Date of Award

2013

Degree Name

Biological Sciences

College

College of Science

Type of Degree

M.S.

Document Type

Thesis

First Advisor

Zachary Loughman

Second Advisor

David Mallory

Third Advisor

Mindy Armstead

Fourth Advisor

Thomas Jones

Fifth Advisor

Thomas K. Pauley

Abstract

Crayfish are the third most endangered faunal group in the world behind freshwater snails and unionid mussels. A better understanding of each species’ life history is vital in order to aid in crayfish conservation; however, little to no life history information is available for most crayfish. Recently, an undescribed species of crayfish, Cambarus theepiensis, was discovered in the Cumberland Mountains of West Virginia and Eastern Kentucky. In conjunction with the species’ scientific description, life history data was collected from May 2012 through April 2013 from two sites located within the Twelvepole watershed of southwestern West Virginia. Animals were collected monthly for one continuous year to determine the annual life history of this species. With the exception of ten females retained monthly for dissection and gonadal development analysis, all animals were returned to streams following demographic and morphometric analysis. Mature females showed signs of glair development in early May. Egg extrusion was noted in early June, with first through third stage instars occurring in July and concluding in August, before becoming free living juveniles by late August /September. Evidence for possible overwintering with young was also found as a mature female with free living juveniles was collected in early April. Mature female total carapace length (TCL) ranged from 29.7-52.4mm. Evidence was found supporting the hypothesis that form change also occurs in female cambarid crayfishes in C. theepiensis. Form I males were collected throughout the year, but reached their highest densities May through August. Form I male TCL ranged from 30.6-50.6mm. Size cohorts determined through histograms indicate six size cohorts existed between both streams following introduction of young of the year (YOY) in late summer. Cambarus theepiensis appears to have life history characteristics similar to previous Cambarus species whose life histories have been determined.

Subject(s)

Crayfish - Ecology - West Virginia.

Crayfish culture - Ecology - West Virginia.

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