurrences, Dakota shores. The maps include results from other perhaps indicating their former rarity. Pleurobema studies to the extent they enhance the distributions clava was documented by a single relict valve. In delineated in the current study. Sixty-five occurences contrast, L. recta was once relatively widespread in from other studies are included on these maps. Also the Dissected Till Plains. The mussel was also plotted, are the locales of 53 relevant museum formerly widespread in Kansas, but Angelo et al. vouchers. Data from non-survey sources utilized in (2009) found only one live specimen in their survey, species maps is given by figure in Appendix 2. and indicated the species “now lacks reproductively Survey occurrences were highly concentrated viable populations” in that state. among a relatively small number of species. The distributional ranges of fifteen extant species Anodontoides ferussacianus, Lasmigona c. complanata, have contracted, often significantly. Eleven species Pyganodon grandis, Quadrula quadrula, and Uniomerus largely restricted to the Dissected Till Plains in tetralasmus were the most frequently recovered eastern Nebraska have been heavily impacted. unionids and accounted for 582 occurrences, 54.5 Arcidens confragosus, Truncilla donaciformis and percent of all occurrences. The most widely Truncilla truncata, appear to be absent from Nebraska distributed unionid was P. grandis with 193 interior streams and are now present only in the occurrences, 18.1 percent of total occurrences. In Missouri River. Amblema plicata and Fusconaia flava contrast, the seventeen least common species may only survive in the Nebraska interior in upper included only 148 occurrences, 15 percent of study reaches of the Nemaha Basin. Tritogonia verrucosa occurrences. appears to be restricted to the lower Big Blue Basin 8 2011 Transactions of the Nebraska Academy of Sciences 32, 1–46 Freshwater Mussels of Nebraska (Schainost, 2003) and the Missouri River. Live siliquoidea were only collected from the Big Blue and populations of Potamilus alatus, formerly widely West Fork Big Blue rivers in this study, and fresh distributed in eastern Nebraska, are largely confined shells were also recovered from the unchannelized to the Missouri River, and possibly the upper Missouri River. The distribution of Uniomerus Nemaha Basin. A museum voucher of this species tetralasmus is declining due to a near absence of water from the Calamus Reservoir in the Loup Basin in portions of the upper Republican Basin, where the probably represents a recent colonization via westernmost populations were documented in this glochidia infected fish. Lampsilis teres may be absent study. from the Big Blue Basin, and live populations are The ranges of Anodonta suborbiculata, Lasmigona c. uncommon in its remaining range as well. Ligumia complanata, Leptodea fragilis, Leptodea leptodon, subrostrata is generally absent from the rivers and Potamilus ohiensis, Pyganodon grandis, Quadrula creeks of eastern Nebraska where relict shells quadrula, Toxolasma parvus, and Utterbackia imbecillis indicate it was formerly common. The sole fresh appear relatively stable at present. This conclusion is dead occurrence in this survey was from the based upon the recovery of live animals or fresh dead headwaters of the South Fork Big Nemaha River in shells throughout the ranges documented in this northeastern Kansas (Hoke, 1996). Additional study. Many of these unionids have been recovered, populations may persist in the upper Nemaha Basin sometimes in great numbers, from artificial lentic in Nebraska and in southeastern Nebraska farm habitats and or irrigation canals. The distributions of ponds. The latter habitats were not extensively P. grandis and U. imbecillis may have expanded with examined in this study due to the difficulty of the construction of ponds and reservoirs throughout obtaining access. Murray and Leonard (1962) the state. The most western locales for both species reported over 1,500 specimens of L. subrostrata from a were from such habitats. The distribution of A. drained one-acre lake on the University of Kansas suborbiculata is concentrated in oxbow lakes and other campus at Lawrence. Quadrula p. pustulosa, formerly slow current habitats along the Missouri River. Most common, has largely disappeared from the Nemaha of these environments have disappeared with and Little Blue basins as well as from most eastern channelization of the river. The sole Nebraska Nebraska creeks. In this survey live populations occurrence of L. leptodon and a second survey were concentrated in the Big Blue Basin, while occurrence in the Missouri River in eastern Missouri isolated individuals continue to survive throughout were as fresh shells. Though stable as defined above, the range documented in this study. Strophitus L. leptodon is exceedingly rare. undulatus was recovered only as relict shells in Three species reported for Nebraska either from eastern Nebraska and may now be absent in this published sources or represented by extant vouchers, region. Live specimens have been recovered from the have been excluded from the list of confirmed species Middle Platte and upper Niobrara Basins (Peyton due to questions on the reliability of the records upon and Maher, 1995; Freeman and Perkins, 1997). which their confirmation depends. Canfield and The ranges of four, more ubiquitous, unionid Wiebe (1931) reported the “butterfly mussel”, the species have also contracted significantly. Live common name for Ellipsaria lineolata (Rafinesque, populations of Anodontoides ferussacianus were largely 1820), from the Big Blue River at Crete, Nebraska limited to the Great Plains, though relict specimens during a fisheries survey of the river. Since E. were well distributed in the Dissected Till Plains. lineolata is quite distinctive and easily recognized and This unionid has also nearly disappeared from the Canfield had worked with people from the Fairport Republican Basin in Nebraska, where the species was Biological Station, a focus of research on freshwater represented by only a few scattered populations mussels in the early twentieth century, it is quite (Hoke, 1997b). The near absence of A. ferussacianus possible the report is valid. There are, however, no from eastern Nebraska may relate to generally turbid vouchers and acceptance of the report would extend stream conditions in that region. The presence of live the species known range rather significantly. The populations was associated with relatively clear nearest Missouri River tributary with this species is water, and the presence of only relict specimens was the Blackwater River in central Missouri (Oesch, generally associated with turbidity. Lampsilis cardium 1995), where the mussel was last collected by was recovered live or as a fresh shell from the Big Utterback (1915-1916). Lampsilis higginsii (Lea, 1857) Blue and Elkhorn basins. The only recent collection is represented by a voucher at the National Museum of fresh shells of L. cardium and Lampsilis siliquoidea of Natural History (No 512459) reportedly collected from the Little Blue River were specimens at the at West Point, Nebraska, and a single fresh valve University of Nebraska – Kearny Biology Department recently collected from the Missouri River below collected from one site in 1967. Live Lampsilis Gavins Point Dam on the Nebraska – South Dakota

2011 Transactions of the Nebraska Academy of Sciences 32, 1–46 9 E. Hoke

Figure 37. Distribution of Unionid Species Unvouchered But Reported for Nebraska by a Potentially Reliable Source, or Represented by Questionable Though Possibly Valid Museum Vouchers. Species indicated as follow: A = Alasmidonta marginata; E = Ellipsaria lineolata; and L = Lampsilis higginsii. border (Shearer et al. 2005). Though I have with Aughey’s 1877 paper, and may be valid, but I previously accepted the West Point record as am increasingly reluctant to place any reliance on evidence of the species in Nebraska (Hoke, 1994b), Aughey’s vouchers or report. Though I have greater familiarity with museum records and habitat previously accepted this record as valid (Hoke, 1996), discrepancies have led me to question this record. based upon research on Aughey (Hoke, 2000b) and Lampsilis higginsii is typically a big river species, and (again) more experience with museum records, I am its range is largely restricted to portions of the Upper uncertain one can rely on the veracity of this record, Mississippi River and the St. Croix River in and have accordingly classified this species as (Havlik, 1980). In contrast, West Point, unconfirmed for Nebraska. The locales reported for Nebraska is on the Elkhorn River, a small and the three species are plotted in Fig. 37. generally shallow river, near the eastern boundary of Review of the unionoid literature of the Missouri the Great Plains. The Missouri River specimen may River Basin combined with a search for vouchers at be a valid occurrence, and may represent a recent museum collections suggest as many as thirteen colonization. It is also possible the valve was additional species may once have been present in discarded by a visitor to the region, since it was eastern Nebraska (Table 4). Alasmidonta marginata, recovered from an area frequented by thousands of Cyclonaias tuberculata, dilatata, Lasmigona outdoor enthusiasts each year. Pending recovery of costata, Obliquaria reflexa, , additional specimens, this species should probably be Pleurobema sintoxia, Quadrula fragosa, and Quadrula considered a questionable component of the current metanevra are documented from the Missouri River Nebraska fauna. It is highly doubtful L. higginsii was Basin above the Platte River confluence with the present in the Missouri River before the closing of the Missouri in western Iowa and/or eastern South upper Missouri River dams after 1936. The river was Dakota. A former presence in eastern Nebraska simply too turbid and the substrates and channel too would be only a slight extension of documented unstable for the species. A third unionid, Alasmidonta historic ranges. Specimens of A. marginata, O. reflexa, marginata Say, 1820 is supported by a voucher at the P. sintoxia, and P. cyphyus, probably collected by University of Nebraska State Museum (No. 27-1-26- Aughey (1877), are in the collection at the University 87) with the location given “Nemaha” which could of Nebraska State Museum, though without reliable refer to either the Little Nemaha River near the town associated data, these cannot be confirmed for the of Nemaha, Nebraska or to an unspecified location on state. Relict specimens of Q. fragosa were recovered either the Little Nemaha or Big Nemaha rivers. The from both the Big Blue and Little Blue rivers at points specimen location and identification are congruent about 35 km below the Kansas-Nebraska border

10 2011 Transactions of the Nebraska Academy of Sciences 32, 1–46 Freshwater Mussels of Nebraska

Table 4. Unionid Species That May Have Occurred in Nebraska Based On Their Presence in Adjacent States

State NW Western South Species1 Kansas Missouri Iowa Dakota Locale2, 3 Alasmidonta marginata Say, 1818 – – – X aLittle Sioux River – – X – bBig Sioux River – – X – cBoyer River Cyclonaias tuberculata (Rafinesque, 1820) – – X – dBig Sioux River Elliptio dilatata (Rafinesque, 1820) X – – – eWakarusa River – – X – fBig Sioux River – – X – gBoyer River triquetra (Rafinesque, 1820) X – – – hWakarusa River Lasmigona costata (Rafinesque, 1820) – – X – iLittle Sioux River Megalonaias nervosa (Rafinesque, 1820) – X – – jPlatte River, Missouri Obliquaria reflexa (Rafinesque, 1820) X – – – kSmokey Hill River – – – X lBig Sioux River – – – X mJames River Plethobasus cyphyus (Rafinesque, 1820) – – X – nLittle Sioux River Pleurobema sintoxia (Rafinesque, 1820) X – – – oVermillion River – – X – pBoyer River – – X – qLittle Sioux River Ptychobranchus occidentalis (Conrad, 1836) X – – – rWakarusa River Quadrula fragosa (Conrad, 1835) X – – – sLittle Blue River X – – – tBig Blue River – – – X uJames River, SD Quadrula metanevra (Rafinesque, 1820) – – X – vPrairie Creek Simpsonaias ambigua (Say, 1825) – – X – wNishnabotna River

1Frest (1987) reported the collection of Fusconaia ozarkensis (Call, 1887) from the Boyer River in western Iowa. The species is otherwise known from only a small number of streams in southern Missouri, only one of which is a tributary of the Missouri River, and also from one site in southeastern Kansas on the Missouri border (Oesch, 1995; Angelo et al. 2009). Since (1) Arbuckle et al. (2000) collected the same sites and recovered no specimens of F. ozarkensis; and (2) all attempts to locate vouchers from Frest’s (1987) study have been unsuccessful, I have provisionally assumed the report of F. ozarkensis from the Boyer River is incorrect, and the species is accordingly excluded from this listing. 2Locales are plotted in Figure 38. 3Vouchers or literature references supporting these ranges are as follows: aUMMZ as given by Frest (1987); bSkadsen (1998); cFrest (1987); dNMNH – specimen given in Frest (1987); eScammon (1906); fNMNH as given by Frest (1987); gFrest (1987); hScammon (Murray and Leonard, 1962); iUMMZ Nos. 54804, 54843, 54846, 54862 and 7746 as given by Frest (1987); jUtterback (1917); kAngelo et al. (2009); lBacklund (2000); mPerkins and Backlund (2003); nUMMZ No. 233952; oUMMZ No. 153994 ; pFrest (1987); qNMNH Nos. 528696 and 535258 ; rCall (1885b); sHoke (2004); tHoke (2005b); u Perkins and Backlund (2003); vArbuckle et al. (2000); and wMCZ No. 564863 as given in Frest (1987). increasing the possibility of a former presence in the A large number of unionoid species were almost state (Hoke, 1997a, 2004, 2005b). This federally certainly reported erroneously for Nebraska by endangered species is now considered extirpated Aughey (1877). Appendix 3 lists the unionoids from Kansas (Angelo et al. 2009), though it appears to reported by Aughey with currently recognized have once been rather broadly distributed in eastern names and distributions as originally given. Many of Kansas (Bleam et al. 1998). An intensive collection these are highly improbable. At least one of effort focusing upon recovery of relict shells in the Aughey’s (1877) unsupported unionoids, Big Nemaha and Big Blue basins might succeed in Cumberlandia monodonta, has been included in the confirming at least some of these species for literature (Simpson, 1900; Walker, 1910; Burch, 1975) Nebraska. All these unionids are at the westward though usually with some skepticism. Given the limits of their ranges, and it is unlikely extant many questions concerning Aughey’s scholarship populations will be found in the decimated streams and unionoid identifications (Bolick, 1993; Hoke, of eastern Nebraska. The nearest documented 2000b) all information given by Aughey is suspect. occurrences of these species are illustrated in Fig. 38. Records probably collected by Aughey and utilized

