Occurrence and distribution of freshwater mussels in small streams of Tippecanoe County, Indiana.

ABSTRACT. A mussel survey was conducted at 52 sites in 12 stream systems within Tippecanoe County, Indiana. The study did not include the Wabash River, the Tippecanoe River, or the Middle Fork of Wildcat Creek. Evidence of 28 mussel species was found during the survey; 17 species were found live. Of all live mussels, 58% were Lampilis siliquoidea (fatmucket). Mussel species richness in each stream system was significantly correlated with watershed area and fish species richness. However, the presence of potential host fish species did not entirely explain the mussel distribution.

Keywords: Headwater streams, mussel distribution, host fish

Surveys of freshwater mussels (unionids) in North America have documented declines of mussel species diversity and reduced distributional ranges (Meyer 1968; Dineen 1971; Cummings et al. 1992). Of 297 native freshwater mussel species in the United States and Canada, 71.7% are considered endangered, threatened, or of special concern (Williams et al. 1993). Changes in mussel populations may be a good indicator of stresses on the stream ecosystem caused by agriculture, industry, or urbanization (Dineen 1971).

The unionid's life cycle has the larval stage, the glochidium, parasitic on a fish host. The glochidium undergoes transformation into a juvenile mussel during this parasitic phase. The host-parasite relationship is specific in that only certain species of fish may serve as glochidial hosts for any given mussel species. When transformation is complete, the juvenile mussel detaches from the fish and begins life as an independent organism (McMahon 1991). The movement of fish bearing glochidia is the main mechanism of unionid dispersal. Whether a mussel can then survive in any given location therefore depends on immediate environmental conditions and chance events such as droughts, floods, and exposure to pollutants (Watters 1992).

Small streams are generally under-represented in mussel status reports because they are not included in most stream surveys and mussel populations are usually not assessed as part of most stream faunistic surveys which usually focus on fish and/or aquatic insects. Recent regional mussel surveys which did include small streams include the Sangamon River Basin, Illinois (Schanzle & Cummings 1991), the Big Darby Creek system, Ohio (Watters 1994) and a few selected tributaries of the Tippecanoe River, Indiana (Ecological Specialists, Inc. 1993).

Factors affecting whether or not a small stream will support mussels include presence of host fish species, size of watershed area, and suitability of habitat. Mussels thought to be typical headwater species include Anodontoides ferussacianus, Alasmidonta viridis and Lasmigona compressa (Cummings & Mayer 1992); but because of the lack of small stream mussel survey data, it is not known to what extent these streams might support additional species.

Tippecanoe County, located in west central Indiana, includes a variety of small streams as well as the confluence of the Tippecanoe with the Wabash River. Land use in Tippecanoe is primarily agricultural but is undergoing rapid urbanization. The Wabash River flows through the county from northeast to southwest; and all streams in the county, including the Tippecanoe River, are tributaries of the Wabash. The Tippecanoe and Wabash River watersheds contain a high diversity of unionid fauna (Goodrich & van der Schalie 1944; Cummings & Berlocher 1990). Recent mussel surveys in the middle Wabash drainage include the Wabash and Tippecanoe Rivers (Cummings et al. 1992), the Tippecanoe River (Ecological Specialists, Inc. 1993) and the Middle Fork of Wildcat Creek (Henschen 1990), and the present study did not include these waterways. Tippecanoe County is an especially good location to address these issues because of recent surveys of fish and large river mussels, and rapid changes in land use.

There are many potential variables controlling the occurrence and distribution of mussels, including water quality issues and physical habitat suitability. However, fundamental to the perpetuation of mussel life is the presence of host fish. The size of the watershed can influence fish populations and, therefore, mussel populations (Watters 1993). Because of this unique host-parasite relationship, the discussion of factors affecting mussel distribution will examine the effects of watershed size and fish diversity, and compare mussel distributions with host fish distributions.

The objective of this study was to determine the occurrence and distribution of mussels in 12 small stream systems. This distribution was correlated to the watershed areas and fish species richness of the stream systems to evaluate the relationship of these factors to mussel species richness. Host fish distributions were compared to the presence or absence of mussels in each stream system to determine the extent to which host fish availability limits mussel distribution. This study will serve as a baseline for future work with small stream mussel populations.

