Zachary J. Loughman

Distribution and Conservation Standing of West Virginia Crayfishes

Abstract The diversity of crayfishes in West Virginia represents a transition between the species-rich southern Appalachian faunas and the depauperate crayfish diversity in the northeastern United States. Currently, 22 described species occur in the state, of which 6 are given S1 status, and 3 are introduced species. One species, Orconectes limosus (Spinycheek Crayfish) is considered extirpated within the past decade. Imperiled species include Cambarus veteranus (Big Sandy Crayfish), Cambarus elkensis (Elk River Crayfish), Cambarus longulus (Atlantic Slope Crayfish), and Cambarus nerterius (Greenbrier Cave Crayfish). Three species—O. virilis (Virile Crayfish), Orconectes rusticus (Rusty Crayfish), and Procambarus zonangulus (Southern White River Crawfish)—have introduced populations within the state. Procambarus acutus (White River Crawfish) occurs in bottomland forest along the Ohio River floodplain, and is considered native. Several undescribed taxa have been identified and currently are being described. A statewide survey was initiated in 2007 to document the current distribution and conservation status of crayfishes in West Virginia.

Ecology of Cambarus dubius (Upland Burrowing Crayfish) in North-Central West Virginia

Abstract The ecology of primary burrowing crayfishes is poorly understood, especially for high-elevation species. An ecological study of Cambarus (Jugicambarus) dubius (Upland Burrowing Crayfish) was conducted at Terra Alta, Preston County, WV (elevation 781 m). The study sought life-history information including size at sexual maturity, age cohort designation, and age estimation. The density and distribution of burrow portals of C. dubius were examined within and near seeps in forested and disturbed habitats. Data were also collected on intraspecific usage of burrows by commensal species. Size at maturity did not differ significantly for males and females. The average age of C. dubius was 1.5 years, and the oldest individuals were estimated at 7 years. Form change of C. dubius occurred synchronously within the population, a phenomenon not previously documented with primary burrowing Cambarus. Burrow portals had highest densities within 5 m of the center of seeps in forested habitats, but reached highest densities between 10 and 25 m from the center of seeps in disturbed habitats. Many commensal species of invertebrates and vertebrates used C. dubius burrows, data that demonstrates a community-level contribution of C. dubius. Information from this study represents most of the available ecological data from the northern range of this species, and is directly relevant for management and conservation of high-elevation populations of C. dubius.

West Virginia Crayfishes (Decapoda: Cambaridae): Observations on Distribution, Natural History, and Conservation

Abstract West Virginias crayfishes have received moderate attention since publication of Jezerinac et al.s (1995) monograph of the state fauna. Survey efforts were initiated over the summers of 2006 and 2007 to gather voucher material for the Indiana Biological Surveys Crustacean Collection. These collections have provided new information regarding the distribution, natural history, life history, taxonomy, and conservation status of Cambarus (Cambarus) carinirostris, C. (C.) bartonii cavatus, C. (C.) sciotensis, C. (Hiaticambarus) chasmodactylus, C. (H.) elkensis, C. (H.) longulus, C. (Jugicambarus) dubius, C. (Puncticambarus) robustus, Orconectes (Procericambarus) cristavarius, and O. (P.) rusticus. Orconectes (Faxonius) limosus has apparently been extirpated from West Virginia and should be removed from the states list of extant crayfishes.

Occupancy Rates of Primary Burrowing Crayfish in Natural and Disturbed Large River Bottomlands