2011 Transactions of the Nebraska Academy of Sciences 32, 1–46 11 E. Hoke

E G G

Figure 38. Unionid Species Not Reported for Nebraska But Considered Historically Possible on the Basis of Distributions in Adjacent States. Unionid species are indicated by capital letters as follows: A = Alasmidonta marginata; B = Cyclonaias tuberculata; C = Elliptio dilatata; D = Epioblasma triquetra; E = Lasmigona costata; F = Megalonaias nervosa; G = Obliquaria reflexa; H = Plethobasus cyphyus; I = Pleurobema sintoxia; J = Ptychobranchus occidentalis; K = Quadrula fragosa; L = Quadrula metanevra; and M = Simpsonaias ambigua. in this paper are only for species recovered in this however, in a series of papers on the Big Blue, survey, within ranges established in this study. Elkhorn, Little Blue, Missouri, Nemaha, Niobrara, Platte, and Upper Republican basins (Hoke, 1983, Discussion 1994b, 1995, 1996, 1997b, 2004, 2005a, 2005b, 2009), There are no previous statewide studies of Nebraska portions of this survey were compared to other mussels to compare against the current study to published reports from those regions, and were evaluate the effectiveness of the methods employed, found to compare favorably to those studies. In

12 2011 Transactions of the Nebraska Academy of Sciences 32, 1–46 Freshwater Mussels of Nebraska instances where other studies have documented reported Amblema plicata, thought to be a recent species where these were not collected in this study, colonization, from the reach below Gavins Point this appears to be attributable to intensive collection Dam. of comparatively limited stream reaches, ideal Survey results from relevant portions of the Big collecting conditions, or collections of isolated Blue, Little Blue, Nemaha, and upper Kansas basins populations. and the Missouri River (Hoke, 1996, 1997b, 2004, A number of surveys have been completed in or 2005b, 2009) may be compared with results of several adjacent to Nebraska since publication of my earlier recently published Kansas surveys. Bergman et al. papers, and deserve to be discussed. Peyton and (2000) recovered 19 species from the upper Kansas Maher (1995) collected seven species from 28 sites in drainage, including one, Potamilus alatus, not four counties in the Middle Platte Basin including recovered from the basin in this survey (Hoke, one, Strophitus undulatus, not recovered from the 37 1997b). However this survey found 19 species sites sampled in the same area in this study (Hoke, including one, Lampsilis siliquoidea, not recovered by 1995). The former study was quantitative and Bergman et al. (2000), and significantly more conducted when irrigation canals and reservoirs were occurrences of all species for which information was either dewatered or drawn down, and involved given, than the former study. Unfortunately prolonged sampling efforts (Peyton and Maher, Bergman et al. (2000) do not present data by river, 1995). Of the 8,804 unionids sampled under those collection locales are not given, and occurrences are conditions, only 22 specimens (0.25%) were S. only presented for a few species, so further undulatus. Schainost (2003) recovered a single live comparisons are not possible. Angelo et al. (2009) Tritogonia verrucosa under extreme low water presented results of an eighteen-year survey of conditions from a site on the Big Blue River not Kansas unionoids conducted by the Kansas sampled in this survey. The author is aware of one Department of Health and Environment and the study of the Platte River and two of unchannelized Kansas Department of Wildlife and Parks. Those reaches of the Missouri River conducted recently by surveys documented a number of range extensions in the Nebraska Game and Parks Commission. The the upper Kansas Basin, and two relict occurrences of Commission did not provide copies of these surveys one species, Obliquaria reflexa, not found in my earlier for review, so they cannot be analyzed nor cited in surveys. The range extensions reflect a greater this paper; however, Duggan (2009a) noted one number of collection sites in western Kansas, 297 vs. survey did recover a single specimen of Leptodea 181. In contrast, Anodonta suborbiculata, Arcidens leptodon from the Missouri River. confragosus, Lasmigona compressa, and Quadrula Recent studies by the South Dakota Department of fragosa, reported from northeastern Kansas in this Game, Fish, and Parks in the unchannelized Missouri study (Hoke, 1996, 2004, 2005b, 2009), were not River along the Nebraska-South Dakota border recovered from the region by Angelo et al. (2009), (Perkins and Backlund, 2000; Shearer et al. 2005) may though more sites were sampled in that effort (over be compared against results from this survey (Hoke, 230) than the 95 locales in this survey. 1983, 2009), and one unpublished collection. Perkins Recent and historic collections from portions of and Backlund (2000) recovered two Anodonta the North and South Platte Basins in Wyoming and suborbiculata, four Lampsilis teres, and two Arcidens Colorado are compared with results from this and confragosus in the 2,064 specimens collected from 47 other studies in western Nebraska in Table 5. sites below Lewis and Clark Lake. The two former Museum vouchers from Colorado indicate a number species were recovered in this survey, though from of species not recovered from the South Platte Basin channelized reaches further downstream (Hoke, in this survey, however, recent collections in 1983; 2009). Arcidens confragosus was not collected Colorado suggest only one species, Pyganodon from the Missouri River in this study, but Leptodea grandis, is currently present (Cordeiro, 1999). Recent leptodon collected in this survey was not recovered by and historic collections in Wyoming have recovered a Perkins and Backlund (2000). Shearer et al. (2005) number of species from the North Platte Basin not found one Potamilus alatus, and two Utterbackia collected in this study. This may indicate a deficiency imbecillis among the 247 specimens recovered from 49 in this survey or merely reflect the impact of locales above Lewis and Clark Lake. Neither species extensive water diversions above Nebraska reaches. was collected from that reach in this survey, though The fact that the North Platte River in Nebraska is both were recovered from downstream reaches, and currently only one to two-tenths as wide as in 1865 the former upstream in the Lake Oahe impoundment may suggest upstream withdrawals are largely as well (Hoke, 2003). Shearer et al. (2005) also responsible (Williams, 1978). Further, at least some

2011 Transactions of the Nebraska Academy of Sciences 32, 1–46 13 E. Hoke Table 5. Freshwater Mussels Reported From the South and North Platte Basins in Colorado, Nebraska, and Wyoming

Basin South Platte North Platte Capital letters indicate condition and relative age of source records: L = Live; R = recent; RL = relict; H = Species NE CO WY NE WY historical report; R+H = recent and historical records; R- Anodontoides ferussacianus L H-Mc Rf L Rj M = recent museum voucher; and H-M = historical Lampsilis cardium – H?a – – Rj+Hk museum voucher.

Lampsilis siliquoidea – – – RLh Rj Lasmigona c. complanata L – – L – All records without superscript references are from this survey. Data sources by superscript are: aCockerell Leptodea fragilis H?a – – – – (1889); bPeyton and Maher (1995): cUCMNH, nos. 253, Ligumia recta – – – – Rj 258, 3606, 41594; dCordeiro (1999); eLos Angeles County Potamilus ohiensis Lb – – – Rj Museum, nos. 140605, 140606 as given in Cordeiro d Pyganodon grandis L L – L – (1999); fHoke (1995); gUCMNH, nos. 40916 and 40917; Strophitus undulatus – H-Me – – – hFreeman and Perkins (1992); iBaxa (1981); jEdwards Utterbackia imbecillis Lb – R-Mg Li – (2010), and kUCMNH, no. 8540. Species Reported 6? 4? 2 5 5 of the upstream diversity (i.e. Potamilus ohiensis and The former presence of Potamilus purpuratus in Utterbackia imbecillis) may be due to recent Nebraska and northern Kansas is less disconcerting introductions. when viewed with the perspective of survey results On the basis of the analysis above, I believe the and some knowledge of the minimal extent of results of this study fairly reflect the composition of historical collections in lower Missouri River Basin the unionid fauna of the regions surveyed. tributaries. Three species (Leptodea leptodon, Differences from other studies appear to be due to Pleurobema clava, Quadrula fragosa) were first concentrated collecting in limited stream reaches documented from the Missouri River Basin in this (Peyton and Maher, 1995; Perkins and Backlund, survey (Hoke, 1983, 1997a), and new Nebraska and 2000; Shearer et al. 2005; Angelo et al. 2009), superior Kansas records for Lasmigona compressa are the first collecting conditions (Peyton and Maher, 1995; from the basin since Tryon’s (1868) publication. A Schainost, 2003), colonization subsequent to my single museum voucher documents the former original survey (Shearer et al. (2005), better access to presence of Villosa lienosa in the Missouri River stream collection areas (Perkins and Backlund, 2000; Basin. These species are or appear to have been Shearer et al. (2005), and possibly more favorable extremely uncommon in the region. Rivers and conditions above Nebraska reaches (Cvancara, 2005; streams in northeastern Kansas, northern Missouri, Edwards, 2010). These largely reflect the financial southern and western Iowa, and Nebraska were not and logistical constraints of this study. adequately sampled before severe habitat A number of species recovered in this survey are degradation due to erosion from the tilling of the far beyond their generally known ranges. Angelo et native and subsequent extensive al. (2009) have questioned the identification of one of channelization in and before the early twentieth these, Potamilus purpuratus, from the Kansas drainage century, and much of this region remains poorly in Kansas (Scammon, 1906; Liechti and Huggins, sampled today. Given the level of research in the 1977; Hoke, 2005b) due to a similarity of shell traits in basin, it is not surprising relatively uncommon some specimens of Potamilus alatus and P. purpuratus, components of the unionid fauna were not collected. and chosen to assign the preceding specimens to P. As rivers in the basin are subjected to more alatus in their recent publication. While this thorough examination, additional specimens of treatment may be more aesthetically appealing than some of these species have been recovered (Bleam et the former presence of populations of a species rarely al. 1998; Skadsen, 1998; Perkins and Backlund, 2003; reported within the Missouri River Basin, the initial Hoke, 2009; Duggan, 2009a). This suggests identifications are retained in this paper. The knowledge of the former richness of the unionid identifications of all specimens of this species were fauna of the lower Missouri River Basin, particularly verified by The Ohio State Museum of Biological the more uncommon species, is deficient and Diversity, as was a museum specimen from Papillion probably reflects only the limited extent of early Creek that is clearly P. purpuratus. research in the region.

14 2011 Transactions of the Nebraska Academy of Sciences 32, 1–46 Freshwater Mussels of Nebraska The distributions documented in this study populations of potential host fish. Rivers running reflect an amalgam of environmental conditions, from western Nebraska generally have sandy both natural and anthropogenic, as well as a substrates and tend to flow in relatively straight lines temporal component evidenced by collections of or gradual arcs with little meandering (Fennemann, relict shells. The natural factors are discussed in 1931). This general orientation combined with the depth in the first subsection below and presented as steady decrease in elevation to the east promotes a model of the pre-settlement unionid distributions relatively rapid currents and generally shifting sand of Nebraska. This model utilizes results from creeks substrates. In this study, Great Plains river habitats and rivers in the current study supplemented by supporting unionids were headwater areas, side observations of early explorers and travelers to channels, backwaters, and sloughs. Mussels were postulate a view of unionid habit and distributions usually uncommon in main channel habitats (Hoke, before the agricultural development of the state. 1994a, 1994b, 1995, 1997b, 2005a). Necessarily, this view is quite general. Historical In the eastern United States, large rivers tend to changes in the aquatic habitats of Nebraska are have greater diversity than smaller streams (Watters, developed in a subsequent subsection. 1992). In contrast, in this study, western Nebraska rivers were often found to contain less diversity than their tributaries. This reflects the impact of the Natural (Pre-Settlement) Aquatic Environments in predominantly shifting sand substrates characteristic Nebraska of these rivers. In the middle and lower Loup Unionid distributions in Nebraska were and continue system, of forty-one sites sampled in river habitats to be heavily impacted by geologic, hydrologic, and only two produced mussels and these were in climatic parameters. Relevant factors include habitats sheltered from upstream currents. In the precipitation, drainage development, stream Loup and upper Republican basins the greatest permanency, current velocity, sediment load, host diversity is in tributary creeks, while basin rivers fish diversity, and substrate composition and support almost no mussels (Hoke, 1994a, 1997b). stability. These factors are increasingly unfavorable Productive reaches of tributary creeks have slow for unionids westward in the Great Plains, and currents, and substrates of mud, sand, or mud and relatively favorable in the Dissected Till Plains. sand. These tributaries may be viewed as mussel Heavy sediment loads were detrimental to mussels in refugia in the predominant adverse shifting sand the historic Platte and Missouri rivers. Given environments of the major western drainages. perennial stream flow and host fish availability, the Mussel distributions in such drainages often consist factor that most consistently limits unionid presence of discontinuous populations in widely separated throughout the state is substrate stability. Mussels patches of viable habitat. were usually absent entirely from unstable Mussels are susceptible to removal from substrates, and when found in such habitats did not substrates, especially shifting sand substrates, by survive over time. current shear during peak flow events (Strayer, Substrate instability is largely a product of 1999; Gangloff and Feminella, 2007). Seasonal peak substrate composition and current velocity, and can flows formerly occurred on the Platte and Missouri be augmented by the presence of heavy sediment Rivers due to melting of snow on the High Plains to loads. Sandy substrates coupled with rapid currents the west and northwest and to melt water from the produce shifting sand bottoms, and these have long Rocky Mountains. Both rivers carried large been known to negatively impact unionids (Baker, quantities of sediment from natural erosion of the 1928; Murray and Leonard, 1962). The deleterious eastern slopes of the Rocky Mountains as well as impact of unstable substrates have been repeatedly from the plains to the east (Hayden, 1862; Mattes, emphasized in this study (Hoke, 1994a, 1994b, 1995, 1969), and were known for rapid currents 1996, 1997b, 2005a, 2009), and the importance of (, 1804 as given in Moulton, 2003; substrate stability has been recognized as a key Schneiders, 1999). Flash floods also served to scour determinant of regional and local mussel the unstable sandy substrates of Great Plains rivers. distributions in other studies as well (Holland- The upper Republican basin was particularly Bartels, 1990; Brim Box and Mossa, 1999; Strayer, susceptible to flash flooding, a phenomenon that 1999; Gangloff and Feminella, 2007). claimed hundreds of lives (Hoffman, 1983b; In the Great Plains, precipitation and drainage Mohlman, 1993), and occasioned the construction of development increasingly decline westward (Table six dams in the region after 1935. Nebraska rivers 6). Rivers are generally wide and shallow with few with predominantly shifting sand substrates are the of the deeper holes that provide habitat for diverse middle and lower reaches of the Elkhorn, Little