METHODS

Description of study area.--A mussel survey was conducted at 52 sites in 12 watersheds in Tippecanoe County, Indiana (Fig. 1) in June-August 1995. These same sites were surveyed for fish in 1994 (Fisher et al. 1998). The characteristics of streams included in the study varied tremendously. Included were channelized agricultural ditches, unaltered small streams with forested riparian corridors, and a designated scenic waterway (Wildcat Creek) of moderate size. Stream orders at the sites varied from second (Site 7) to fifth (Site 34). The smallest stream was Bridge Creek, with a total watershed area of 16 [km.sup.2] and the largest was Wildcat Creek, with a total watershed area of 2085 [km.sup.2] (Hoggatt 1975).

Survey methodology.--Stream sites were surveyed once each by walking for a length of stream bed covering at least three rifflepool sequences. Search efforts varied from a minimum of 2 person-hours at the smallest sites to at least 10 person-hours at the largest sites on Wildcat Creek. All types of habitat were visually searched, including banks, gravel bars, pools and riffles. Visible trails in the substrate were searched by hand digging to locate burrowed mussels. At each site, the number and species of live mussels and mussel shells were recorded. Specimens were classified as live, fresh shell or weathered shell. Fresh shells were categorized as having the hinge ligament unbroken or the periostracum largely intact. Live mussels were identified in the field and returned to the stream, with voucher specimens being collected from dead shells only. Identifications were made using the taxonomic references of Oesch (1984), Watters (1995) and Cummings & Mayer (1992), and by examination of specimens housed in the Indiana State Museum. Voucher specimens are located at Purdue University.

Data analysis.--Information on mussel species distributions was compared with fish species distributions for these sites (Fisher et al. 1998) and host fish species lists (Watters 1995). Regression analyses were done to evaluate the relationships between the number of mussel species versus the log of the watershed size, and between the number of mussel species present by stream system versus number of fish species (Table 1). The regression analyses included Tippecanoe County mussel data from the Wabash and Tippecanoe Rivers (Cummings et al. 1992), but excluded Big Shawnee Creek. Only one site was surveyed on the upstream portion of Big Shawnee Creek; however, the remainder of the stream which continues through Fountain County, Indiana was not surveyed.

RESULTS

Mussel distribution.--Twenty-eight species of mussels (Table 2) were found during the survey; and of these, 219 individuals of 18 species were found alive (Table 3). Three species (Lampsilis siliquoidea, Anodontoides ferussacianus and Pyganodon grandis) were the most common found alive, comprising 72.2% of the total. Uncommon species were Strophitus undulatus, Alasmidonta marginata, Lampsilis teres, and Ligumia recta, each being represented by one live individual.

All stream systems surveyed, except Bridge Creek, showed evidence of unionid life, whether in the form of live individuals or shells. Only weathered shells were found in Indian Creek, Buck Creek, Flint Run (site 10), Dismal Creek (site 29), and Sugar Creek. Flint Run is a tributary of Flint Creek, and Dismal Creek is a tributary of Wea Creek. Only one weathered shell fragment of Anodontoides ferussacianus was found in Indian Creek at site 13, and one weathered valve of Actinonaias ligamentina was found in Buck Creek at site 44.

Of all live mussels found during the study, 58% were Lampsilis siliquoidea. They were found alive at five Wildcat Creek sites, and shells of this mussel were found at all Wildcat Creek sites. They were also found alive in Lauramie, Wea, and Little Pine Creeks.

Anodontoides ferussacianus and Alasmidonta viridis were found in headwater areas during this study. Twenty-one live Anodontoides ferussacianus were found, representing 9.6% of the total live mussels, in Little Pine Creek, Wea Creek, and Moots Creek. Four live Alasmidonta viridis specimens, representing 1.8% of total live mussels, were found by digging with the hands at the end of visible mussel trails in Wea and Big Shawnee Creeks. Thirteen sites on Big Shawnee Creek, Wea Creek, Little Wea Creek, Little Pine Creek, Sugar Creek, South Fork Wildcat Creek and Flint Run yielded either live mussels or shells of Alasmidonta viridis.

Lasmigona compressa were also found in headwater areas. They were found live or as shells at sites in Little Pine Creek, Wea Creek, South Fork Wildcat Creek, Moots Creek, and Sugar Creek. Only two live individuals (sites 4 and 22) were found, representing 0.9% of total live mussels.

