Conservation, Biology, and Natural History of Crayfishes from the Southern US 2010 Southeastern Naturalist 9(Special Issue 3):1–10 Foreword Zachary J. Loughman, Thomas P. Simon, and Stuart A. Welsh During the last several decades, declines in crayfish diversity have generated an increased interest in the conservation and management of freshwater crayfishes. The crayfish fauna of North America is represented by two families: Astacidae, with one genus on the Pacific slope, and Cambaridae, with 12 genera east of the Rocky Mountains. Cambaridae is a diverse family (over 500 species and subspecies), reaching its highest diversity within the southeastern United States. This center of crayfish diversity has become a center of conservation concern. Extirpation and declines of crayfish populations have resulted in an imperiled southeastern crayfish fauna. Crayfish conservation efforts are often constrained because the biology and natural history of many species are poorly understood. To encourage and synthesize crayfish research, a symposium was held at the 2008 annual meeting of the Southern Division of the American Fisheries Society in Wheeling, WV. Symposium presentations (n = 23) are represented in this special issue as peer-reviewed research papers or as the original symposium abstracts (Appendix 1). The research papers within this volume represent the Symposium’s initial emphasis on conservation, biology, and natural history of southeastern crayfishes. This symposium attracted the attention of researchers from a wider geographic region than that of the southeastern US (Fig. 1); hence, this proceedings reflects a broader geographic emphasis. The conservation of crayfishes would benefit from additional studies of geographic distributions and taxonomy. Species inventory studies can provide valuable distribution information for conservation and management of crayfishes. Further, studies of species inventory, morphology, and genetics lead to the discovery and description of new taxa. This volume includes information on crayfish distributions in Alabama, Arkansas, Georgia, Indiana, Maryland, Missouri, North Carolina, and West Virginia. Crayfishes are critical components of aquatic and terrestrial communities and ecosystems. Crayfishes are important prey species (Stein 1977), omnivores and predators (Nystrom 2002), shredder-collector facilitators (Heard and Richardson 1995), bioturbators (Usio and Townsend 2004), bioprocessors of vegetation and carrion (Taylor et al. 2007), geomorphic agents and ecosystem engineers (Statzner et al. 2000), and keystone species (Holdich 2002). These roles reflect the importance of crayfishes at community and ecosystem levels in various ecological systems, but these roles are often underemphasized and poorly understood (Momot 1995). The losses of crayfish diversity by population extirpation and geographic range reduction have altered community and ecosystem function. Some contributions of crayfishes to communities and ecosystems are noted in this volume. 2 Southeastern Naturalist Vol. 9, Special Issue 3 Figure 1. Participants of the crayfish symposium of the Southern Division American Fisheries Society Meeting, Wheeling, WV, 28 February– 2 March 2008. Front row (kneeling); Sully Stocker, Jay Kilian, Casey Swecker, Tom Jones, Jacob Westhoff, Tom Simon, Jeff Simmons, Bob Distefano, Tyler Black. Back Row (standing); Whitney Stocker, Jim Fetzner, Matt Ashton, Casey Dillman, Brian Wagner, Roger Thoma, Guenter Schuster, Shane Welch, Jake Burskey, Nicole Garrison, Chris Skelton, Chris Taylor, Zac Loughman, and Stuart Welsh. 2010 Foreword 3 Crayfish biodiversity reaches its highest levels globally in the southeastern United States. Two regions in particular, the Appalachian Mountains and coastal plain swamps, harbor the majority of this diversity. In both of these regions, speciation events occurred frequently as crayfishes colonized these regions and became isolated. Following speciation, the majority of taxa did not radiate into additional watersheds, becoming specialized to the environmental theaters unique to single watersheds. This endemism lends itself to conservation issues. Given their limited natural ranges, endemic species are vulnerable to environmental perturbations. A major threat for all crayfishes is the introduction of non-native crayfishes (Lodge et al. 2000). Non-native crayfishes have often been labeled as “invasive” and, in some cases, led to the extirpation of native species. In this volume, effects of non-native species are noted in most papers on geographic distributions, and are the main