2011 Transactions of the Nebraska Academy of Sciences 32, 1–46 15 E. Hoke Blue, Loup system, and Niobrara rivers, and all Stream substrates in the Dissected Till Plains Nebraska reaches of the North Platte, Platte, ranged from pebble and cobble to mud and mixtures Republican, and South Platte rivers. of mud and sand. Substrate diversity in this region The substrates of the historic Missouri River were correlates with the presence of Pre-Illinoian glacial perhaps the ultimate example of instability. The Mis- debris. Over time rock washed from overlying till and souri River was known for turbidity, rapid deposi- became a component of stream substrates. The Big tion of sediment, shifting sand and mud bars, fre- Blue, Big Nemaha, and Little Nemaha cut through quent channel movement, and a rapid current (Hay- bedrock at numerous points in southeastern Nebraska, den, 1862; Utterback, 1914, 1915-1916, 1917; Over, and rock washed from these cuts was incorporated 1915; Schneiders, 1999), factors that undoubtedly into substrates below. Many streams in the region produced unstable substrates. Below the confluence were also relatively clear. In 1804, (as with the Platte River, the Missouri was essentially a cited by Grier, 1983) reported the Elkhorn River as braided stream due to the quantity of sand input “about one hundred yards wide, with clear water and from the Platte River (Pierce, 1983). The Missouri was a gravelly channel”. The Big Blue River was named for reported to be uninhabitable for freshwater mussels the blue color of some of its deeper pools (Andreas, due to the heavy load of silt and other sediment in its 1882). In 1804, William Clark noted the Big Nemaha waters (Hayden, 1862; Coker and Southall, 1915; was “a Butifull River of Clear water of about 80 yards Over, 1915, 1942; Utterback, 1915-1916, 1917; Bartsch, wide” (Moulton, 2003). The former diversity and 1916) though support for this view appears more stability of substrates and clarity of water is reflected anecdotal than research based, and is contradicted by in the diversity of current and relict unionid species Simpson (1900) and a small number of early vouchers recovered in this survey or represented by nineteenth from South Dakota reaches (Hoke, 2009). There were, century museum vouchers. however, many backwaters, chutes, sloughs, attached The Dissected Till Plains may be viewed as a lakes, and detached lakes along the river and proba- region of relatively favorable mussel habitat bly some isolated habitats in the main channel where surrounded by more adverse habitat zones, the Great currents were slow and substrates stable and these Plains to the west and the Missouri River eastward. may have supported some silt-tolerant unionid spe- This pattern is repeated in the Kansas drainage in cies (Hoke, 2009). Historically, unionids were found northern Kansas, and in southern South Dakota, in slow water habitats in and along the Missouri though it is less pronounced in the former, and more River (Simpson, 1900; Utterback, 1915-1916, 1917), accentuated in the later. In both regions, unionid and were probably largely absent from the main diversity is concentrated in formerly glaciated areas, channel. Two species, Lasmigona c. complanata and and diminishes in the Great Plains and along the Pyganodon grandis, are documented by early vouchers Missouri River. from Crystal Lake, a Missouri River oxbow, in north- eastern Nebraska. Given the near absence of early Post Settlement Modification of Aquatic Habitat collection efforts, it is likely this is not a complete While natural factors still exert the predominant species list for the early Missouri River and associ- influence upon unionid distributions in Nebraska, ated oxbows along the Nebraska border. agricultural development has significantly modified In contrast to western Nebraska streams and the many aquatic habitats. Observations during this sur- Missouri River, streams in the Dissected Till Plains vey, supplemented by conversations with landowners, had slower currents, more diverse substrates, lighter and an extensive literature review suggest anthropo- sediment loads, and greater substrate stability. The morphic activities with the greatest effect upon Nemaha and Elkhorn rivers and many eastern Nebraska mussels include surface and subsurface irri- Nebraska creeks were once characterized by gation, construction of impoundments and canals, significant meandering. Meanders promote formation stream channelization, erosion/sedimentation, inten- of deep holes that provide habitat diversity for sive grazing, contaminants, and the introduction of mussels and potential host fish and also decrease invasive species. stream gradients and current velocity. Further, many Withdrawal of water from streams for irrigation of streams in eastern Nebraska flow north to south, croplands is common throughout Nebraska, but is betraying their glacial origin and promoting slower most developed in the Great Plains, where storage currents. For example, the Big Blue River flows at reservoirs have been constructed on rivers and major right angles to the general east to west uplift that streams, and water is transported by extensive canal underlies the state, flowing more along than across systems from these impoundments or directly from contours, resulting in lower stream gradients and rivers to croplands. Surface water diversions are most current velocities than in rivers in the Great Plains. significant in the Middle, North, and South Platte

16 2011 Transactions of the Nebraska Academy of Sciences 32, 1–46 Freshwater Mussels of Nebraska basins, and in the Republican Basin, and result in all scenarios short of transbasin water infusion. The severe degradation of stream habitats (Bentall, 1982; impact of subsurface withdrawals is not included in Hoffman, 1983a, 1983b; Hoke, 1995, 1997b). Severe the figures for degraded stream kilometers given in declines from upstream irrigation withdrawals are Table 6, since the greatest increase in center pivot documented for the North and South Platte rivers as systems occurred after those figures were compiled. early as the late 1870’s and 1880’s (Bentall, 1982). Between 1972 and 1988 the number of center pivot Anecdotal accounts from western Kansas and eastern systems in use in Nebraska increased from 2,725 to Colorado describe similar dramatic flow decreases 27,617 or over 913 percent (Sheffield, 1993a). The for central plains rivers and streams in those regions number of registered irrigation wells in the state rose (Mead, 1896; Henderson, 1920). from 42,899 in 1972 to 75,363 in 1991, an increase of In this study, mussels were encountered only in 32,464 wells or 76 percent (Sheffield, 1993b). Nearly all the eastern portion of the South Platte Basin, largely the increase was in the Great Plains habitat zone (Mack from the Sutherland canal and associated reservoirs et al. 1996a). supplied primarily with water from the North Platte Construction of impoundments and canals has River. Western portions of the basin were not created some new aquatic habitats for mussels in productive reflecting the near absence of water in the Nebraska (Figure 39). Thirteen unionid species have during sampling (Hoke, 1995). been collected from these artificial lentic and lotic Mussels were restricted in the North Platte Basin to environments (Table 7). Most species were repre- reservoirs, ponds, canals, and a few backwater areas sented by only a few survey occurrences; however, along the North Platte in this survey, and diversity some species appear to thrive in these habitats. was limited. Mussels continue to survive in some Uniomerus tetralasmus is common in farm ponds and reaches of local creeks in Great Plains basins, though reservoirs in the Dissected Till Plains. Anodontoides these habitats too are often tapped for surface ferussacianus, Lasmigona c. complanata, Potamilus irrigation. Water rights allocated along many smaller ohiensis and Quadrula quadrula are quite common in Nebraska streams exceed total flow during normal some Great Plains canals, and with one exception, A. years (Table 6), and many Great Plains streams that ferussacianus, in many western reservoirs as well formerly provided habitat for mussels are now nearly (Freeman and Perkins, 1992; Peyton and Maher, unpopulated (e.g. Shell Creek, Wood River). 1995; Hoke, 1995, 1997b). Pyganodon grandis is Large-scale water diversion projects are more common in all viable artificial habitats in the state, limited in the Niobrara and upper Loup basins where and many occurrences of Utterbackia imbecillis in this ranching is often the most important agricultural study were from artificial habitats as well. activity, however, in the lower Loup Basin, diversion The portion of these artificial habitats utilized by of water is increasing, and two new reservoirs were mussels is often quite limited. Most reaches of canals constructed during this study. Some mussels are are dewatered when irrigation activities are present in headwater reaches of the Niobrara and completed, and the levels of some irrigation Loup system rivers, and in some creeks in the Loup reservoirs drop substantially during the summer as Basin, though both habitats are in decline (Hoke, water is withdrawn for irrigation. The Davis Creek 1994a, 2005a). Surface water withdrawal in eastern Reservoir fluctuates by 13 meters during some years. Nebraska is less pervasive due to relatively greater The great extent of seasonal drops limits the value of precipitation. some Nebraska reservoirs to only a few species, and Subsurface water withdrawals have an increasing particularly favors Pyganodon grandis the most widely impact upon unionid habitat throughout western distributed mussel in this study (Riegle, 1967). Nebraska. The advent of center pivot irrigation A positive aspect of reservoir construction in and technology makes possible the irrigation of lands that adjacent to Nebraska is the great decrease in were formerly suitable only for dry land farming or sediment loads and turbidity of the Platte and grazing. Intensive development of wells in the Missouri rivers. Sediment from the Rocky Mountains Republican, Little Blue, and upper Big Blue basins, and formerly transported through Nebraska by the Platte in Box Butte County in the Niobrara Basin is River or eastward by the Missouri River now settles associated with significant declines in water tables beneath the waters of upstream reservoirs, and (Mack et al. 1996a, 1996b). Headwaters and many downstream flows are less turbid than in the past. tributaries of the Little Blue River and upper Big Blue Leptodea leptodon and Lampsilis teres, are reported to River now dry up completely in some years (Hoke, be relatively intolerant to silt (Parmalee and Bogan, 2004, 2005b). Huntoon (1974) forecast continued 1998; Brim Box and Mossa, 1999), but occur today in declines in the water of the upper Big Blue Basin under the Missouri River, where silt content was formerly