Three species found in both smaller streams and in the larger Wildcat Creek system were Pyganodon grandis, Lampsilis cardium and Fusconaia flava. Live Pyganodon grandis represented 9.6% of total live mussels, and were found as shells or live individuals in Little Pine Creek and Wildcat Creek. Lampsilis cardium was found in Wildcat Creek and Wea Creek, including a live mussel at Wea Creek site 19, and at Wildcat Creek sites 34, 36, 39 and 40. Fusconaia flava was found in Wea, Little Pine and Wildcat Creeks, including live individuals at Wea Creek sites 19 and 20.

Evidence of 26 species of mussels was found in the Wildcat Creek system, and of these, nine species were found alive. Species found only in the Wildcat Creek system, whether as live mussels or shells, were Alasmidonta marginata, Amblema plicata, Cyclonaias tuberculata, Elliptio dilatata, Lampsilis teres, Lasmigona complanata, Lasmigona costata, Leptodea fragilis, Ligumia recta, Pleurobema clava, Potamilus alatus, Quadrula pustulosa, Quadrula quadrula, Tritogonia verrucosa and Truncilla truncata. Mussel species that were found either as live individuals or shells only in the downstream portion (sites 34 and 35) of Wildcat Creek were Quadrula quadrula, Leptodea fragilis, Potamilus alatus, and Truncilla truncata. Pleurabema clava and Cyclonalas tuberculata were each represented by one weathered valve in North Fork Wildcat Creek.

Little Pine Creek contained 11 species of mussels, including two species not found in any other stream in the study. These were Uniomerus tetralasmus and the state species of special concern Toxolasma lividus. Toxolasma lividus was found at only one sampling site (Site 3) which had two live specimens and numerous fresh shells. All Little Pine Creek sites in Tippecanoe County supported live mussels except the most upstream site (site 6) and site 7 on the tributary stream Otterbein Ditch in the town of Otterbein, Tippecanoe County, Indiana.

Two species, Toxolasma parvus and Uniomerus tetralasmus, are new Tippecanoe County records. Toxolasma parvus was found in four streams (BowenDitch, Little Pine Creek, Wea Creek, and Wildcat Creek) and Uniomerus tetralasmus in one stream (Little Pine Creek).

Effects of watershed area and host fish.--The number of species per watershed was significantly correlated to the drainage area ([r.sup.2] = 0.91, P < 0.01) (Fig. 2). Correlation of the number of mussel species to the number of fish species was also highly significant ([r.sub.2] = 0.80, P < 0.01) (Fig. 3).

Comparisons were made by stream system for occurrences of mussels and host fish. For each mussel species found, host fish were documented for that stream system in all but two instances (Bowen Ditch and Buck Creek); however, host fish distributions exceeded mussel distributions.

DISCUSSION

Mussel distribution.--The small streams of Tippecanoe County are home to a diverse and widely-distributed mussel fauna, as demonstrated by 219 live individuals of 18 species found. However, the fact that only weathered shells were found in five streams implies that mussels existed in those streams in the past, but are unable to do so now.

Lampsilis Siliquoidea is one of the most common mussels in Indiana (Goodrich & van der Schalie 1944). In a survey of the Eel River in Indiana, Lampsilis siliquoidea occurred at all sites where live mussels were found (Henschen 1987). Even this nearly ubiquitous species may have its limits of tolerance to habitat disturbance. Lampsilis siliquoidea appears to have declined in the Sangamon River drainage of Illinois, a watershed impacted by channelization, impoundment, and agricultural, industrial and municipal runoff (Schanzle & Cummings 1991). Because of the lack of historical data for the small streams in the present study, it is not known if a similar decline is occurring in Tippecanoe County.