ABSTRACT Among crayfish, primary burrowing species are the least understood ecologically. Many primary burrowing crayfish inhabit floodplains where forested landscapes have been fragmented by agricultural, industrial, or residential uses. In this study, site occupancy rates (&psgr;) were modeled for two primary burrowing crayfish, Fallicambarus fodiens (Cottle, 1863) and Cambarus thomai Jezerinac, 1993, from Ohio and Kanawha river floodplains in West Virginia, U.S.A. Fallicambarus fodiens is one of West Virginias rarest crayfish, while C. thomai is prevalent in most wetlands along both river floodplains. Occupancy rate modeling incorporated four environmental covariates (forest age, soil type, tree frequency, and land use). Based on presence/absence data, forests with tree ages > 100 years (&Dgr;QAICc = 0) and sites with loam soils (&Dgr;QAICc = 1.80) were most likely to harbor F. fodiens populations. For C. thomai, several models were supported owing to model selection uncertainty, but those with the land use covariate had more total model weight (total wi = 0.54) than all other covariate models. Cambarus thomai rarely occupied industrial/agricultural sites, but were often present in forested and residential sites. Although the influence of covariates on site occupancy differed between species, both taxa readily utilized mature forested habitats when available. Conservation actions for F. fodiens and C. thomai should focus on preserving forested tracts along large river floodplains

Crayfishes of Western Maryland: Conservation and Natural History

Abstract Conservation concerns for imperiled crayfish faunas have recently increased among resource management agencies. In Maryland, major concerns include the introduction of nonnative crayfishes and their impacts on native species. This study documented the species distribution and conservation standing of native and nonnative crayfishes of western Maryland. Native species include Orconectes (Crockerinus) obscurus (Allegheny Crayfish), Cambarus (Jugicambarus) dubius (Upland Burrowing Crayfish), Cambarus (Cambarus) bartonii bartonii (Common Crayfish), and Cambarus (Cambarus) carinirostris (Rock Crawfish). Introduced species are Orconectes (Gremicambarus) virilis (Virile Crayfish), Procambarus (Ortmannicus) acutus (White River Crawfish), and Cambarus (Tubericambarus) thomai (Little Brown Mudbug). Nonnative species were found primarily in areas of high anthropogenic activity, with populations of O. virilis and P. acutus isolated to impoundments. The presence of C. thomai in Maryland was first documented through this study, and represents one of the first situations globally of a primary burrowing crayfish outside of its native range. Major conservation threats to the native crayfish fauna of western Maryland include nonnative crayfishes, land development, and land-use practices.

Zoogeography, taxonomy, and conservation of West Virginia's Ohio River floodplain crayfishes (Decapoda, Cambaridae).

Abstract The crayfish fauna of West Virginia consists of 23 species and several undescribed taxa. Most survey efforts documenting this fauna have been conducted in lotic waterways throughout the Appalachian plateau, Allegheny Mountains, and Ridge and Valley physiographic provinces. Bottomland forests, swamps, and marshes associated with large river floodplain such as the Ohio River floodplain historically have been under-surveyed in the state. These habitats harbor the richest primary burrowing crayfish fauna in West Virginia, and are worthy of survey efforts. In an effort to fill this void, the crayfish fauna of West Virginia’s Ohio River floodplain was surveyed from 2004 through 2009. From this survey, nine species from four genera were documented inhabiting the floodplain. Zoogeography, biology, and conservation status is provided for all nine crayfishes. The dominant genus along the floodplain is Cambarus, which includes Cambarus (Cambarus) carinirostris, Cambarus (Cambarus) bartonii cavatus, Cambarus (Procambarus) robustus and Cambarus (Tubericambarus) thomai. Cambarus (Tubericambarus) thomai is the most prevalent burrowing species occurring along the floodplain. The genus Orconectes consists of two native species, Orconectes (Cambarus) obscurus and Orconectes (Cambarus) sanbornii; and two invasive taxa, Orconectes (Gremicambarus) virilis and Orconectes (Procambarus) rusticus. Orconectes (Cambarus) obscurus has experienced a range extension to the south and occupies streams formerly occupied by Orconectes (Cambarus) sanbornii. Both invasive taxa were allied with anthropogenic habitats and disturbance gradients. The genera Fallicambarus and Procambarus are represented by a single species. Both Fallicambarus (Cambarus) fodiens and Procambarus (Orconectes) acutus are limited to the historic preglacial Marietta River Valley.