2011 Transactions of the Nebraska Academy of Sciences 32, 1–46 17 E. Hoke Table 6. Nebraska Stream Condition Statistics In 19731 Original Dewatered/ Basin Stream Stream Channelized Polluted Area Drainage Turbidity Soil Water 2 Basin (km) (km) (km) (km ) Development2 Impact3 Stability4 Rights5 Big Blue 2,691.7 117.5 167.3 11,836 4.40 79 H E Elkhorn 2,492.8 467.7 72.4 18,130 7.27 77 H E Little Blue 1,488.6 31.9 168.9 6,863 4.61 91 H E Loup 2,734.2 117.9 48.3 39,446 14.43 60 H E Lower Platte 1,227.3 111.0 62.8 8,055 6.56 74 H E Middle Platte 1,089.7 76.6 265.5 13,287 12.19 91 H E Missouri Tributaries 1,088.2 40.7 40.2 7,641 7.02 67 NG NG Nemaha 2,320.8 264.0 11.3 7,148 3.08 47 H E Niobrara 2,523.4 22.0 32.2 30,743 12.18 20 H E North Platte 677.2 14.5 222.0 18,493 27.31 34 NG E Republican 1,889.6 62.4 728.9 24,993 13.23 63 H NG South Platte 464.5 13.7 186.6 8,158 17.56 25 NG NG White/Hat Creek 557.2 2.9 24.1 5,517 9.90 28 NG E Total/Average 21,245.2 1,342.8 2,030.5 200,310 9.43 6Eastern Nebraska 9,820.8 1,000.9 354.0 52,810 5.38 7Western Nebraska 11,424.4 341.9 1,676.5 147,500 12.91 1All data obtained or derived from Bliss and Schainost (1973a-m) 2Calculated as basin area (km2) divided by original stream km. 3The percent of streams impacted by turbidity. 4H = highly erodable; NG = not given in source materials. 5Extent water rights exceed total stream flow on small and intermediate sized streams during years of low or normal flows: E = exceed low or normal flows; NG = not given in source materials. 6Includes the Big Blue, Elkhorn, Lower Platte, Missouri Tributaries, and Nemaha basins 7Includes the Little Blue, Loup, Middle Platte, Niobrara, North Platte, Republican, South Platte, and White/Hat Creek basins

high (Hoke, 1983, 2000a, 2009; Perkins and Backlund, 2000; Duggan, 2009a). Reservoir dams control and moderate Table 7. Unionid Species Recovered From Canal, downstream flows, and prevent or lessen high flows Reservoir, and Pond Habitats in Nebraska* that can scour river substrates and remove embedded Sand mussels. In the upper reaches of the Middle Platte Pits & River, the diversion of 82% of upstream flow (Bentall, Species Canals Reservoirs Ponds 1982), decreases the magnitude of peak flow events Anodontoides ferussacianus X2,3 F X2 below and thus limits associated scouring of Lasmigona c. complanata X2,3 X3 – substrates. Some mussels now inhabit the river’s Leptodea fragilis X X – main channel in this area. Potamilus alatus – M – Reaches immediately below dams can be quite Potamilus ohiensis X2,3 X2,3 – productive for mussels. Current velocity increases Pyganodon grandis X2,3 X1,2,3 X below dams, but is at a minimum in pools immedi- Quadrula quadrula X2,3 X3 – ately below dams. In a survey of 47 sites in the Strophitus undulatus P – – unchannelized Missouri River below the Gavins Point Toxolasma parvus – X3 – Dam, the three sites immediately below the dam pro- Truncilla truncata – X – duced 71% of all live and dead unionids collected Uniomerus tetralasmus – X X (Perkins and Backlund, 2000). In the Great Plains, Utterbackia imbecillis X2,3 X1,2,3 X pools below dams can provide refugia from the gener- Total Species 8 11 4 ally rapid currents and associated unstable substrates characteristic of the region, and may support mussels *X = collected in this study; F=collected only by Freeman and Perkins (1992); P = collected only by Peyton and Maher (1995); and while lower reaches may be largely unoccupied. M = museum specimen, Nebraska State Museum. Superscript Construction of low dams along the Big and Little numerals indicate species also collected in other studies as follows: Blue rivers in southeastern Nebraska, a region 1Baxa (1981); 2Freeman and Perkins (1992); 3Peyton and Maher formerly rich in unionid diversity, probably had an (1995).

18 2011 Transactions of the Nebraska Academy of Sciences 32, 1–46 Freshwater Mussels of Nebraska

Figure 39. Major reservoirs and canals in or adjacent to Nebraska. Reservoirs indicated by numerals and canals by letters as follows: 1 = Box Butte Reservoir; 2 = Calamus Reservoir; 3 = Davis Creek Reservoir; 4 = Elwood Reservoir; 5 = Enders Reservoir; 6 = Harlan County Reservoir; 7 = Harry Strunk Lake; 8 = Hugh Butler Lake; 9 = Jeffrey Reservoir; 10 = Johnson Lake; 11 = Lake Babcock; 12 = Lake Maloney; 13 = Lake McConaughey; 14 = Lake Minatare; 15 = Lewis and Clark Lake; 16 = Merritt Reservoir; 17 = Sherman Reservoir; 18 = Sutherland Reservoir; 19 = Swanson Reservoir; A = Courtland Canal; B = Cozad Canal; C = Dawson County Canal; D = Gothenburg Canal; E = Interstate Canal; F = Loup Power Canal; G= Phelps Canal; H = Sutherland Canal; and I = Tri County Supply Canal.

extremely adverse impact upon mussels. Subsequent formerly meandering streams, increased stream to settlement of the area, at least 35 dams were gradients, and current velocity, and destroyed deeper constructed on the Big Blue River and 14 on the Little holes that provided habitat for diverse populations of Blue River (Bouc, 1983). In total these dams potential host fish. Table 8 illustrates the extent of converted a significant portion of both rivers into the loss in selected streams in the Nemaha and lentic habitat, rendering inundated reaches Elkhorn Basins. The direct effect of this process on unsuitable for many unionid species (Vaughn and mussels in Nebraska rivers is not documented, Taylor, 1999). Kansas and lower Nebraska reaches however, Missouri River tributaries in northern once supported a diverse fauna of 22 species and 24 Missouri (the Grand, Chariton, Nodaway, and Tarkio species for the Little Blue and Big Blue rivers rivers) and the Vermillion River in southeastern respectively (Hoke 2004, 2005b), however, diversity is South Dakota, were channelized during the early lower in most Nebraska reaches. Though most of the 1900’s and thousands of stranded mussels were dams have been destroyed, probably increasing reported in the by-passed channels at that time viable lotic habitat in upstream reaches, remaining (Utterback, 1914; Coker and Southall, 1915). dams may preclude repopulation of lotic unionid Today, channelized stream reaches in the species by blocking the upstream movement of Dissected Till Plains contain few living mussels. infected host fish (Watters, 1996). Channelized portions of the Nemaha rivers are One of the most destructive aspects of agricultural largely devoid of any live mussels. These reaches development in Nebraska is stream channelization. now often have shifting sand substrates, and in the The focus of stream channelization is in eastern summer, a more or less uniform depth of around 0.3 Nebraska, which includes the region of greatest meters. Substrates in the middle and lower Elkhorn unionid diversity (Table 6). The Big Nemaha, River are now predominantly shifting sand and were Elkhorn, and Little Nemaha rivers and many larger not productive in any survey (Clausen and Havlik, creeks were extensively channelized during the late 1994; Hoke 1994b). Frest (1987) reported similarly nineteenth and early twentieth centuries (Bentall et al. catastrophic destruction of habitat and limited 1971; Delich, 1983). Straight channels cut along these diversity in the dredged rivers of western Iowa, and

2011 Transactions of the Nebraska Academy of Sciences 32, 1–46 19 E. Hoke noted “mussels were either completely eradicated Table 8. Channelization of Selected Interior Nebraska — (the common finding) or reduced to a single species Streams Nemaha and Elkhorn Basins nearly everywhere examined.” The only exception in Basin Current Original Lost Per- that study were five sites on a six mile reach in the Stream / Segment (km) (km) (km) cent headwaters of the Boyer River where fifteen species 1 were recovered, attesting to the former diversity of Nemaha Basin Big Nemaha 31.5 61.1 29.6 48.4 the western Iowa mussel fauna. Big Nemaha, Middle Channelization of the Missouri River below Ponca Branch 34.4 36.2 1.8 4.9 State Park in northeastern Nebraska was completed Big Nemaha, North in the mid twentieth century. This process directly or Fork 109.4 164.3 54.9 33.4 indirectly eliminated most of the natural slow water Big Nemaha, South stable substrate habitats along the river such as Fork 49.7 80.9 31.2 38.6 chutes, side-channels, sloughs, backwaters, and Total Big Nemaha 225.0 342.5 117.5 34.3 attached lakes and led to the near total elimination of adjacent riparian forest habitat (Schneiders, 1999). Little Nemaha 122.5 160.6 38.1 23.7 Today, the lands bordering the river are often farmed Little Nemaha, North Fork 56.7 62.3 5.6 9.0 nearly to the edge of riverbanks. The channelized Little Nemaha, South Missouri River is three times as swift as in former Fork 40.6 47.3 6.7 14.2 times (Schneiders, 1999), and the river bottom was Total Little Nemaha 219.8 270.2 50.4 18.7 described in one research study as a “biological semi desert” of moving waves of sand (Sayre and All other streams in basin 1,612.0 1,708.1 96.1 5.6 Kennedy, 1978). Remaining slow water areas, now primarily pools below wing dams, support a number Total 2,056.8 2,320.8 264.0 11.4 of unionid species, and rock revetments (when 2 interstices have filled with sediment) provide stable Elkhorn Basin and possibly significant habitat along the river as Elhorn River 444.7 596.7 152.0 25.5 Logan Creek 133.3 215.2 81.9 38.1 well (Hoke, 2009). All other streams in Relatively few unionid species are tolerant to basin 1,447.1 1,680.9 233.8 13.9 excessive amounts of silt. Ellis (1931, 1937) attributed Total 2,025.1 2,492.8 467.7 18.8 the demise of many formerly productive mussel beds 1Nemaha Basin data from Bliss and Schainost (1973c) to accumulations of silt on stream bottoms. Erosion 2Elkhorn Basin data from Bliss and Schainost (1973f) is a significant problem throughout Nebraska (Table 6), but its impact on mussels is most significant in the often denied stream access. The animals compact Dissected Till Plains. Rainfall is heaviest in eastern and level substrates, crush unionids, and trample and Nebraska, soils are highly erodable, and the region is consume streamside vegetation that anchors soil intensively farmed, often to the edge of stream banks, along stream banks. This process increases soil resulting in significant erosion of topsoil (Clausen erosion, which fills the deeper holes and and Havlik, 1994; Hoke, 1994b, 1996, 2004, 2005b). consequently degrades habitat for many fish species. Rivers once reported to be relatively clear are now In the sandy soils of the Niobrara and Loup basins, quite turbid. In some instances, streambeds are cattle cave in stream banks ultimately widening blanketed with a foot or more of silt, covering earlier streams, and decreasing average depth. The animals pebble or cobble substrates (Hoke 1994b), and thus crush relict shells, and after a period of time, no destroying the value of these habitats for many evidence remains to document the former presence of mussel species. Silt fills up deeper holes in rivers and mussels in many habitats (Hoke, 2004). Many small streams and eliminates habitat for many fish species creeks that formerly supported mussels are now (Bliss and Schainost, 1973a, 1973b, 1973c, 1973f). The largely depopulated, while reaches of the same combined impact of channelization and streams, protected from livestock by fencing, may erosion/siltation were probably lethal to many continue to support isolated populations of some unionid populations in eastern Nebraska. species (Hoke, 1994b). Grazing of domesticated livestock along and in The impact of urine and feces expelled directly rivers and streams is detrimental to unionids into streams by livestock can be severe. Profit (1967) throughout Nebraska, though its impact is most notes runoff from feedlots decreases dissolved significant in the Great Plains. In contrast, in much of oxygen, and increases the amount of ammonia and southeastern Nebraska, streams may be deeply fecal coliform bacteria in affected streams. Feedlot incised into the surface, and domestic livestock are runoff is associated with fish kills (Profit, 1967, Profit

20 2011 Transactions of the Nebraska Academy of Sciences 32, 1–46 Freshwater Mussels of Nebraska and Edwards, 1973), and is a particularly serious River and many tributary streams as well. Large problem in the Elkhorn River Basin (Clausen and populations of C. fluminea were present in Wilson Havlik, 1994; Hoke, 1994b), and probably in the Little Lake, an impoundment of the Saline River in Blue River and some of the small creeks paralleling northwestern Kansas, in 1983 (Hoke, 1997b), and the the Platte River in east central Nebraska as well. species was widely distributed in the Missouri River Starrett (1971) found no living mussels in the upper east of Kansas City, Missouri by 1990 (Hoke, 2009). River where ammonia nitrogen levels were in In this study, C. fluminea was confined to a small excess of 6 ppm, but noted mussels began to appear number of locations in the Platte River system (Hoke, in downstream reaches where levels were 1995), however, it is probably much more widespread diminished. High concentrations of dissolved at present. Corbicula fluminea is now widely ammonia are associated with an absence of live distributed in northern Kansas, and the first colonies mussels (Environmental Protection Agency, 2009). of the zebra mussel have also appeared (Angelo et al. Sewage and industrial pollution were occasionally 2009). The zebra mussel has recently colonized the noted during this study and both were associated Missouri River at Sioux City and below Gavins Point with an absence of living mussels in localized stream Dam, and one lake in eastern Nebraska (Missouri reaches. A more widespread problem is the impact of Department of Conservation, 2001; Duggan, 2009b). chemical and other agricultural contaminants on Both species have significant reproductive unionid mortality and reproduction. Though these advantages over unionoids since larval forms are free are poorly understood, there is little doubt swimming and do not need a parasitic stage to contaminants play a major role in the decline of mature, and both compete directly with native freshwater mussels (Havlik and Marking, 1987). The mussels for food and bottom habitat. These bivalves effect of chemicals on unionid sperm is unstudied, may become a threat to native mussels in many and the impact of various chemicals and Nebraska habitats. combinations of chemicals upon unionid life stages has also received little attention, though some recent A Model of Nebraska Unionid Distributions studies suggest these may be severe (Jacobson et al. Climatic, geologic, and hydrologic factors delineate 1997; Conners and Black, 2004). three unionid faunal zones in Nebraska: the In this study, contaminants or evidence of them Dissected Till Plains, Great Plains and the Missouri were occasionally noted in the form of algal blooms River and floodplain. Given the importance of and associated destruction of unionid populations, perennial stream flows and host fish diversity which however, I believe their greatest impact may be in the decrease westward in the Great Plains, the primary interruption of the unionid reproductive cycle. factors influencing mussel distributions and diversity Nebraska streams often did not provide much in Nebraska are substrate composition and stability. evidence of recruitment. In many streams individual Shifting sand substrates are characteristic of the mussels were widely scattered, and it was unclear if Missouri River and most reaches of rivers in the enough individuals remained to successfully breed. Great Plains, while generally diverse and stable It is possible this observation is the product of survey substrates are relatively common in the Dissected Till methods that were not designed to collect juvenile Plains. specimens; however, considerable recruitment was The best unionid habitat in Nebraska is the 160 noted in the canals of central Nebraska. km wide section of eastern Nebraska encompassed in A key difference in the water quality of streams the Dissected Till Plains habitat zone. This region and canals is that the former contain runoff from receives more precipitation, has a more developed cropland whereas the later do not. Many unionid drainage, provides more diverse habitat for host fish, species move into shallow water to reproduce in the and contains more stable and diverse substrates than late summer (Murray and Leonard, 1962), and warm, surrounding regions. Streams in the Dissected Till bank full return flows, laden with chemicals and Plains once supported 29 of the 31 unionid species sediment from irrigated fields may impact unionid documented for Nebraska, and possibly others as reproduction at that critical time. Thus, the negligible well. Subsequent to settlement of the state, many recruitment observed in many streams may be streams in the region were subjected to extensive associated with chemicals and sediment washed from channelization, and the effects of poor farming cropland. Additional research is needed to validate practices led to severe erosion and resultant or disprove this association. sedimentation, together destroying or degrading Within the past twenty-five years, the Asiatic clam much of the best unionid habitat. A series of low (Corbicula fluminea) and the zebra mussel (Dreissena dams inundated much habitat in the Big and Little polymorpha) have colonized much of the Missouri Blue rivers. Runoff of chemical fertilizers, herbicides,