Several species of mussels are considered to be typical of headwater streams: Anodontoides ferussacianus, Alasmidonta viridis, and Lasmigona compressa (Cummings et al. 1992). Anodontoides ferussacianus was common and widespread in the present study. Schanzle & Cummings (1991) found Anodontoides ferussacianus in the upstream portions of the Sangamon River and its tributaries in sufficient numbers to constitute 2% of their total sample; and Ecological Specialists, Inc. (1993) called it one of the most common species collected in tributaries. Ecological Specialists, Inc. (1993) found Alasmidonta viridis distributed in tributary streams, although it was rare. Alasmidonta viridis is known to burrow in the substrate (Watters 1995) and may be easily missed. Ecological Specialists, Inc. (1993) also found that the small size of this unionid reduced chances of finding it alive. In the present study Lasmigona compressa individuals were widely scattered and never present in great numbers. Ecological Specialists, Inc. (1 993) found Lasmigona compressa to be rare and scattered in the tributaries of the Tippecance River, as did Schanzle & Cummings (1991) in the tributaries of the Sangamon River. The present study shows that the typical headwater species Alasmidonta viridis and Lasmigona compressa are present in small streams, but their ranges may be underestimated due to difficulties in locating them.

Three species, Pyganodon grandis, Lampsilis cardium, and Fusconala flava were widespread in their distribution. These three species are able to inhabit smaller streams such as Little Pine Creek and Wea Creek, moderate size streams such as Wildcat Creek, and large rivers such as the Wabash or Tippecanoe Rivers (pers. obser.).

Exceptional streams.--The Wildcat Creek system was exceptional in its mussel diversity in that it showed evidence of 26 mussel species. The four species found only in the downstream portion are more typical riverine species that are common in the Wabash River. A troubling observation was that the federally-endangered Pleuroberna clava and the uncommon Cyclonaias tuberculata were found only as weathered shells in the North Fork Wildcat. This is similar to the finding of Henschen (1987) in which the Eel River, a stream with a similar watershed size to Wildcat Creek, yielded only shells of Pleurobema clava and Cyclonaias tuberculata. These species are disappearing from much of their former ranges, and Wildcat Creek may be no exception to this trend.

Little Pine Creek supports 11 mussel species, including the only known Tippecanoe County population of Uniomerus tetralasmus. This species is uncommon (Cummings & Mayer 1992) and was found in only one tributary of the Big Darby Creek system of Ohio (Watters 1994). The state species of special concern Toxolasina lividus individuals in Little Pine Creek are isolated from others of the same species. Previous county records of Toxolasma lividus include one live individual in the Tippecanoe River near the mouth (Cummings et al. 1992). These populations in Little Pine Creek are vulnerable to local extirpation from events such as ditching to facilitate agricultural drainage.

The discovery of two mussel species that are new county records emphasizes the importance of studying small streams. Many of these streams are subject to habitat modification, non-point source pollution, and land-use changes. Without

baseline data on the biota of these streams, we may never know the magnitude of these impacts.

Effects of watershed area and fish diversity.--The effect of watershed area shows increasing unionid diversity with greater watershed area. The stream with the smallest watershed area, Bridge Creek (16 [km.sup.2]) is probably too small to support mussels. Bowen Ditch, with a watershed area of 20 [km.sup.2], yielded one mussel species. The habitat quality of Bridge Creek was as least as good as that of Bowen Ditch and both supported nine fish species, implying that the minimum watershed size needed for mussels is approximately 20 [km.sup.2]. Unionid diversity is not solely a consequence of the drainage area, but is also related to the fish diversity (Watters 1992). In small systems, the number of unionids is related to the drainage area, while in larger systems unionid diversity is related to both drainage area and fish diversity (Watters 1992).

Regression between number of mussel species and number of fish species is a linear function ([r.sup.2] = 0.80). A similar analysis by Watters (1993) gave an [r.sup.2] of 0.92, indicating the species numbers of fishes and unionids are highly correlated. The ratio of fish diversity to unionid diversity is essentially a constant, and this ratio may be used to predict an expected unionid diversity (Watters 1993). Deviations from expected unionid diversity based on fish diversity may be attributed to several causes such as fish mobility, presence of exotic fish species, and the persistence of unionid shells many years after the death of the animal (Watters 1992).

Comparison with host fish distributions.--Host fish were documented for observed mussels in all but two instances. This apparent anomaly is undoubtedly a result of the transient nature of fish communities at any given location. No dams that would limit fish movement are present on any of the streams.