focus of two papers. An improved understanding of the natural history of crayfish species is a critical need. Life-history parameters and behaviors are poorly understood. For most species, basic life-history parameters are unknown for size at sexual maturity, egg diameter, clutch size, embryonic and instar growth, post-instar growth, seasonality of breeding, and rates of fecundity and mortality. Conservation efficiency is hindered drastically for these animals if this information remains unknown. A major emphasis of this special issue is natural history, with 6 papers focusing on elucidating the natural history and behavioral ecology of a diverse array of species. Further research at population, community, and ecosystem levels will provide important and useful information for the management and conservation of crayfishes. An understanding of the biology and natural history of crayfishes is critical for crayfish conservation, but information needs are too complex to cover in a single symposium. As editors and astacologists, we hope that this special issue will act as a springboard for future symposia on crayfishes, since conservation concerns and the complexity of crayfish issues will benefit from research and collaboration. Literature Cited Heard, S.B., and J.S. Richardson. 1995. Shredder-collector facilitation in stream detrital food webs: Is there enough evidence? Oikos 72:359–366. Holdich, D.M. 2002. Chapter 1. Background and functional morphology. Pp. 3–29, In D.M. Holdich (Ed.). Biology of Freshwater Crayfish, Blackwell Science, Oxford, UK. 702 pp. Lodge, D.M., C.A. Taylor, D.M. Holdich, and J. Skurdal. 2000. Nonindigenous crayfishes threaten North American freshwater biodiversity: Lessons from Europe. Fisheries 25(8):7–20. Momot, W.T. 1995. Redefining the role of crayfish in aquatic ecosystems. Reviews in Fisheries Science 3:33–63. Nystrom, P. 2002. Ecology. Pp. 192–235, In D.M. Holdich (Ed.). Biology of Freshwater Crayfish, Blackwell Science, Oxford, UK. 702 pp. 4 Southeastern Naturalist Vol. 9, Special Issue 3 Statzner, B., E. Fievet, J.Y. Champagne, R. Morel, and E. Herouin. 2000. Crayfish as geomorphic agents and ecosystem engineers: Biological behavior affects sand and gravel erosion in experimental streams. Limnology and Oceanography 45:1030–1040. Stein, R.A. 1977. Selective predation, optimal foraging, and the predator-prey interaction between fish and crayfish. Ecology 58:1237–1253. Taylor C.A., G.A. Schuster, J.E. Cooper, R.J. Distefano, A.G. Eversole, P. Hamr, H.H. Hobbs III, H.W. Robison, C.E. Skelton, and R.F. Thoma. 2007. A reassessment of the conservation status of crayfishes of the United States and Canada after 10+ years of awareness. Fisheries 32:372–389. Usio, N., and C.R. Townsend. 2004. Roles of crayfish: Consequences of predation and bioturbation for stream invertebrates. Ecology 85:807–822. 2010 Foreword 5 Appendix 1. Abstracts that were not submitted as manuscripts, but were presented at the 2008 crayfish symposium, Southern Division American Fisheries Society meeting, Wheeling, WV. Crayfishes of Alabama—What We Do and Don't Know? Schuster*, G.A., Eastern Kentucky University, Richmond, KY; C.A. Taylor, Illinois Natural History Survey, Champaign, IL; and J.W. Johansen, Tulane University, New Orleans, LA; *Corresponding author - guenter.schuster@eku.edu. As a first step toward elucidating the current status of Alabama’s crayfish fauna, museums known to have significant crayfish collections were queried for their holdings from that state. A total of 4649 records of Alabama crayfishes were obtained from seven museums, of which 330 did not have enough information to be geo-referenced. The largest holdings were found in the National Museum of Natural History (2544 records). Specimen identifications were verified, and once verified, all records were geo-referenced. Geographic distribution strongly favored upland drainages in the northern and central portions of the state. The Tennessee River drainage was the single most- collected (1018 records, 23.6% of records) drainage. A total of 85 species of crayfishes are reported for the state of Alabama; only Orconectes virilis is deemed to be non-native. Even with the total number of crayfish records in museums, there is a need for crayfish inventory work in Alabama. Of all the records, a total of 3107 (76.3%) were collected prior to 1987, and 1379 (33.8%) were collected prior to 1970. In addition, there is a paucity of records from the coastal drainages of SE Alabama. There is also an under-representation of burrowing crayfishes, primarily those classified