2011 Transactions of the Nebraska Academy of Sciences 32, 1–46 21 E. Hoke and insecticides from adjacent cropland and Lincoln, who provided valuable encouragement for several competition from invasive species pose further years thereafter. The Department of Anthropology, challenges to unionid populations in this region and University of Nebraska, Lincoln, provided a stipend to throughout Nebraska. study unionid distributions in the Republican River Basin in the summer of 1972. Bob Thomas, former Fisheries The Great Plains has probably always been Chief, at the Nebraska Game and Parks Commission relatively marginal habitat for mussels. Only donated field notes and vouchers from his collection seventeen unionid species were recovered from the efforts, provided encouragement during the early years of Great Plains habitat zone, and one of these, Potamilus the study, and also provided the contact information for alatus, is recently introduced. Rivers in this region state conservation officers that was utilized to mail a were and continue to be generally wide and shallow questionnaire on mussel locations in the state. The with shifting sand substrates. Unionid populations Colorado Division of Wildlife, Iowa Department of Natural were largely restricted to small tributaries and the Resources, Montana Department of Fish, Wildlife and headwaters, backwaters, sloughs, and side channels Parks, South Dakota Department of Game, Fish and Parks and the Wyoming Game and Fish Department provided of the major rivers. Subsequent to development of contact information utilized to conduct mail surveys on the region, many rivers were largely drained for freshwater mussels in those states. Dr. Harold Murray, irrigation, eliminating habitat in many slough and then of Trinity University, corroborated identifications backwater areas. Intensive grazing also heavily early in the study, and Dr. David H. Stansbery impacts streams in the region. Small tributaries and corroborated and occasionally corrected my identifications headwaters of some rivers continue to provide much of Nebraska vouchers, provided specimens for a synoptic of the remaining viable habitat, though many are collection, and also provided meals and a place to stay increasingly becoming degraded. A limited number during numerous visits to The Ohio State University of species have adapted to the canal and reservoir Museum of Biological Diversity in Columbus, Ohio. I am indebted to the following institutions and their habitats created by agricultural development, but staffs for access to collections and other courtesies other species such as Lampsilis cardium and Lampsilis extended: Field Museum of Natural History, Chicago, siliquoidea have largely been extirpated from the Illinois; Illinois Natural History Survey, Champaign, region, though populations persist in southeastern Illinois; Kansas Biological Survey, Lawrence, Kansas; Wyoming (Cvancara, 2005; Edwards, 2010). Missouri Department of Conservation, Jefferson City, The Missouri River was historically noted for high Missouri; National Museum of Natural History, silt content and unstable substrates and was Washington D. C., Philadelphia Academy of Natural generally believed to be uninhabitable for mussels Sciences, Philadelphia, Pennsylvania; The Ohio State (Hayden, 1862; Utterback, 1914, 1915-1916, 1917; University Museum of Biological Diversity, Columbus, Ohio; University of Colorado Museum of Natural History, Coker and Southall, 1915; Over, 1915, 1942; Bartsch, Boulder, Colorado; University of Michigan Museum of 1916). Scattered early vouchers and current research Zoology, Ann Arbor, Michigan; University of Nebraska – cast doubt on this assertion, and suggest viable Kearney, Department of Biology, Kearney, Nebraska; habitat existed primarily in the slow waters and University of Nebraska – Omaha, Department of Biology, stable substrates of a few main stem habitats and in Omaha, Nebraska; University of Nebraska State Museum, side channels, sloughs, backwaters, oxbows, and Lincoln, Nebraska; and Wayne State College, Department attached lakes (Hoke, 2009). All unionid species of Biology, Wayne, Nebraska. Gordon Edwards of the must have been relatively silt tolerant. The Wyoming Game and Fish Department provided access to construction of upstream dams has greatly decreased the Wyoming mussel database. Mark M. Peyton provided a copy of field notes with legal descriptions of collection sites the silt content of the river below and some silt and findings from research in the canals and lakes along intolerant species now live in these waters. the Platte River in Dawson, Gosper, and Lincoln counties. Channelization of the lower river eliminated most I am also indebted to landowners across the state for natural stable substrate habitats but created many physical access to collection sites, and for information pro- artificial slow water habitats such as pools below vided on the location of current and historic populations of wing dams, and stable substrates in some revetments unionids in Nebraska. A number of these individuals pro- as well. These artificial habitats and surviving vided specimens for this study. Finally, thanks are natural slow water habitats continue to support extended to the editor and the two anonymous reviewers unionid populations in the river. for useful comments on the initial version of this paper.

Acknowledgements Literature Cited A number of individuals and institutions contributed Aber, J. S. 1999. Pre-Illinoian glacial geomorphology and significantly to this project. This study began as a research dynamics in the central United States, west of the project for a graduate course on the Zoology of the Great Mississippi. Geological Society of America, Special Paper Plains taught by Dr. Carl Gugler, University of Nebraska – No. 337: 113-119.

22 2011 Transactions of the Nebraska Academy of Sciences 32, 1–46 Freshwater Mussels of Nebraska Andreas, A. T. 1882. History of the State of Nebraska. Vol. 1. Bliss, Q. P. and S. Schainost. 1973e. White River – Hat Creek Chicago, The Western Historical Company: 930 pp. Basin Stream Inventory Report. Nebraska Game and Angelo, R. T., M. S. Cringan, E. Hays, C. A. Goodrich, E. J. Parks Commission, Bureau of Wildlife Services, Aquatic Miller, M. A. VanScoyoc and B. R. Simmons. 2009. Wildlife Division: 12 pp + appendices A, B, and C. Historical changes in the occurrence and distribution of Bliss, Q. P. and S. Schainost. 1973f. Elkhorn Basin Stream freshwater mussels in Kansas. Great Plains Research 19: Inventory Report. Nebraska Game and Parks 89-126. Commission, Bureau of Wildlife Services, Aquatic Arbuckle, K. E., J. A. Downing, and D. Bonneau. 2000. Wildlife Division: 14 pp + appendices A, B, and C. Statewide Assessment of Freshwater Mussels (Bivalvia: Bliss, Q. P. and S. Schainost. 1973g. Loup Basin Stream Unionidae) in Iowa Streams: Final Report. Des Moines, Inventory Report. Nebraska Game and Parks Iowa Department of Natural Resources: 115 pp + Commission, Bureau of Wildlife Services, Aquatic enclosed data CD. Wildlife Division: 14 pp + appendices A, B, and C. Aughey, Samuel. 1877. Catalogue of the land and Bliss, Q. P. and S. Schainost. 1973h. Lower Platte Basin freshwater shells of Nebraska. Bulletin of the U. S. Stream Inventory Report. Nebraska Game and Parks Geological and Geographical Survey of the Territories 3(3): Commission, Bureau of Wildlife Services, Aquatic 697-704. Wildlife Division: 13 pp + appendices A, B, and C. Backlund, D. C. 2000. Summary of current known Bliss, Q. P. and S. Schainost. 1973i. Middle Platte Basin distribution and status of freshwater mussels Stream Inventory Report. Nebraska Game and Parks (Unionoida) in South Dakota. Central Plains Archeology Commission, Bureau of Wildlife Services, Aquatic 8(1): 69-77. Wildlife Division: 14 pp + appendices A, B, and C. Baker, F. C. 1928. The fresh water Mollusca of Wisconsin. Bliss, Q. P. and S. Schainost. 1973j. Missouri Tributaries Part II. Pelecypoda. Bulletin of the Wisconsin Geological Basin Stream Inventory Report. Nebraska Game and and Natural History Survey, University of Wisconsin Parks Commission, Bureau of Wildlife Services, Aquatic 70(2): 1-495. Wildlife Division: 13 pp + appendices A, B, and C. Bartsch, P. 1916. The Missouri River as a faunal barrier. Bliss, Q. P. and S. Schainost. 1973k. North Platte Basin The Nautilus 30: 92. Stream Inventory Report. Nebraska Game and Parks Baxa, M. D. 1981. Anodonta species of Lake McConaughy, Commission, Bureau of Wildlife Services, Aquatic western Nebraska. The Nautilus 95(4): 180-183. Wildlife Division: 14 pp + appendices A, B, and C. Beetle, D. E. 1989. Checklist of recent Mollusca of Bliss, Q. P. and S. Schainost. 1973l. Republican Basin Stream Wyoming, USA. Great Basin Naturalist, 49(4): 637-645. Inventory Report. Nebraska Game and Parks Bentall, R. 1982. Nebraska’s Platte River: A graphic Commission, Bureau of Wildlife Services, Aquatic analysis of flows. Nebraska Water Survey Paper 53. Wildlife Division: 13 pp + appendices A, B, and C. Conservation and Survey Division, Institute of Bliss, Q. P. and S. Schainost. 1973m. South Platte Basin Agriculture and Natural Resources, University of Stream Inventory Report. Nebraska Game and Parks Nebraska – Lincoln. Commission, Bureau of Wildlife Services, Aquatic Bentall, R. and others. 1971. Water Supplies and the Land – Wildlife Division: 12 pp + appendices A, B, and C. the Elkhorn River Basin of Nebraska. Lincoln, University Bogan, A. E. 1993. of Nebraska Conservation and Survey Division: 51 pp. (Mollusca: Unionoida): a search for causes. American Bergman, S. M., M. E. Eberle, and B. K. Obermeyer. 2000. Zoologist 33: 599-609. Freshwater mussels (Bivalvia: Unionoidae) in streams Bolick, M. R. 1993. Samuel Aughey, Jr.: The controversial of northwestern Kansas. Naturalist 32: 1-15. first director of the University of Nebraska State Bleam, D. E., C. H. Cope, K. J. Couch, and D. D. Distler. Museum. Museum Notes No. 84, 4 pp. University of 1998. The winged mapleleaf, Quadrula fragosa (Conrad Nebraska State Museum. 1835) in Kansas. Transactions of the Kansas Academy of Bouc, K. 1983. River portraits: The Blues. NebraskaLand Science 101(1-2): 35-38. Magazine 61(1): 82-89. Bliss, Q. P. and S. Schainost. 1973a. Big Blue Basin Stream Bovbjerg, R. V., N. L. Pearsall, and M. L. Bracken. 1970. Inventory Report. Nebraska Game and Parks A preliminary faunal study of the upper Little Sioux Commission, Bureau of Wildlife Services, Aquatic River. Proceedings of the Iowa Academy of Science 77: Wildlife Division: 13 pp. + appendices A, B, and C. 177-184. Bliss, Q. P. and S. Schainost. 1973b. Little Blue Basin Stream Brandauer, N. and Shi-Kuei Wu. 1978. The bivalvia of Inventory Report. Nebraska Game and Parks Colorado. Part 2. The freshwater mussels (Family Commission, Bureau of Wildlife Services, Aquatic Unionidae). Natural History Inventory of Colorado 2: 41- Wildlife Division: 12 pp. + appendices A, B, and C. 60. Bliss, Q. P. and S. Schainost. 1973c. Nemaha Basin Stream Brim Box, J. and R. M. Mossa. 1999. Sediment, land use, and Inventory Report. Nebraska Game and Parks freshwater mussels: prospects and problems. Journal of Commission, Bureau of Wildlife Services, Aquatic the North American Benthological Society 18: 99-117. Wildlife Division: 13 pp + appendices A, B, and C. Brim Box, J., R. M. Dorazio, and W. D. Liddell. 2002. Bliss, Q. P. and S. Schainost. 1973d. Niobrara Basin Stream Relationship between streambed substrate Inventory Report. Nebraska Game and Parks characteristics and freshwater mussels (Bivalvia: Commission, Bureau of Wildlife Services, Aquatic Unionidae) in coastal plain streams. Journal of the North Wildlife Division: 15 pp + appendices A, B, and C. American Benthological Society, 21: 253-260.