For some mussel species, distributional ranges corresponded closely with those of known host fish. Examples include Potamilus alatus, Leptodea fragilis and Truncilla truncata inhabiting the downstream portion of Wildcat Creek along with their host fish, Aplodinotus grunn lens (freshwater drum). Another example is the host fish for Uniomerus tetralasmus, Notemigonus crysoleucas (golden shiner) that was found in only Little Pine Creek and in the Wabash River during a Tippecanoe County fish survey (Fisher et al. 1998); and the only known Tippecanoe County population of Uniomerus tetralasmus is in Little Pine Creek. For most other mussel species, the ranges of the host fish greatly exceeded the ranges of the mussels. Hosts for Toxolasma lividus are Lepomis cyanellus (green sunfish) and Lepomis megalotis (long ear sunfish) which are widely distributed throughout the county, but this mussel was limited to one site. This concurs with the findings of Bauer et al. (1991) that the distribution pattern of hosts does no t explain the distribution pattern of the mussels. The role of host fish in mussel distribution is an essential one, but other environmental factors limit whether a particular species can survive past the postparasitic stage.

In some cases where the habitat preferences of a mussel species is known, it may be concluded that this, rather than the presence of host fish, is the determinant for mussel success. For example, Alasmidonta marginata usually occurs in clear flowing streams of moderate size (Watters 1995). Alasmidonta marginata was present only in Wildcat Creek, which also contains the host species Ambloplites rupestris (rock bass), Moxostoma macrolepidotum (shorthead redhorse), Hypentelium nigricans (northern hogsucker), and Catostomus commersoni (white sucker). However, these fish were widely-distributed throughout the county. Strayer (1983) states that in addition to stream size, surface geology is also a factor in defining mussel species habitats, and that hydrological variability associated with surface geology is probably an important factor in determining unionid distributions.

CONCLUSIONS

The distribution of mussels in Tippecanoe [T1][T2]County indicated a total of 28 species in 12 watersheds. Of these, some species are typical of headwater areas, others inhabit moderate size streams such as Wildcat Creek, and others are widely-distributed throughout the county. The mussel species richness was significantly correlated with fish species richness, but the pattern of host fish distribution did not entirely explain the patterns of mussel distribution. Since mussels are not routinely included in small stream water quality surveys, many of the factors influencing mussel distribution, such as habitat requirements, are not well known. Because of the recent decline in mussel populations, this merits further study.

ACKNOWLEDGMENTS

The authors would like to thank Laurie Hatton and Brant Fisher for assistance with field work. We would also like to thank Dr. G. Thomas Watters of The Ohio State University and Ron Richards of the Indiana State Museum for taxonomic assistance. A review of an earlier version of this manuscript by Dr. Jon Harbor was greatly appreciated.

LITERATURE CITED

Bauer, G., S. Hochwald, & W. Silkenat. 1991. Spatial distribution of freshwater mussels: The role of host fish and metabolic rate. Freshwater Biology 26:377-386.

Cummings, K.S. & J.M.K. Berlocher. 1990. The naiades or freshwater mussels (Bivalvia: Unionidae) of the Tippecanoe River, Indiana. Malacological Review 23:83-98.

Cummings, K.S & C.A. Mayer. 1992. Field Guide To Freshwater Mussels Of The Midwest. Illinois Natural History Survey Manual 5, Champaign, Illinois. 194 pp.

Cummings, K.S, C.A. Mayer & L.M. Page. 1992. Survey Of The Freshwater Mussels (Mollusca: Unionidae) Of The Wabash River Drainage -- Final Report. Illinois Natural History Survey, Champaign, Illinois. 201 pp.

Dineen, C.F. 1971. Changes in the molluscan fauna of the Saint Joseph River, Indiana, between 1959 and 1970. Proceedings of the Indiana Academy of Science 80:189-195.

Ecological Specialists, Inc. 1993. Mussel Habitat Suitability And Impact Analysis Of The Tippecanoe River. U.S. Fish and Wildlife Service Endangered Species Program E-l-6 (Study 17). 102 pp.

Fisher, B.E., S.P. Wente, T.P. Simon & A. Spacie. 1998. The fishes of Tippecanoe County, Indiana. Proceedings of the Indiana Academy of Science 107: 151-166.

Goodrich, C. & H. van der Schalie. 1944. A revision of the mollusca of Indiana. American Midland Naturalist 32:257-326.