as either primary or secondary burrowers. Only 212 (4.9%) of all records are of burrowing species. Lastly, a limited amount of field work in Alabama has documented the presence of a species previously unreported for the state. The Crayfishes of the Ohio River Jones*, T.G., C. Swecker, and K. Donahue; Marshall University, Department of Integrated Science and Technology Huntington, WV; *Corresponding author - jonest@ marshall.edu. Very little is known about crayfishes in large rivers. Biological impacts and habitat alterations have resulted from pollution and maintenance of navigation channels. Since the Clean Water Act, improvements in water chemistry and possibly habitat have opened large rivers for re-colonization or expansion of refugia populations of aquatic species. In particular, segments of the Ohio River have seen significant improvements in water chemistry, habitats, and biological condition. Most crayfish biologists have ignored large rivers due to their perceived impacts, including lack of suitable habitat, high predator rates, and the difficulties in sampling. A series of projects from recent years has led to the sampling of the Ohio River from Pittsburg, PA to Cario, IL. We have sampled using a series of techniques including bank searches and SCUBA transects. From the mouth of the Muskingum River upstream, two native species occur in the mainstem. Orconectes obscurus accounts for 99% of the specimens in our collections. The invasive O. rusticus is the only crayfish we have found downstream from the Muskingum to Smithland Pool. In the Smithland pool, O. palicidus and O. rusticus occur. Further downstream, in 6 Southeastern Naturalist Vol. 9, Special Issue 3 pools 52 and 53, O. palicidus, O. pardalotus, and Cambarus rusticiformis were all collected. The dominance of O. rusticus in almost 700 miles of the Ohio River mainstem may mean the recently identified O. pardalotus could face extirpation. Invasion from downstream O. rusticus may jeopardize other Orconectid natives including the federally listed O. jeffersoni. The Conservation Status of Three Rare Crayfish Species in Southwest Virginia Thoma, R.F., Ohio University, Voinovich Center for Leadership and Public Affairs, Athens, OH; bartonii@roadrunner.com. Southwestern Virginia houses parts of the headwaters of three major North American river systems, the Tennessee, Ohio, and New. In these basins are found many rare and endemic species of aquatic organisms. Fishes, bivalves, snails, and crayfishes all have rare and endemic faunal components in the area. This paper presents the current results of a multi-year study of three crayfish species, Cambarus veteranus, Cambarus jezerinaci, and an undescribed species of Cambarus. Ranges for the species are well known within the state. Life histories, food preferences, habitat quality, and abundances are being determined. Of the three taxa, Cambarus veteranus is currently the most imperiled. At least one additional taxon with a highly restricted range has been discovered. This new species illustrates a significant problem for crayfish conservation in that many undescribed taxa in the Appalachian region are yet to be named and given conservation status. Currently, though insufficient and declining, moneys are available for studying known species, but funds are not available to resolve the many imperiled undescribed species. In addition, the purposeful underfunding of the USFWS's endangered species efforts forms a near insurmountable impediment to crayfish conservation efforts. Status and Distribution of the Rusty Gravedigger, Cambarus miltus: A Case of Recovery or Neglect? Taylor*, C.A., Illinois Natural History Survey Champaign, IL; and G.A. Schuster, Department of Biological Sciences Eastern Kentucky University Richmond, KY; *Corresponding author - ctaylor@mail.inhs.uiuc.edu. The primary burrowing Rusty Gravedigger, Cambarus miltus , is a narrowly endemic species formerly known only from Baldwin County, AL. In an effort to determine if listing under the Endangered Species Act is warranted, field surveys were conducted across portions of southern Alabama and western Florida. Our efforts have revealed the presence of new populations of the species and added to our knowledge of it’s habitat preferences. Historical field efforts and resulting literature are also discussed. Status of Crayfish in Indiana Simon, T.P., Bloomington, IN; Thomas_Simon@juno.com. The number of crayfish inhabiting Indiana includes 23 species. Primary burrowers are represented by four species, secondary burrowers by eight species, and tertiary burrowers by eleven species. Six checklists have been historically compiled for crayfish within Indiana; however, little is known about species distributions. 