2011 Transactions of the Nebraska Academy of Sciences 32, 1–46 23 E. Hoke Burch, J. B. 1975. Freshwater Unionacean clams (Mollusca: Cummings, K. S. and C. A. Mayer. 1992. Field Guide to Pelecypoda) of North America. Revised edition. Hamburg, Freshwater Mussels of the Midwest. Champaign, Illinois Michigan, Malacological Publications: xi + 204 pp. Natural History Survey, Manual 5: xii + 194 pp. Call, R. E. 1885a. Contributions to a knowledge of the Cvancara, A. M. 1975. Aquatic malacogeography of North fresh-water Mollusca of Kansas, I, fresh-water bivalves. Dakota. North Dakota Academy of Science Proceedings Bulletin of the Washburn College Laboratory of Natural 27(2): 68-82. History 1(2): 48-51. Cvancara, A. M. 1983. Aquatic Mollusks of North Dakota. Call, R. E. 1885b. Contributions to a knowledge of the Report of investigation no. 78, North Dakota Geological fresh-water Mollusca of Kansas, III, fresh-water Survey, v + 141 pp. bivalves. Bulletin of the Washburn College Laboratory of Cvancara, A. M. 2005. Illustrated Key to Wyoming’s Natural History 1(3): 93-97. Freshwater Mussels. Casper, Wyoming: 5 pp. Call, R. E. 1885c. Contributions to a knowledge of the Delich, C. 1983. River portraits: The Nemahas. fresh-water Mollusca of Kansas, IV. Bulletin of the NebraskaLand Magazine 61(1): 115-118. Washburn College Laboratory of Natural History 1(4): 115- Duggan, J. 2009a. Game and parks lists endangered 123. mussel. Lincoln Journal Star, Friday, March 13, 2009. Call, R. E. 1886. Fifth contribution to a knowledge of the Duggan, J. 2009b. Stopping the zebra mussel invasion. fresh-water Mollusca of Kansas. Bulletin of the Washburn Lincoln Journal Star, Sunday, November 29, 2009. College Laboratory of Natural History 1(6): 177-184. Dyke, S. 2000. Freshwater mussel management in North Call, R. E. 1887. Sixth contribution to a knowledge of the Dakota. Central Plains Archeology: 8(1): 99-101. fresh-water Mollusca of Kansas. Bulletin of the Washburn Edwards, G. 2010. Wyoming Game and Fish mussel College Laboratory of Natural History 2(8): 11-25. database computer file, personal communication. Canfield, H. L. and A. H. Weibe. 1931. A cursory survey of Ellis, M. M. 1916. Anodonta danielsi Lea in Colorado. The the Blue River system of Nebraska. U. S. Department of Nautilus 29: 116-119. Commerce, Bureau of Fisheries, Economic Circular No. 73. Ellis, M. M. 1931. Some factors affecting the replacement pp. 1-10. of the commercial fresh-water mussels. U. S. Clarke, A. H. 1996. Final report, results of a biological survey Department of Commerce, Bureau of Fisheries. Fishery for Leptodea leptodon (Rafinesque, 1820) in the Missouri Circular No. 7: 1-10. River in southeastern South Dakota. A report prepared for Ellis, M. M. 1937. Erosion silt as a factor in aquatic the U. S. Fish and Wildlife Service (under contract no. environments. Ecology 17: 29-42. 60181-2-1619), Ecosearch, Inc.: 48 pp. Environmental Protection Agency. 2009. Draft 2009 Clausen, M. K. and M. E. Havlik. 1994. A survey of the update aquatic life ambient water quality criteria for unionid mollusks (Mollusca: Bivalvia) of the Elkhorn River ammonia-freshwater. Federal Register 74(249): 69086- Basin, Nebraska. Lincoln, Nebraska, U. S. Fish and 69087. Wildlife Service and Nebraska Game and Parks Fennemen, N. M. 1931. Physiography of Western United Commission: iii + 1-38. States. New York and London, McGraw-Hill Book Cockerell, T. D. A. 1889. Preliminary remarks on the Company: xiii + 534 pp. molluscan fauna of Colorado. Journal of Conchology 6: Freeman, P. W. and K. Perkins. 1992. Survey of Mollusks of 60-65. the Platte River. Final Report. Grand Island, Nebraska, U. Coker, R. E. 1919. Fresh-water mussels and mussel S. Fish and Wildlife Service: 37 pp. industries of the United States. Bulletin of the U. S. Freeman, P.W. and K. Perkins. 1997. Survey of Mollusks of Bureau of Fisheries 36 (1917-1918): 13-89, 46 pls. Issued the Niobrara River. Final Report. Grand Island, Nebraska, separately as U. S. Bureau of Fisheries Document 865. U. S. Fish and Wildlife Service: 22 pp. Coker, R. E., A. F. Shira, H. W. Clark, and A. D. Howard. Frest, T. J. 1987. Final Report on Federal Aid Projects Se-1-3 1921. Natural history and propagation of fresh-water and Se-1-4 Mussel Survey of Selected Interior Iowa Streams. mussels. Bulletin of the U. S. Bureau of Fisheries 37 (1919- U. S. Fish and Wildlife Service, Iowa Department of 1920): 77-181, 17 pls. Issued separately as U. S. Bureau Natural Resources, under contract to the University of of Fisheries Document No. 893. Northern Iowa: 216 pp. Coker, R. E. and J. B. Southall. 1915. Mussel resources in Gangloff, M. M. and J. W. Feminella. 2007. Stream channel tributaries of the Upper Missouri River. Bureau of geomorphology influences mussel abundance in Fisheries Document No. 812. Washington Government southern Appalachian streams, U.S.A. Freshwater Printing Office: 17 pp. + 1 plate. Biology 52: 64-74. Conners, D. E. and M. C. Black. 2004. Evaluation of Gangloff, M. M. and D. L. Gustafson. 2000. The freshwater lethality and genotoxicity in the freshwater mussel mussels (Bivalvia: Unionoida) of Montana. Central Plains Utterbackia imbecillis (Bivalvia:Unionidae) exposed singly Archeology 8(1): 121-130. and in combination to chemicals used in lawn care. Grier, R. 1983. River portraits: The Elkhorn. NebraskaLand Archives of Environmental Contamination and Toxicology Magazine 61(1): 66-71. 46(3): 362-371. Haag, W. R., R. S. Butler, and P. D. Hartfield. 1995. An Cordeiro, J.R. 1999. Distribution and habitat of fresh-water extraordinary reproductive strategy in freshwater mussels (Bivalvia: Unionoida: Unionidae) in Colorado. bivalves: prey mimicry to facilitate larval dispersal. Natural History Inventory of Colorado 19: 1-56. Freshwater Biology 34: 471-476.

24 2011 Transactions of the Nebraska Academy of Sciences 32, 1–46 Freshwater Mussels of Nebraska Havlik, M. E. 1980. The historic and present distribution of Hoke, E. 2000b. A critical review of the unionoid mollusks the endangered naiad mollusk Lampsilis higginsi (Lea, reported for Nebraska by Samuel Aughey (1877). 1857). Bulletin of the American Malacological Union, Inc, Central Plains Archeology 8(1): 35-47. pp 9-12. Hoke, E. 2003. Investigations on the distributions of freshwater Havlik, M. E. and L. L. Marking. 1987. Effects of mussels in the Missouri River reservoirs of South Dakota. contaminants on naiad mollusks (Unionidae): A review. Final Report to South Dakota Game, Fish and Parks Resource Publication 164, U.S. Fish and Wildlife Department. Pierre, South Dakota Service, Washington, DC. Hoke, E. 2004. The freshwater mussels (Mollusca: Bivalvia: Hayden, F. V. 1862. On the geology and natural history of Unionidae) of the Little Blue River Drainage of the Upper Missouri. Transactions of the American northeastern Kansas and southeastern Nebraska. Philosophical Society 12: 1-218. Transactions of the Nebraska Academy of Sciences 29: 7-24. Henderson, J. 1920. Changes in western molluscan faunas. Hoke, E. 2005a. The freshwater mussels (Mollusca: Bivalvia: The Nautilus 33(3): 103-105. Unionidae) of northern Nebraska: The Missouri, Henderson, J. 1924. Mollusca of Colorado, Utah, Montana, Niobrara, and White River basins. American Idaho and Wyoming. The University of Colorado Studies Malacological Bulletin 20: 27-35. 13: 65-223. Hoke, E. 2005b. The unionid mussels (Mollusca: Bivalvia: Henderson, J. 1927. Some South Dakota mollusca. The Unionidae) of the Big Blue River Basin of northeastern Nautilus 51: 19-20. Kansas and southeastern Nebraska. Transactions of the Henderson, J. 1936. Mollusca of Colorado, Utah, Montana, Nebraska Academy of Sciences 30: 33-57. Idaho, and Wyoming. The University of Colorado Studies Hoke, E. 2005c. The unionid mussels (Mollusca: Bivalvia: 23: 81-145. Unionidae) of the Missouri River floodplain in Hoffman, R. 1983a. River portraits: The Frenchman. southwestern Iowa and northwestern Missouri. Journal NebraskaLand Magazine 61(1): 16-21. of the Iowa Academy of Science 112(3-4): 62-65. Hoffman, R. 1983b. River portraits: The Republican. Hoke, E. 2009. The freshwater mussels (Mollusca: Bivalvia: NebraskaLand Magazine 61(1): 58-65. Unionidae) of the channelized Missouri River. Journal of Hoke, E. 1979. Wyoming Mussel Distributions as Revealed by the Iowa Academy of Science 116(1-4): 36-43. Survey Activities Conducted During the Summer of 1978. Holland-Bartels, L. E. 1990. Physical factors and their Report submitted to the Wyoming Game and Fish influence on the mussel fauna of a main channel border Department: ii + 1-7. habitat of the upper Mississippi River. Journal of the Hoke, E. 1983. Unionid mollusks of the Missouri River on North American Benthological Society 9: 327-335. the Nebraska border. American Malacological Bulletin 1: Howells, R. G., R. W. Neck and H. D. Murray. 1996. 71-74. Freshwater Mussels of Texas. Austin, Texas Parks and Hoke, E. 1994a. An initial survey of the unionid mollusks Wildlife Department: v + 218 pp. of the system in Nebraska. Triannual Huntoon, P. W. 1974. Predicted Water-Level Declines for Unionid Report 5: 3. Alternative Groundwater Developments in the Upper Big Hoke, E. 1994b. A survey and analysis of the unionid Blue River Basin, Nebraska. Conservation and Survey mollusks of the Elkhorn River Basin, Nebraska. Division, Institute of Agriculture and Natural Transactions of the Nebraska Academy of Sciences 21: 31-54. Resources, Resource Report No. 6. Lincoln, University Hoke, E. 1995. A survey and analysis of the unionid of Nebraska – Lincoln: viii + 106 pp. mollusks of the Platte rivers of Nebraska and their Jacobson, P. J., R. J. Neves, D. S. Cherry, and J. L. Farris. minor tributaries. Transactions of the Nebraska Academy 1997. Sensitivity of glochidial stages of freshwater mussels (Bivalvia:: Unionidae) to copper. Environmental of Sciences 22: 49-72. Toxicology and Chemistry 16(11): 2384-2392. Hoke, E. 1996. The unionid mollusks of the Big and Little Keyes, C. R. 1888. An annotated catalogue of the mollusca Nemaha River Basins of southeastern Nebraska and of Iowa. Bulletin of the Essex Institute 20(4-6): 61-83. northeastern Kansas. Transactions of the Nebraska Kraemer, L. R. 1970. The mantle flap in three species of Academy of Sciences 23: 37-57. Lampsilis (Pelcypoda:Unionidae). Malacologia 10(1): 225- Hoke, E. 1997a. Confirmation of the former occurrence of 282. the federally endangered unionid Quadrula fragosa Lea, I. 1858. [Remarks on the Unionidae of Nebraska (Conrad, 1835) in Kansas. Triannual Unionid Report 13: Territory, etc. Minutes of the March 23, 1858 meeting]. 42. Proceedings of the Academy of Natural Sciences of Hoke, E. 1997b. The unionid mollusks of the upper Kansas Philadelphia 10: 13-14. Basin of northwestern Kansas and southwestern Liechti, P. M. and D. G. Huggins. 1977. Unionacean Nebraska. Transactions of the Nebraska Academy of mussels of Kansas. Technical Publications of the State Sciences 24: 35-62. Biological Survey of Kansas 4: 17-30. Lingle, K. L. 1992. Habitat and Microhabitat Preferences of Hoke, E. 2000a. The scaleshell Leptodea leptodon Adult Freshwater Mussels (Mollusca: Bivalvia: Unionidae) (Rafinesque, 1820) in the Missouri River. Triannual of the Platte River, Nebraska. M. S. Thesis, University of Unionid Report 19: 9. Nebraska at Kearney: 143 pp.