Henschen, M. 1987. The Freshwater Mussels (Unionidae) Of The Eel River In Northern Indiana. Indiana Department of Natural Resources Non-game Program, Indianapolis, Indiana, 35 pp.

Henschen, M. 1990. The Freshwater Mussels Of The Middle Fork Wildcat Creek, Indiana. Indiana Department of Natural Resources Non-game Program, Indianapolis, Indiana. 16 pp.

Hoggatt, R.E. 1975. Drainage Areas Of Indiana Streams. U.S. Geological Survey, Water Resources Division, Indianapolis, Indiana. 231 pp.

McMahon, R.F. 1991. Mollusca: Bivalvia. Pp. 315-399, In Ecology And Classification Of North American Freshwater Invertebrates. (J.H. Thorp & A.P. Covich, eds.). Academic Press, Inc., San Diego. 911 pp.

Meyer, E.R. 1968. The Distribution And Abundance Of Freshwater Mussels Of The Family Unionidae (Pelecypoda) Of The Wabash, White, And East Fork Of The White Rivers Of Indiana. Indiana Department Natural Resources, Division of Fish and Game, Indianapolis, Indiana. 68 pp.

Oesch, R.D. 1984. Missouri Naiades: A Guide To The Mussels Of Missouri. Missouri Dept. of Conservation. Jefferson City, Missouri. 270 pp.

Schanzle, R.W. & K.S. Cummings. 1991. A Survey Of The Freshwater Mussels (Bivalvia: Unionidae) Of The Sangamon River Basis, Illinois. Illinois Natural History Survey Biological Notes 137. 25 pp.

Strayer, D. 1983. The effects of surface geology and stream size on freshwater mussel (Bivalvia, Unionidae) distribution in southeastern Michigan, USA. Freshwater Biology 13:253-264.

Watters, G.T. 1992. Unionids, fishes, and the species-area curve. Journal of Biogeography 19: 481-490.

Watters, G.T. 1993. Mussel diversity as a function of drainage area and fish diversity: Management implications. Pp. 113-116, In Conservation And Management Of Freshwater Mussels. Proceedings of a Upper Mississippi River Conservation Committee Symposium. (K.S. Cummings, A.C. Buchanan & L.M. Koch, eds.). St. Louis, Missouri, 189 pp.

Watters, G.T. 1994. Unionidae of the Big Darby Creek system in central Ohio, USA. Malacological Review 27:99-107.

Watters, G.T. 1995. A Guide To The Freshwater Mussels Of Ohio. (revised 3rd edition). Ohio Department of Natural Resources Division of Wildlife, Columbus, Ohio. 119 pp.

Williams, J.D., M.L.J. Warren, K.S. Cummings, J.L. Harris & R.J. Neves. 1993. Conservation status of freshwater mussels of the United States and Canada. Fisheries 18:6-22.

[Figure 2 omitted]

[Figure 3 omitted]

Table 1

Mussel and fish species richness in relation to watershed areas by
stream system. Mussel species include live, fresh shells and weathered
shells. Watershed areas are reported to the mouth of stream, except for
the Wabash River, which shows the drainage are to Lafayette, Indiana.
Superscripts represent: (a)Hoggatt 1975; (b)Fisher et al. 1998;
(c)Cummings et al. 1992.

                         Water shed     Number of   Number of
                            area         mussel       fish
 Stream system        ([km.sup.2]) (a)   species   species (b)

Bridge Creek                  16            0           9
Bowen Ditch                   22            1           9
Buck Creek                    30            1          12
Sugar Creek                   74            3          30
Indian Creek                  77            1          21
Flint Creek                  100            2          23
Moots Creek                  133            3          39
Little Pine Creek            135           11          33
Burnett Creek                139            1          23
Big Shawnee Creek            167            1          15
Wea/Little Wea Creek         422            7          49
Wildcat Creek               2085           26          56
Tippecanoe River            5050           31 (c)      55
Wabash River              19,397           43 (c)      80
Table 2

Mussel species found during the study, categorized as live, fresh
shells, or weathered shells. The numbers refer to sites listed in Figure
1.

