Dissertation/Thesis Abstract

Ecology, systematics, and conservation of West Virginia's crayfishes
by Loughman, Zachary J., Ph.D., Indiana State University, 2011, 265; 3491232
Abstract (Summary)

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 carinirostris, Cambarus bartonii cavatus, Cambarus robustus and Cambarus thomai. Cambarus thomai is the most ubiquitous burrowing species occurring along the floodplain. The genus Orconectes consists of two native species, Orconectes obscurus and Orconectes sanbornii; and two invasive taxa, O. virilis and O. rusticus. Orconectes obscurus has experienced a range extension to the south and occupies streams formerly occupied by O. 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 fodiens, and Procambarus acutus are limited to the historic preglacial Marietta River Valley.

Several invertebrate and vertebrate taxa utilize crayfish burrows for various aspects of their life history, making the conservation of burrowing crayfishes important to the maintenance of both crayfishes and burrow obligate species. Very little research has examined habitat parameters for burrowing crayfish occupancy of a given location. Occupancy rates were modeled for two primary burrowing crayfishes, Fallicambarus fodiens and Cambarus thomai that occur in the historic Marietta River Valley associated with the Ohio and Kanawha River confluence in West Virginia. Although the influence of covariates on site occupancy differed between species, forested habitats were important for floodplain populations of F. fodiens and C. thomai. Conservation actions should preserve forest tracts along river floodplains to ensure stable F. fodiens populations.

The ecology of primary burrowing crayfishes is poorly understood, especially for high-elevation species. An ecological study of Cambarus ( Jugicambarus) dubius was conducted at Terra Alta, Preston County, West Virginia (elevation 781 m). The study provided life history information including size at sexual maturity, age cohort designation, and age estimation.

During the summer of 2008, West Virginia’s Cheat River basin’s crayfish fauna was surveyed. Survey sites (n = 66) were randomly generated via GIS. Crayfishes were collected with seines or by hand and habitat and physiochemical parameters were noted at each site. Cambarus b. bartonii, C. carinirostris, and O. obscurus were previously documented within the Cheat River system by Schwartz and Meredith (1962). Jezerinac et al. (1995) documented Cambarus carinirostris, Cambarus dubius,Cambarus monongalensis and O. obscurus occurring within the basin. Our efforts support Jezerinac’s findings. Schwartz and Meredith’s data indicated depauperate populations of Cambarus throughout the basin in 1956.

A major conservation issue for West Virginia crayfishes is the presence of undescribed diversity in the state. Many endemic taxa reside within West Virginia that currently are not recognized taxonomically. Cambarus 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 majority of West Virginia's crayfish fauna is currently stable. Significant impacts threatening the conservation status of the crayfish fauna include habitat degradation, with habitat destruction and fragmentation being the most pressing cause of imperilment in the state. Habitat altercation specifically impacts burrowing crayfishes by eliminating important habitats, like ephemeral pools, that are needed during burrowing crayfish early life history. Efforts to remediate past deleterious land use practices can have a positive effect on crayfish recruitment rates and are important steps towards maintenance of West Virginia crayfish populations. (Abstract shortened by UMI.)

Indexing (document details)
Advisor: Whitaker, John O.
Commitee: Mitchell, William A., Scott, Peter E., Simon, Thomas P., Welsh, Stuart A.
School: Indiana State University
Department: Biology
School Location: United States -- Indiana
Source: DAI-B 73/05, Dissertation Abstracts International
Source Type: DISSERTATION
Subjects: Ecology, Conservation, Zoology
Keywords: Cambarus, Crayfishes, Fallicambarus, Orconectes, West virginia
Publication Number: 3491232
ISBN: 9781267131492
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