2011 Transactions of the Nebraska Academy of Sciences 32, 1–46 25 E. Hoke Mack, A., J. Weir, and J. Sharpe. 1996a. Registered Irrigation Pierce, D. 1983. Exploring Missouri River Country. Jefferson Wells in Nebraska – Summer 1995. Conservation and City, Missouri Department of Natural Resources, Survey Division, Institute of Agriculture and Natural Division of Parks and Historic Preservation: 276 pp. Resources, Lincoln, University of Nebraska – Lincoln: 1 Popenoe, A. E. 1885. List of unionidae collected in Kansas page rivers with localities. Transactions of the Kansas Academy Mack, A., J. Weir, and J. Sharpe. 1996b. Groundwater-Level of Sciences 9: 78-79. Changes in Nebraska, Predevelopment to Spring 1994. Prophet, C. W. 1967. River pollution by feedlot runoff. Conservation and Survey Division, Institute of Proceedings of the Academy of Science 48: 207- Agriculture and Natural Resources, Lincoln, University 209. of Nebraska – Lincoln: 1 page. Prophet, C. W. and N. L. Edward. 1973. Benthic Mattes, M. J. 1969. The . Nebraska macroinvertebrate community structure in a Great State Historical Society Publications 25: xix + 583 pp. Plains stream receiving feedlot runoff. American Water McCarraher, D. B. 1977. Nebraska’s Sandhills Lakes. Resources Association, Water Resources Bulletin 9: 583- Nebraska Game and Parks Commission, Lincoln, 589. Nebraska: 67 pp. Rausch, C. G. and R. V. Bovbjerg. 1973. Fauna of the Mead, J. R. 1896. A dying river. Transactions of the Kansas middle Little Sioux River and comparison with upper Academy of Science 14: 111-112. and lower regions. Proceedings of the Iowa Academy of Miller, B. B. and C. W. Hibbard. 1972. Recent Mollusca of Science 80: 111-116. Ellsworth County, Kansas. Sterkiana 46: 11-14. Reigle, J. J. Jr. 1967. An occurrence of Anodonta (Mollusca: Missouri Department of Conservation. 2001. Zebra Pelecypoda) in deep water. American Midland Naturalist, mussels found near Kansas City. Missouri 78: 530-531. Conservationist 62(7): 31. Roedel, M. D. 1990. Unionid molluscs in the Big Bend Mohlman, M. 1993. 1935 Republican River flood killed reach of the Platte River, Nebraska. Prairie Naturalist 110, caused $100 million in damages in today’s dollars. 22(1): 27-32. Pp. 58-59. In: Flowerday, C. A. (ed). 1993. Flat Water: A Sayre, W. W. and J. F. Kennedy. 1978. Degradation and and Its Water. Resources Report No. Aggradation of the Missouri River. Proceedings of a 12, Conservation and Survey Division, Institute of Workshop Held in Omaha, Nebraska, 23-25 January Agriculture and Natural Resources, Lincoln, University 1978. Iowa City, Iowa Institute of Hydraulic Research of Nebraska – Lincoln: vi + 292 pp. Report No. 215, University of Iowa: 61 pp. Moulton, G. E. 2003. An American Epic of Discovery: The Scammon, R. E. 1906. The Unionidae of Kansas. Part I. Lewis and Clark Journals. Lincoln, University of An illustrated catalogue of the Kansas Unionidae. The Nebraska Press: i-lxii + 413 pp. Kansas University Science Bulletin, 3(9): 279-373, plates Murray, H. D. and A. B. Leonard. 1962. Handbook of the 52-86. unionid mussels of Kansas. University of Kansas Schainost, S. C. 2003. A live collection of a pistolgrip from Museum of Natural History, Miscellaneous Publication, No. Nebraska. The Prairie Naturalist, 35(4): 277-280. 28: 1-184. Schneiders, R. K. 1999. Unruly river: two centuries of change Oesch, R. D. 1995. Missouri naiades: A Guide to the Mussels along the Missouri. Lawrence, University of Kansas of Missouri. Jefferson City, Missouri Department of Press: 314 pp. Conservation: viii + 271 pp. Schuster, G. A. and M. B. Dubois 1979. Additional new Over, W. H. 1915. Mollusca of South Dakota. The Nautilus records of freshwater mussels (Bivalvia: Unionidae) 29: 79-81 and 90-95. from Kansas. Technical publications of the State Biological Over, W. H. 1928. Additional records of South Dakota Survey of Kansas 8: 1-11. mollusca. The Nautilus 61(3): 92-93. Shearer, J., D. Backlund and S. K. Wilson. 2005. Freshwater Over, W. H. 1942. Mollusca of South Dakota. University of Mussel Survey of the 39-Mile District – Missouri National South Dakota. Natural History Studies 5: 1-11. Recreational River, South Dakota and Nebraska. GFP Parmalee, P. W. and A. E. Bogan. 1998. The Freshwater Report 2005-08. South Dakota Department of Game, Mussels of . Knoxville, University of Tennessee Fish and Parks: 15 pp. Press: xii + 328 pp. Sheffield, L. F. 1993a. Technology. pp. 87-106. In: Perkins, K. and D. C. Backlund. 2000. Freshwater Mussels of Flowerday, C. A. (ed). 1993. Flat Water: A History of the Missouri National Recreational River Below Gavins Nebraska and Its Water. Resources Report No. 12, Lincoln, Point Dam, South Dakota and Nebraska. South Dakota Conservation and Survey Division, Institute of Game, Fish and Parks Report 2000-1: 23 pp. Agriculture and Natural Resources, University of Perkins, K. and D. C. Backlund. 2003. A survey for winged Nebraska – Lincoln: vi + 292 pp. mapleleaf (Quadrula fragosa) and Scaleshell (Leptodea Sheffield, L. F. 1993b. The ‘70s boom meant well leptodon) in the James River, South Dakota. GFP Report installations skyrocketed; the ‘80s bust saw a well- 2003-17: 21 pp. drilling downturn. pp. 127-128. In: Flowerday, C. A. Peyton, M. M. and J. L. Maher. 1995. A survey of mussels (ed). 1993. Flat water: A History of Nebraska and Its (Mollusca: Bivalvia) in the Platte River system and Water. Resources Report No. 12, Lincoln, Conservation associated irrigation and hydropower canal and lake and Survey Division, Institute of Agriculture and systems west of Overton, Nebraska. Transactions of the Natural Resources, University of Nebraska – Lincoln: Nebraska Academy of Sciences 22: 43-48. vi + 292 pp.

26 2011 Transactions of the Nebraska Academy of Sciences 32, 1–46 Freshwater Mussels of Nebraska Sietman, B. E. 2003. Field Guide to the Freshwater Mussels of Utterback, W. I. 1917. Naiadgeography of Missouri. The Minnesota. St. Paul, Minnesota Department of Natural American Midland Naturalist 5: 26-30 + folding chart. Resources: 144 pp. van der Schalie, H. 1966. Hermaphroditism among North Simpson, C. T. 1900. Synopsis of the naiads or pearly American freshwater mussels. Malacologia 5(1): 77-78. fresh-water mussels. Proceedings of the U. S. National van der Schalie. H. 1970. Hermaphroditism among North Museum 22: 501-1044. American freshwater mussels. Malacologia 10(1): 93-112. Skadsen, D. R. 1998. A Report on the Results of a Survey for van der Schalie, H. and F. Lock. 1941. Hermaphrodism in Unionid Mussels on the Upper and Middle Big Sioux River Anodonta grandis, a freshwater mussel. Occasional Papers and Tributaries: Grant, Codington, Hamlin, Brookings, and of the Museum of Zoology, University of Michigan 432: 1- Moody counties, South Dakota. GFP Report 98-02. South 7. Dakota Department of Game, Fish and Parks: iv + 37 Vaughn, C. C., and C. M. Taylor. 1999. Impoundments pp. and the decline of freshwater mussels: A case study of South Dakota Game, Fish & Parks. 2011. Asian clams an gradient. Conservation Biology 13: 912-920. distribution map. Retrieved from the internet 20 July, Walker, B. 1906. A list of shells from Nebraska. The 2011: http://www.gfp.sd.gov/wildlife/nuisance/aqua Nautilus 20(6): 81-83. tic/asian-clam-distribution-map.aspx. Walker, B. 1910. The distribution of Margaritana Starrett, W. C. 1971. A survey of the mussels (Unionacea) of margaritifera (Linn.) in North America. Proceedings of the the Illinois River: a polluted stream. Bulletin of the Malacological Society, London 9(2): 126-145 + 1 map. Illinois Natural History Survey 30(5): 267-403. Watters, G. T. 1992. Unionids, fishes, and the species-area Strayer, D. L. 1999. Use of flow refuges by unionid curve. Journal of Biogeography, 19: 481-490. mussels in rivers. Journal of the North American Watters, G. T. 1996. Small dams as barriers to freshwater Benthological Society 18(4): 468-476. mussels (Bivalvia: Unionoida) and their hosts. Biological Tryon, G. W., Jr. 1868. Notes on Mollusca collected by Dr. Conservation 75: 79-85. F. V. Hayden in Nebraska. American Journal of Watters, G. T. and S. H. O’Dee. 1997. Utterbackia imbecillis Conchology. New Series 4(3): 150-151. goes fishing with nets. Triannual Unionid Report, No 13: Turgeon, D. D., J. F. Quinn, Jr., A. E. Bogan, E. V. Coan, F. 40. G. Hochberg, W. G. Lyons, P. M. Mikkelsen, R. J. Neves, Williams, G. P. 1978. The case of the shrinking channels – C. F. E. Roper, G. Rosenberg, B. Roth, A. Scheltema, F. the North Platte and Platte rivers in Nebraska. U. S. G. Thompson, M. Vecchione, and J. D. Williams. 1998. Geological Survey Circular No. 781: 1-49. Common and Scientific Names of Aquatic Invertebrates From Williams, J. D., M. L. Warren, Jr., K. S. Cummings, J. L. the United States and Canada: Mollusks. Second edition. Harris, and R. J. Neves. 1992. Conservation status of Bethesda, Maryland, American Fisheries Society Special freshwater mussels of the United States and Canada. Publication 26: ix + 526 pp. Fisheries, 18(9): 6-22. Utterback, W. I. 1914. Mussel resources in Missouri. Wilson, W. W. 1910. Fresh-water-mussel hatchery on Department of Commerce, Bureau of Fisheries, Clinch River, Tennessee. House of Representatives, 61st Economic Circular No. 10: 6 pp. Congress, 2nd Session Report No. 1290: 9 pp. Utterback, W. I. 1915-1916. The naiads of Missouri. The American Midland Naturalist 4: 41-53; 97-152; 182-204; 244-273 (1915); 311-327; 339-354; 387-400; 432-464 (1916).

2011 Transactions of the Nebraska Academy of Sciences 32, 1–46 27 E. Hoke Appendix 1 – Nebraska Freshwater Mussel Distributions. Symbols indicate unionid occurrences and generalized data sources as follows: circles = survey occurrences; squares = museum vouchers; and triangles = other published papers. All sources of non-survey data utilized are given by figure in Appendix 2.

Figure 5. Distribution of Actinonaias ligamentina.

Figure 6. Distribution of Amblema plicata.

28 2011 Transactions of the Nebraska Academy of Sciences 32, 1–46 Freshwater Mussels of Nebraska

Figure 7. Distribution of Anodonta suborbiculata.

Figure 8. Distribution of Anodontoides ferussacianus.

2011 Transactions of the Nebraska Academy of Sciences 32, 1–46 29 E. Hoke

Figure 9. Distribution of Arcidens confragosus.

Figure 10. Distribution of Fusconaia flava.

30 2011 Transactions of the Nebraska Academy of Sciences 32, 1–46 Freshwater Mussels of Nebraska

Figure 11. Distribution of Lampsilis cardium.

Figure 12. Distribution of Lampsilis siliquoidea.

2011 Transactions of the Nebraska Academy of Sciences 32, 1–46 31 E. Hoke

Figure 13. Distribution of Lampsilis teres.

Figure 14. Distribution of Lasmigona c. complanata.

32 2011 Transactions of the Nebraska Academy of Sciences 32, 1–46 Freshwater Mussels of Nebraska

Figure 15. Distribution of Lasmigona compressa.

Figure 16. Distribution of Leptodea fragilis.

2011 Transactions of the Nebraska Academy of Sciences 32, 1–46 33 E. Hoke

Figure 17. Distribution of Leptodea leptodon.

Figure 18. Distribution of Ligumia recta.

34 2011 Transactions of the Nebraska Academy of Sciences 32, 1–46 Freshwater Mussels of Nebraska

Figure 19. Distribution of Ligumia subrostrata.

Figure 20. Distribution of Obovaria olivaria.

2011 Transactions of the Nebraska Academy of Sciences 32, 1–46 35 E. Hoke

Figure 21. Distribution of Pleurobema clava.