2010 Foreword 7 From the period between 1891 and 1955, only ten crayfish species were documented and significant confusion existed in our understanding of species distribution, identity, and biology. Most early studies (less than 1950) were focused on the “blind” cave crayfish of the Orconectes inermis complex. Descriptions of O. inermis inermis, O. pellucidus, and O. inermis testii have caused confusion over the status of O. inermis testii. Orconectes indianensis was studied and found to be stable, while conservation efforts are needed for two species. Significant efforts on species distribution have been accomplished. Prior to 1980, less than 150 sites were studied, with most done in caves and a few watersheds in northern Indiana. During 1980–1995, nearly 3000 collections were made statewide. Since 1995, intensive watershed surveys resulted in over 2000 sites. Another study included 675 sites that focused on the distribution and ecology of burrowing crayfish species, while additional intensive investigations collected 1080 sites in southern Indiana. Two new species have been described including Cambarus (Tubericambarus) polychromatus and Orconectes (Procericambarus) theaphionensis. Life-history studies have been initiated for all crayfish species, which will provide new information on preferred habitat, reproductive biology, age, growth, and diet. Additional species are pending formal description once distributions are known. A minimum of an additional eleven species will be added to the list of crayfish occurring in Indiana. Another two species are hypothetical in occurrence, while hypothetical species considered in the most recent checklist have all been confirmed statewide. It is possible that the actual number of crayfish occurring in Indiana may reach or exceed 36 species. Invasive Crayfishes of the New/Kanawha River System in West Virginia and a Comparison of Large River Collection Techniques Casey*, C.D., and T.J. Jones, Marshall University, Department of Integrated Science and Technology Huntington, WV; *Corresponding author - Swecker4@marshall.edu. There are six species of orconectid crayfishes historically recorded from West Virginia. Orconectes rusticus and Orconectes virilis are both non-native invasives. In 1978, researchers found a small population of O. rusticus in Fourpole creek in Huntington, WV and a second population on the Kanawha River. Orconectes virilis is historically known from the far eastern panhandle, and limited sites in the New/Kanawha River valley. Recent collections are locating a broader distribution of both species. This study focuses on New/Kanawha River from Bluestone Lake to the Ohio River. Currently there is no consensus on the best means for collecting crayfishes from large rivers. During this project SCUBA provided the easiest means of collecting crayfish from the Kanawha River and deep sections of the New River. Seining proved the best means of collecting in backwater areas and shallow portions of the New River. Underwater transects, pivot searches, meter surber samples, and other techniques were utilized to find the most efficient method for collecting crayfish in a large river environment. The resulting efforts suggest that O. rusticus is the dominant crayfish in the Kanawha River mainstem with O. virilis being the dominate orconectid species in the New River mainstem. Significant expansion of these two invasives in the New/Kanawha system, Ohio River, and other streams in West Virginia warrant greater attention by regulatory agencies, educators, and researchers. 8 Southeastern Naturalist Vol. 9, Special Issue 3 Preliminary Results of a Multi-year Survey to Monitor Orconectes rusticus, a Recent Invader of Maryland Ashton*, M.J., J. Gerber, J.V. Kilian, and A.J. Becker; Maryland Department of Natural Resources, Monitoring and Non-titdal Assessment, Annapolis, MD; *Corresponding author - mashton@dnr.state.md.us. In June 2007, Orconectes rusticus (Rusty Crayfish) was discovered in a tributary to the Monocacy River, Maryland. Following this discovery, the Maryland Department of Natural Resources joined with local government and academic institutions to begin a multi-year survey of O. rusticus throughout the Monocacy River watershed. Our goals were to: 1) determine the distribution of O. rusticus and other crayfish species and 2) establish baseline data to examine the effects of O. rusticus on native crayfishes in the Monocacy River. We