Date of Award

8-2012

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Legacy Department

Wildlife and Fisheries Biology

Advisor

English, William R

Committee Member

English , William R

Committee Member

Eversole , Arnold G

Committee Member

Post , Christopher J

Committee Member

Schuster , Guenter A

Abstract

A taxonomic study of the crayfish species Cambarus (Hiaticambarus) longirostris was conducted. Multivariate and univariate statistical analyses of morphometric data and examination of morphological characters revealed the existence of four undescribed species from populations previously considered to belong to C. longirostris; these were located on the southern extents of the range of C. longirostris. Three of these new species were morphologically similar to the group of species containing C. coosawattae, C. chasmodactylus, C. elkensis, C. longirostris, C. longulus, and C. manningi, while one was morphologically similar to the C. fasciatus, C. girardianus, and C. speciosus group. Cambarus Species A, C. Species D, and C. Species E were morphologically similar to C. longirostris and were found in tributaries of the Tennessee River in north Alabama and south Tennessee. Cambarus Species D and C. Species E were found in the Flint River drainage in Alabama and Tennessee but were not collected together. Morphologically, C. Species D differed from C. longirostris and the other putative species in possessing a carina on the acumen of the rostrum, by dactyl tuberculation, and by pigmentation pattern. Cambarus Species A and C. Species E differed from C. longirostris and from each other in aspects of chela morphometrics and in the presence or absence of qualitative characters. Individuals of C. Species A had a corneous spine on the base of the ventral surface of the rostrum, and in individuals of C. Species E the abdominal pleura were acute. Cambarus Species B was found in the upper Savannah River system in South Carolina and was morphologically similar to C. fasciatus. The known range of each of these species is restricted, and much of the suitable habitat for C. Species B was inundated by reservoir construction in the upper Savannah River drainage in the 1960s and 1970s. Three of the new species are considered Endangered using American Fisheries Society conservation categorization (C. Species B, C. Species D, and C. Species E), and C. Species A is considered Vulnerable. This study also addressed the general life history patterns of an imperiled crayfish, Cambarus (H.) elkensis. The population studied had a life span of five years, was capable of reproducing at about three years of age, and had one reproductive event per year. Females of this population of C. elkensis underwent reproductive form alternation. This is the first report of form alternation in the genus Cambarus and indicates that crayfish life histories are likely more complex than generally accepted.

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