Figure 22. Distribution of Potamilus alatus.

36 2011 Transactions of the Nebraska Academy of Sciences 32, 1–46 Freshwater Mussels of Nebraska

Figure 23. Distribution of Potamilus ohiensis.

Figure 24. Distribution of Potamilus purpuratus.

2011 Transactions of the Nebraska Academy of Sciences 32, 1–46 37 E. Hoke

Figure 25. Distribution of Pyganodon grandis.

Figure 26. Distribution of Quadrula p. pustulosa.

38 2011 Transactions of the Nebraska Academy of Sciences 32, 1–46 Freshwater Mussels of Nebraska

Figure 27. Distribution of Quadrula quadrula.

Figure 28. Distribution of Strophitus undulatus.

2011 Transactions of the Nebraska Academy of Sciences 32, 1–46 39 E. Hoke

Figure 29. Distribution of Toxolasma parvus.

Figure 30. Distribution of Tritogonia verrucosa.

40 2011 Transactions of the Nebraska Academy of Sciences 32, 1–46 Freshwater Mussels of Nebraska

Figure 31. Distribution of Truncilla donaciformis.

Figure 32. Distribution of Truncilla truncata.

2011 Transactions of the Nebraska Academy of Sciences 32, 1–46 41 E. Hoke

Figure 33. Distribution of Uniomerus tetralasmus.

Figure 34. Distribution of Utterbackia imbecillis.

42 2011 Transactions of the Nebraska Academy of Sciences 32, 1–46 Freshwater Mussels of Nebraska

Figure 35. Distribution of Villosa lienosa.

D

Figure 36. Distributions of Introduced Bivalves. C = Corbicula fluminea and D = Dreissena polymorpha (Pallas, 1771).

2011 Transactions of the Nebraska Academy of Sciences 32, 1–46 43 E. Hoke

Appendix 2 – Sources of Non-Survey Data Utilized in Distribution Maps Note: Literature citations, if any, are presented first and followed by museum vouchers. Designations of museums for records given are indicated as follows: FMNH – Field Museum of Natural History, Chicago, Illinois NMNH – National Museum of Natural History, Washington , D. C. PANS – Philadelphia Academy of Natural Sciences, Philadelphia, Pennsylvania UCMNH – University of Colorado Museum of Natural History, Boulder, Colorado UMMZ – University of Michigan Museum of Zoology, Ann Arbor, Michigan UNSM – University of Nebraska State Museum, Lincoln, Nebraska UNOB – University of Nebraska – Omaha, Department of Biology, Omaha, Nebraska

Figure Non-Survey Sources 5 None. 6 Shearer et al. (2005). Museum vouchers: NMNH No. 512437 (West Point, Nebraska), and 540270 ( Creek at Lincoln, Nebraska); PANS No. 9456 – (Nebraska City); UMMZ No. 99771 – (Weeping Water Creek at Weeping Water, Nebraska). 7 Perkins and Backlund (2000). Museum voucher: UNSM No. 00074.3 – (Missouri River, Boyer Chute, Washington County, Nebraska). 8 Museum voucher: NMNH No. 512240 – (Aowa Creek). 9 Perkins and Backlund (2000). 10 Museum vouchers: NMNH Nos. 539968 & 514912 – (West Point, Nebraska); UMMZ No. 93054 – (Weeping Water Creek, Weeping Water, Nebraska). 11 Clausen and Havlik (1994); Schainost (2003). Museum voucher: NMNH No. 512425 – (Aowa Creek, Ponca, Nebraska). 12 Freeman and Perkins (1992); Perkins and Backlund (2000); Schainost (2003). Museum vouchers: FMNH No. 59326 – (Cambridge, Nebraska); NMNH No. 514994 – (Big Blue River near Crete, Nebraska); UMMZ No. 87234 – (Big Blue River at Crete, Nebraska); UNSM unnumbered – (Weeping Water Creek, Weeping Water, Nebraska). 13 Perkins and Backlund (2000). Museum vouchers: NMNH Nos. 540293 & 540300 – (West Point, Nebraska) and No. 738424 – (Nebraska City, Nebraska); PANS No. 54036 – (Aowa Creek, Ponca, Nebraska). 14 Lingle (1993); Clausen and Havlik (1994); Perkins and Backlund (2000); Schainost (2003); Shearer et al. (2005). Museum vouchers: NMNH No. 477141 – (Aowa Creek, Ponca, Nebraska); UMMZ No. 246766 – (Cambridge, Nebraska); UNSM unnumbered – (Weeping Water Creek, Weeping Water, Nebraska). 15 Tryon (1868). Museum voucher: NMNH No. 477051 – (West Point, Nebraska). 16 Freeman and Perkins (1992); Lingle (1993); Clausen and Havlik (1994); Perkins and Backlund (2000); Schearer et al. (2005). Museum vouchers: UCMNH No. 36775 – (Big Blue River near Barneston, Nebraska); UNSM No. 1991-10-KP3 (Missouri River, Boyer Chute) and unnumbered – (Weeping Water Creek, Weeping Water, Nebraska). 17 None. 18 Schainost (2003). Museum vouchers: PANS No. 42389 – (Falls City, Nebraska); UNSM No. 1158 – (Big Blue River, Crete, Nebraska) and No. 35-1-26-87.5 – (Big Blue River, Seward, Nebraska). 19 Clausen and Havlik (1994). Museum vouchers: NMNH No. 477017 – (Dead Mans Run, Lincoln, Nebraska) and No. 504856 – (West Point, Nebraska); UMMZ No 89630 – (Weeping Water Creek, Weeping Water, Nebraska). 20 Museum voucher: NMNH Nos. 514939 & 540279 – (West Point, Nebraska). 21 None. 22 Freeman and Perkins (1992); Perkins and Backlund (2000); Shearer et al. (2005). Museum Vouchers: NMNH No. 477132 – (Aowa Creek, Ponca, Nebraska) and No. 521412 – (Papillion Creek, Douglas Co., Nebraska); UNSM – (Calamus Reservoir, Nebraska). 23 Lingle (1993); Peyton and Maher (1995)1 – (Lake Maloney); Perkins and Backlund (2000); Schainost (2003); Schearer et al. (2005). Museum vouchers: UCMNH No. 40927 – (Johnson Lake); UMMZ No. 7663 – (Crystal Lake, Nebraska); UNSM No. 00076.1 – (Missouri River, Boyer Chute) and unnumbered - (Weeping Water Creek, Weeping Water, Nebraska). 24 Museum voucher: UNSM No. 30-1-26-87 – (Papillion, Nebraska). 25 Baxa (1981), Freeman and Perkins (1992), Perkins and Backlund (2000); Schainost (2003); Shearer et al. (2005). Museum vouchers: NMNH No. 539910 – (Aowa Creek, Ponca, Nebraska); PANS No. 131310 – (Salt Creek, Lincoln, Nebraska); UNSM No. 00075.1 – (Missouri River, Boyer Chute) and unnumbered – (Weeping Water Creek, Weeping Water, Nebraska). 26 Clausen and Havlik (1994). 27 Freeman and Perkins (1992); Lingle (1993); Clausen and Havlik (1994); Perkins and Backlund (2000); Schearer et al. (2005). Museum vouchers: NMNH Nos. 514990 & 515020 – (West Point, Nebraska); UNSM unnumbered – (Weeping Water Creek, Weeping Water, Nebraska). 28 Freeman and Perkins (1997); Peyton and Maher (1995)1. Museum vouchers: PANS No. 56710 – (Nebraska City, Nebraska). 29 Museum vouchers: NMNH No 477094 – (West Point, Nebraska); PANS No. 42149 – (Falls City, Nebraska); UCMNH – (Johnson Lake). 30 Schainost (2003). Museum voucher: UNSM 248-8-1-20 – (Little Nemaha River, Nebraska); UNOB unnumbered – (Missouri River).

44 2011 Transactions of the Nebraska Academy of Sciences 32, 1–46 Freshwater Mussels of Nebraska Appendix 2 – Sources of Non-Survey Data Utilized in Distribution Maps, continued.

Figure Non-Survey Sources 31 Perkins and Backlund (2000). Museum vouchers: NMNH No. 510881 – (West Point, Nebraska); PANS No. 56630 – (Falls City, Nebraska); UNSM No. 1285 – (West Point, Nebraska). 32 Perkins and Backlund (2000). 33 Roedel (1990): Lingle (1992). Museum vouchers: NMNH No. 504853 – (Big Blue River, Milford, Nebraska); UNSM unnumbered – (Weeping Water Creek, Weeping Water, Nebraska). 34 Baxa (1981); Roedel (1990); Clausen and Havlik (1994); Peyton and Maher (1995)1; Schearer et al. (2005). Museum vouchers: NMNH No. 519293 – (Oak Creek, Lincoln, Nebraska); UNSM 1991-12-KP3 – (Missouri River chute). 35 Tryon (1868). Museum voucher: PANS No 56468 – (Falls City, Nebraska). 36 C = Corbicula fluminea South Dakota Game, Fish and Parks (2011); D = Dreissena polymorpha (Pallas, 1771) Missouri Department of Conservation (2001), Duggan (2009b). 37 A = Alasmidonta marginata UNSM.No. 27-1-26-87 (Nemaha); E = Ellipsaria lineolata Canfield and Wiebe (1931) – Big Blue River at Crete, Nebraska; and L = Lampilis higginsii Shearer et al. (2005), NMNH No. 512459 – (West Point, Nebraska).

1Exact locale given by Peyton to author via E-mail communication.

Appendix 3 – Unionoid Mollusks and Distributions Reported for Nebraska by Aughey (1877). Basin Species1 Blue Elkhorn Nemaha Republican Bow Other Actinonaias ligamentina X – X – X Tomaz Actinonaias pectorosa (Conrad, 1834) X X X – – – Alasmidonta marginata – X X – X – Amblema plicata – – X – – – Anodonta suborbiculata X X – – – – Anodontoides ferussacianus – – X – – Middle Cumberlandia monodonta (Say, 1829) X X – – – – Elliptio complanata (Lightfoot, 1786) X X X X – Papillion Elliptio congaraea (Lea, 1831) – – X – – – Elliptio crassidens (Lamarck, 1819) X – – – – – Elliptio dilatata X – X – – – Elliptio spinosa (Lea, 1836) – – – – X – Epioblasma flexuosa (Rafinesque, 1820) X X – – – – Epioblasma o. obliquata (Rafinesque, 1820) – – X – – – Epioblasma personata (Say, 1829) X – – – – – Epioblasma torulosa gubernaculum (Reeve, 1865) – – – X – – Epioblasma t. torulosa (Rafinesque, 1820) – – X – – – Epioblasma triquetra (Rafinesque, 1820) X – X – – – Fusconaia flava X X X X X X Glebula rotundata (Lamarck, 1819) – – X – – – Lampsilis cardium X – X – – – Lampsilis fasciola Rafinesque, 1820 X – X – – – Lampsilis higginsii (Lea, 1857) – – X – – – Lampsilis ovata (Say, 1817) X X – – – – Lampsilis siliquoidea X – X – X Oak Lampsilis teres X X X – – – Lasmigona c. complanata – – X – – – Lasmigona compressa – – X – – – Leptodea fragilis X X – – X – Leptodea leptodon – – X – – – (Say, 1817) X – X – – – Ligumia recta – – X – – – Ligumia subrostrata X X X X – – Megalonaias nervosa (Rafinesque, 1820) – – X – – – Obliquaria reflexa (Rafinesque, 1820) X X X – – Papillion Obovaria subrotunda (Rafinesque, 1820) – – X – – –

2011 Transactions of the Nebraska Academy of Sciences 32, 1–46 45 E. Hoke Appendix 3 – Unionoid Mollusks and Distributions Reported for Nebraska by Aughey (1877), continued.

Basin Species1 Blue Elkhorn Nemaha Republican Bow Other Pleurobema clava X – X – – – Pleurobema sintoxia (Rafinesque, 1820) X X X – – Papillion, Logan Potamilus alatus X X X – – – Potamilus capax (Green, 1832) X X – – – – Potamilus ohiensis X – X – – – Potamilus purpuratus – – X – – – Pyganodon grandis X X X X X Iowa, Elk, Oak Quadrula c. cylindrica (Say, 1817) X – X – – Logan Quadrula fragosa (Conrad, 1835) X – – – X – Quadrula metanevra (Rafinesque, 1820) – X X – – – Quadrula p. pustulosa – – – – X Iowa Quadrula quadrula X X X – – – Strophitus undulatus X – X – – – Toxolasma parvus X X – – – – Tritogonia verrucosa X – X – – – Truncilla donaciformis X – – – – – Truncilla truncata – – X – – – Uniomerus tetralasmus – – X – – – Utterbackia imbecillis – – X – – – Venustaconcha ellipsiformis (Conrad, 1836) – – – – X – Villosa lienosa X – X – – – Total Species by Basin 34 19 42 5 10 10

1Original names converted to current nomenclature as given in Turgeon et al. (1998).

46 2011 Transactions of the Nebraska Academy of Sciences 32, 1–46