Physical habitat and water quality correlates of crayfish distributions in a mined watershed

In mined watersheds, water quality alters aquatic faunas, but few studies have focused on associations between stream habitat and crayfish distributions. We examined associations of water quality and physical habitat quality on presence/absence of six crayfish species in the upper Kanawha River drainage of southern West Virginia, USA, a region with a long history of surface and mountaintop removal mining of coal. Data supported an association of physical habitat quality with the presence of four species (Cambarus carinirostris, Cambarus robustus, Cambarus cf. sciotensis, and Orconectes sanbornii). Cambarus bartonii cavatus and the non-native Orconectes virilis were associated with lower quality physical habitat than that of the other four species. Relative to other species, C. b. cavatus was associated with the lowest conductivity values, whereas O. virilis was associated with the highest conductivity values. Secondary and tertiary burrowers were generally associated with relatively high-quality physical habitat. However, C. b. cavatus, a crayfish known to burrow extensively in headwater streams, was associated with the lowest quality physical habitat. Physical habitat quality was generally supported over stream conductivity as a variable influencing crayfish distributions. Our data demonstrate the importance of stream habitat quality when assessing crayfish assemblages within mined watersheds.

First Record of Procambarus (Ortmannicus) acutus (White River Crayfish) in West Virginia, with Notes on its Natural History

Abstract Procambarus (Ortmannicus) acutus (White River crayfish) was added to West Virginias decapod crustacean fauna on 26 February, 2004, and this finding was the first record of the genus Procambarus in West Virginia. Six P. (O.) acutus (4 form-I males, 2 females) were collected in traps from a large vernal pool system 1.2 km east of Point Pleasant, Mason County. Several additional specimens were collected from this site during the spring of 2004, with an additional 3 populations discovered in the spring of 2005. White River Crayfish were collected in ephemeral pools, marshes, and roadside ditches. White River Crayfish were found in ephemeral systems only, and appear to have shifted aspects of their typical ecology to suit these systems in West Virginia. White River Crayfish distribution in West Virginia appears to be limited to the pre-glacial Marietta River Valley, and results suggest that it is a native species in West Virginia.

Baited Lines: An Active Nondestructive Collection Method for Burrowing Crayfish

Abstract A new method (baited lines) is described for the collection of burrowing crayfishes, where fishing hooks baited with earthworms and tied to monofilament leaders are used to lure crayfishes from their burrow entrances. We estimated capture rates using baited lines at four locations across West Virginia for a total of four crayfish taxa; the taxa studied were orange, blue, and blue/orange morphs of Cambarus dubius (Upland Burrowing Catfish), and C. thomai (Little Brown Mudbug). Baited-line capture rates were lowest for C. thomai (81%; n = 21 attempts) and highest for the orange morph of C. dubius (99%; n = 13 attempts). The pooled capture rate across all taxa was 91.5% (n = 50 attempts). Baited lines represent an environmentally nondestructive method to capture burrowing crayfishes without harm to individuals, and without disturbing burrows or the surrounding area. This novel method allows for repeat captures and long-term studies, providing a useful sampling method for ecological studies of burrowing crayfishes.

Cambarus (Puncticambarus) smilax, a new species of crayfish (Crustacea: Decapoda: Cambaridae) from the Greenbrier River basin of West Virginia

Abstract Cambarus (Puncticambarus) smilax is a stream-dwelling crayfish that appears to be endemic to the Greenbrier River basin in the Valley and Ridge province of West Virginia. Within the Greenbrier system it occurs primarily in tributaries to the Greenbrier mainstem, with stable populations in the East and West Fork, and Thorny, Knapp, and Deer creeks. The new species is morphologically most similar to C. (P.) robustus, from which it can be distinguished by a combination of the following characters: adult palm length comprising 73–76% of palm width as opposed to 63–70% in C. (P.) robustus; ventral surface of chela of cheliped with 0–2 subpalmar tubercles compared to 3–6 subpalmar tubercles in C. (P.) robustus; lack of tubercles on the dorsal surface of chela; longer, more tapering, less rectangular rostrum (47–52% rostrum width/length ratio) compared to C. (P.) robustus shorter, less tapering rectangular rostrum (54–63% rostrum width/length ratio); and the central projection of the form-I male gonopod curved ≤90 degrees to the shaft.