surveyed at all bridge crossings (n = 21) on the Monocacy mainstem and tributaries. We collected O. rusticus (n = 464) from the six furthest upstream sites. They were the most abundant species (mean relative abundance ± SE = 0.86 ± 0.07) at five of those sites. Orconectes virilis composed nearly the entire crayfish community (0.98 ± 0.02) at nine sites within the middle portion of the river. The native O. obscurus was the predominant species (0.68 ± 0.06) at the lower seven sites. At 27 of 29 tributary sites sampled, O. virilis was the only species present. Non-native species were encountered throughout most of the watershed. A distinct pattern of species replacement by non-natives was evident in the Monocacy River. Only a few sites existed where species coexisted in similar relative abundance. Orconectes rusticus has become established throughout the upper 18 km of the Monocacy River in Maryland. If dispersal becomes evident, we hope to document changes in species distribution and community composition. Differential Production of Procambarus troglodytes Across a Large River Floodplain in South Carolina Welch*, S.M., and A.G. Eversole; Clemson University, Clemson, SC; *Corrsponding author - shanemwelch@gmail.com. The distribution of the freshwater crayfish Procambarus troglodytes is limited to parts of South Carolina and Georgia, where it inhabits floodplains. The species reproduces in association with flood pulses that seasonally inundate the habitat. We repeatedly sampled P. troglodytes at three sites within each of five landscape patch types. Crayfish were sexed, measured, and released. Frequency histograms of crayfish class intervals were visually inspected and used to identify cohorts. Seasonal shifts in cohorts, field observations of water depths at sampled sites, and historical flood patterns were used to infer the life cycle of P. troglodytes at the Congaree National Park in South Carolina. Changes in biomass within sampled locations were used to estimate production, which was then compared across the 5 landscape patch types. Procambarus troglodytes had an annual recruitment that coincided with the flood pulse. Production varied across the landscape, with shallower, more ephemeral habitats exhibiting highest production. The study highlights the importance of maintaining the spatial and temporal heterogeneity associated with river flood pulses. 2010 Foreword 9 Microhabitat Characterization of the Nashville Crayfish (Orconectes shoupi) in Mill Creek Watershed, Tennessee Walton*, C.F., and S.B. Cook; Tennessee Technological University, Department of Biology, Cookeville, TN; *Corresponding author - cfwalton21@gmail.com. The Nashville crayfish (Orconectes shoupi) is one of four federally listed endangered crayfish in the United States and the only one occurring in Tennessee. Orconectes shoupi is endemic to the Mill Creek watershed, which is located in the southwest portion of Nashville, TN in Williamson and Davidson counties. This watershed drains approximately 280 km2 within the Nashville Basin. The objectives for this study were to: (1) identify seasonal micro-habitat variables influencing habitat utilization, and (2) develop a predictive habitat model. Fifteen 200-m long sites were sampled throughout the Mill Creek watershed during the spring, summer, fall, and winter of 2007. Within each 200-m site, 11 transects perpendicular to flow were established at 20-m intervals. Random points along each transect were sampled with a 0.25-m2 quadrate sampler and 10 microhabitat variables were measured at each point. Logistic regression was used to model Nashville crayfish presence/absence as a function of one or more of these habitat variables. Currently, the Nashville Crayfish population appears stable, but because the species is endemic to Mill Creek watershed, which is increasingly undergoing urbanization, this status could change. Hopefully, models generated from this study will be helpful in maintaining and protecting this species. A Recreational Fishery for Longpincered Crayfish (Orconectes longidigitus) in Table Rock Reservoir, Missouri: Effects of Season and Environmental Factors on Trapping DiStefano*, R.J., M.E. Litvan, and K.J. Walker; Missouri Department of Conservation, Columbia, MO; *Corresponding author - Bob.DiStefano@mdc.mo.gov Longpincered Crayfish (Orconectes longidigitus), native to the White River drainage of Missouri and Arkansas, are among the largest crayfishes in North America, and a recreational fishery for them is becoming increasingly popular at Table Rock Reservoir in southwest Missouri. Possession