Development of a Captive Rearing Protocol for Cambarus Crayfish: A Pilot Study With New River Crayfish
Though considered one of the most imperiled animal groups in the country, North American crayfish have received little active conservation outside of regional inventories and isolated life history studies. Captive rearing of endangered crayfish is a potential avenue of recovery, especially for species occurring in regions where stream degradation is actively occurring, if stream recovery is possible post disturbance. To see if it is conceivable to rear Cambarus species from egg to adult, a pilot study was initiated with New River Crayfish (Cambarus chasmodactylus) as surrogates for endangered species. Ten ovigerous female C. chasmodactylus were captured in Anthony Creek, West Virginia and relocated to 40 gallon rearing tanks, with two females placed in each tank. Two treatment groups, natural and artificial were tested to determine if natural conditions were needed for successful rearing of neonates. Natural tanks included small slab boulders as hides; artificial tanks maintained 30 cm terra cotta disks as hides. All female’s eggs hatched, and underwent development to stage four instars, without a difference in size, survival, or time to stage four between treatment groups. Instars were segregated into two additional treatments following stage four development. With mother neonates were allowed to stay with their mothers, and without mother neonates were separated from their mothers. Growth and survival between groups was similar, though the largest neonates were associated with the with mother group. Future efforts will focus on determining age to sexual maturity in captivity.
Dept of Natural Science and Mathematics’, West Liberty University, West Liberty, West Virginia; 2 Dept of Natural Science and Mathematics’, West Liberty University, West Liberty, West Virginia; 3 Dept of Natural Science and Mathematics’, West Liberty University, West Liberty, West Virginia
30 • Michael J. Lucero, Raquel A. Fagundo, Nicole M. Sadecky, Zachary J. Loughman
Determination of Causal Mechanisms in Cambarus Crayfish Assemblage Structure in Central Virginia
Crayfishes are receiving more research attention currently than ever before. A focus of this research is determining how similar crayfish species delegate resources amongst members of a localized crayfish assemblage. To answer this question, members of the crayfish Genus Cambarus were sampled across the Upper and Middle James and Roanoke basins in Virginia over the 2012/2013 summers season. Ohio EPA Quality Habitat Evaluation Sheets were filled out at each site, with each subscore used to represent habitat specifics (substrate, channel width, overall habitat quality etc.). Scores were matched with species presence/absence data for each taxa occurring in the selected watersheds, then modeled for each species using logistic regression, to determine which habitat variables correlated with each taxa presence at a site. Cambarus sp. C, Cambarus bartonii and Cambarus longulus were the crayfishes that made up the regions Cambarus assemblage. Logistic regression results from sampling one hundred twelve sites indicated that each Cambarus species presence was dependent on different QHEI metrics. Cambarus bartonii presence was correlated to stream gradient (ΔAICc= 0.00), Cambarus sp. C. presence was correlated to pool quality (ΔAICc= 0.00), and C. longulus presence was correlated to substrate type (ΔAIC= 0.00). In addition to specific habitat parameters, different cambarid taxa dominated different stream orders, and riffle, run and pool habitats across all watersheds studied. Results from this studied provided evidence for specific habitats parameters that are important drivers in crayfish assemblage construction and maintenance.
Dept of Natural Science and Mathematics, West Liberty University, West Liberty, WV
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31 • Cathryn H. Greenberg1, Beverly Collins2, W. Henry McNab1, Douglas Miller3
Introduction: Natural Disturbances Shaping the Structure and Composition of Central Hardwood Forests
Natural resource professionals often seek reference conditions, based on the historic range of variation in natural disturbances, for defining forest management and restoration objectives. In upland hardwood forests of the Central Hardwoods Region, wind, fire, ice, drought, insect pests, oak decline, floods, and landslides are recurring or episodic natural disturbances that can kill or damage scattered- to small or large groups of trees across small to large areas. The spatial extent, frequencies, and severities differ among these natural disturbance types and create mosaics and gradients of structural conditions and canopy openness within stands and over the landscape. A new (2012) forest planning rule requires that national forests be managed to sustain ecological integrity and within the historic range of variation of natural disturbances and vegetation structure. This highlights the need to use best available science to describe the historic types, frequencies, and severities of natural disturbances, and the scales and gradients of forest structural conditions they created. This symposium brings together experts to address how a wide variety of natural disturbance types historically created heterogeneous structure within central hardwood forests. Here, we introduce the region and historical range of natural disturbance to provide a foundation for the symposium and further discussion of whether, and how, historic disturbance regimes should solely guide forest management on national forests and other public lands.
1 USDA Forest Service, SRS, Asheville NC; 2 Dept of Biology, Western Carolina University, Cullowhee, NC; 3 ATMS Dept, University of North Carolina Asheville, Asheville, NC
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32 • Justin L. Hart
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