     Species                      Live

Actinonaias ligamentima     37
Alasmidonta marginata       37
Alasmidonta viridis         1, 20
Amblema plicata
Anodontoides ferussacianus  4, 22, 23, 50

Cyclonaias tuberculata
Elliptio dilatata
Fusconaia flava             19, 20
Lampsilis cardium           19, 34, 36, 39, 40
Lampsilis siliquoidea       2-4, 19-22, 34, 36, 37, 40-43
Lampsilis teres             37
Lasmigona complanata        37
Lasmigona compressa         4, 22
Lasmigona costata
Leptodea fragilis           34, 35
Ligumia recta               34
Pleurobema clava
Potamilus alatus            34
Pyganodon grandis           3-5, 34, 36, 37
Quadrula pustulosa
Quadrula quadrula
Strophitus undulatus        4, 37
Toxolasma lividus           3
Toxolasma parvus            4
Tritogonia verrucosa
Truncilla truncata
Uniomerus tetralasmus
Utterbackia imbecillis      4

     Species                    Fresh shells

Actinonaias ligamentima     34-37
Alasmidonta marginata       36, 38
Alasmidonta viridis         3, 20, 21, 27
Amblema plicata
Anodontoides ferussacianus  3, 4, 20, 21, 23, 26, 32,
                             33, 40, 41, 43, 48
Cyclonaias tuberculata
Elliptio dilatata           37
Fusconaia flava             2, 3, 20, 36, 38
Lampsilis cardium           22, 34-36, 38, 40
Lampsilis siliquoidea       2-4, 20-22, 36, 39-41
Lampsilis teres             36
Lasmigona complanata        38
Lasmigona compressa         3, 41, 49
Lasmigona costata           38, 40
Leptodea fragilis           34, 35
Ligumia recta               36, 38
Pleurobema clava
Potamilus alatus            34
Pyganodon grandis           3, 4, 34, 36, 38
Quadrula pustulosa          36
Quadrula quadrula           35
Strophitus undulatus        36, 38, 40
Toxolasma lividus           3
Toxolasma parvus            3, 20, 36, 51
Tritogonia verrucosa        35
Truncilla truncata          34
Uniomerus tetralasmus       3, 4
Utterbackia imbecillis      4

     Species                     Weathered shells

Actinonaias ligamentima     35, 37, 44
Alasmidonta marginata       34, 36
Alasmidonta viridis         1, 10, 17-19, 21, 22 24, 36, 40, 46
Amblema plicata             35-37
Anodontoides ferussacianus  10, 13, 15, 18-22, 24, 26,
                             29-34, 37, 39, 40, 42, 46-50
Cyclonaias tuberculata      37
Elliptio dilatata           35
Fusconaia flava             2, 19, 34-37, 40, 41
Lampsilis cardium           17, 18, 20-22, 24, 34-41, 49
Lampsilis siliquoidea       2, 18-23, 34-41
Lampsilis teres             36
Lasmigona complanata        34-37
Lasmigona compressa         46
Lasmigona costata           36, 37, 40
Leptodea fragilis           35
Ligumia recta               34-37, 39-41
Pleurobema clava            36, 37
Potamilus alatus
Pyganodon grandis           2, 36, 37
Quadrula pustulosa          35, 36
Quadrula quadrula           35
Strophitus undulatus        34-37
Toxolasma lividus
Toxolasma parvus            4, 16, 18, 20
Tritogonia verrucosa        35-38
Truncilla truncata
Uniomerus tetralasmus       4
Utterbackia imbecillis      36
Table 3

Abundance of live mussels found in Tippecanoe County in this survey. The
percentage of the toal collection for hte county is also shown.

                            Number
                            of live
Species                     mussels  Percentage

Lampsilis siliquoidea        127       58.0%
Anodontoides ferussacianus    21        9.6%
Pyganodon grandis             21        9.6%
Toxolasma parvus              11        5.0%
Utterbackia imbecillis         7        3.2%
Lampsilis cardium              5        2.3%
Fusconaia flava                4        1.8%
Alasmidonta viridis            4        1.8%
Leptodea fragilis              4        1.8%
Lasmigona complanata           3        1.4%
Actinonaias ligamentina        2        0.9%
Lasmigona compressa            2        0.9%
Toxolasma lividus              2        0.9%
Potamilus alatus               2        0.9%
Strophitus undulatus           1        0.46%
Alasmidonta marginata          1        0.46%
Lampsilis teres                1        0.46%
Ligumia recta                  1        0.46%