of a Missouri fishing license allows harvest of 150 crayfish/day with an unlimited number of baited traps. This unusual North American fishery represents a unique opportunity for recreationalists and resource managers. However, no information exists concerning this crayfish's life history, ability to sustain exploitation, or how it may be effectively sampled by biologists. Our objectives were to determine if baited trap catch rates and sex ratios of captured Longpincered Crayfish vary among seasons and depth, and if they are affected by selected environmental variables. From September 2006 through September 2007, we sampled monthly at two sites representing two habitat types. At each site, 20 traps were deployed along transects at each of three depths (0–2 m, 6–8 m, 11–13 m). Temperature loggers were deployed with each trap line, and vertical temperature and dissolved oxygen profiles were obtained at each site. SCUBA was used to obtain substrate composition estimates. Crayfish catch rates were highest in autumn and late spring, low in winter, and generally higher at the gently sloping cove habitat site than the steeply sloping ledge site. Dissolved oxygen, temperature, and reservoir stratification/mixing appeared to influence catch rates at various depths. Results will be used to design future studies to determine effects of crayfish exploitation and ultimately address the potential need for modified regulations. 10 Southeastern Naturalist Vol. 9, Special Issue 3 Implementation of a Spatial-Temporal Focus to Predict Habitat Locations and Distribution of Cambarus veteranus Jones*, T.G., and K.B. Channell; Marshall University, Department of Integrated Science and Technology Huntington, WV; *Corresponding author - jonest@marshall. edu Statewide surveys in 1988 and 1989 found forty-nine Cambarus veteranus from only eight locations in the Upper Guyandotte watershed, WV. A pristine stream is speculated as the ideal habitat, yet, the upper Guyandotte is known for its extensive habitat alteration due to extractive industry. Current highway construction now intrudes on C. veteranus territory. Already, thirty-eight percent of all streams in the Upper Guyandotte River drainage are classified as impaired including C. veteranus’ type locality, Indian Creek, Wyoming County, WV. This impairment plays a role in the creation of habitat patches. Finding suitable habitat is advanced with the use of a geographic information system (GIS). Historical and current biological data provide the baseline validation values for suitable habitat and prediction models. The final suitability map shows optimum habitat locations for C. veteranus in the Upper Guyandotte by means of ArcMap® 8.1 thematic maps and spatial and geostatistical analysis. Final analysis reduced the potential search area, yet ground verification produced no updates for C. veteranus. Comparative Ecology of Orconectes (C.) obscurus and Cambarus (C.) b. bartonii in the Cacapon River Basin, West Virginia Garrison, N.L., West Liberty University, West Liberty, WV; ngarrison@westliberty. edu. Hobbs described three discrete crayfish behavioral groups based upon a species’ propensity to burrow. Two of these groups, secondary and tertiary burrowers, were examined in this study which elucidated differences in abiotic variable use between two sympatric, behaviorally distinct crayfish. Orconectes (C.) obscurus, a tertiary burrower, and Cambarus (C.) bartonii, a secondary burrower were used as models for their respective behavioral groups. A randomized group of forty 150-m stream reaches were selected by GIS for each sub-basin of the Cacapon River basin within West Virginia. Of the potential sites, 55 were chosen and surveyed in order to calculate catch-per-unit-effort values for each species at each site. Abiotic variables were also recorded at each site and included dissolved oxygen, pH, water temperature, stream order, hydroperiod, and stream gradient. Correlations were determined between CPUE and each abiotic variable to determine variable importance for each species. Results indicated that Orconectes (C.) obscurus prefers high-ordered streams and rivers and Cambarus (C.) b. bartonii is better suited for smaller order streams and headwater systems. High gradient, low stream order, and complete drawdown limit the distribution of Orconectes (C.) obscurus within the basin. Cambarus (C.) b. bartonii is limited by the presence of O. (C.) obscurus and large stream orders. Physiochemical variables such as dissolved oxygen, pH, and temperature did not have an impact on either species’ distribution.