Crayfish throughout the holarctic are found in association with an order of worms known as branchiobdellidans. This relationship has been confirmed as a cleaning symbiosis in several species. The Conhaway crayfish, Cambarus appalachiensis, is a species of crayfish endemic to the New River Basin in Virginia and West Virginia. We studied a population of C. appalachiensis in Sinking Creek in Newport, VA from March 2017 until February 2018. We collected morphological data and quantified the branchiobdellidan communities on 986 individuals, and kept note of egg brooding and young of year throughout the study period. The life cycle of C. appalachiensis was found to be similar to other large-bodied species of Cambarus crayfish. Molting occurred throughout the year, peaking in the months of April and September. This molting served as a disturbance effect to the symbiotic branchiobdellidan community and reset community assembly. The worm communities on larger, recently molted crayfish more closely resembled the less diverse communities on smaller crayfish. Most worms on recently molted crayfish were ones that we know are early colonizers. This thesis work provides the first life history information on a newly described species of Cambarus crayfish and provides both seasonal data on its branchiobdellidan associates and one of the first empirical examples of host ontogeny acting as a disturbance on a symbiotic community. / Master of Science / Crayfish throughout North America and Eurasia are the symbiotic partners to a number of small worms. This relationship has been confirmed as a cleaning symbiosis for several crayfish, similar to the cleaning stations at a coral reef. The Conhaway crayfish is a species of crayfish found in the New River Basin in Virginia and West Virginia. We studied a population of Conhaway crayfish in Sinking Creek in Newport, VA from March 2017 until February 2018. We collected data on the physical attributes of the crayfish, quantified the worms present on 986 individuals, and kept note of female crayfish with eggs and baby crayfish throughout the study period. The life cycle of the Conhaway crayfish was found to be similar to other large-bodied species of closely related crayfish. Molting, where the crayfish loses its shell and grows a new one, occurred throughout the year, peaking in the months of April and September. This molting served as a disturbance effect to the symbiotic worms, similar to how a wildfire might displace animals in a grassland ecosystem. The type and number of worms found on larger, recently molted crayfish more closely resemble the type and number of worms found on smaller crayfish. This thesis work provides the first information on the physical and reproductive attributes of a newly described species of crayfish and provides both seasonal data on its symbiotic worms and one of the first empirical examples of host growth and aging acting as a disturbance to symbiotic organisms living on that host.
| Identifer | oai:union.ndltd.org:VTETD/oai:vtechworks.lib.vt.edu:10919/91180 |
| Date | 03 July 2019 |
| Creators | McElmurray, Philip Edward |
| Contributors | Biological Sciences, Brown, Bryan L., Frimpong, Emmanuel A., Hawley, Dana M. |
| Publisher | Virginia Tech |
| Source Sets | Virginia Tech Theses and Dissertation |
| Detected Language | English |
| Type | Thesis |
| Format | ETD, application/pdf |
| Rights | In Copyright, http://rightsstatements.org/vocab/InC/1.0/ |
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