Date of Award
8-2024
Degree Type
Dissertation
Degree Name
Doctor of Philosophy (PhD)
School
Ocean Science and Engineering
Committee Chair
Dr. M. Zachary Darnell
Committee Chair School
Ocean Science and Engineering
Committee Member 2
Dr. Kelly M. Darnell
Committee Member 2 School
Ocean Science and Engineering
Committee Member 3
Dr. Chet Rakocinksi
Committee Member 3 School
Ocean Science and Engineering
Committee Member 4
Dr. Jeffery Levinton
Abstract
Fiddler crabs live on the edge of their thermal tolerance limits, balancing the need to thermoregulate with the need to mate. Previous research suggests that increased temperature reduces fiddler crab surface activity time, thus decreasing mating opportunities, throughout the range species with greatest impacts to low latitude populations. The less studied missed mating opportunities associated with behavioral compensation for thermal stress are crucial to understanding species vulnerability to climate change. In this dissertation, I describe a combination of experimental and observational approaches in the field and in the laboratory to investigate the physiological and behavioral responses of fiddler crabs to thermal stress, and behavioral mechanisms for mitigating this stress.
Using habitat quality data and physiological stress measurements of males from three populations, I found that Leptuca pugilator regulate temperature and hydration within optimum levels throughout their latitudinal range, though physiological condition, thermal tolerance limits, and acclimation ability was greatest in the northern most population. In the context of male burrow retreat vs. continued courtship, I found that behavioral decisions depend on the degree of thermal risk, likelihood of attracting a mate, and degree of competition. High temperatures limited time males spent on the surface, representing direct opportunity cost of thermoregulatory behaviour. When the chance of attracting a mate was high, males took greater thermal risk by staying on the surface longer at all observed in situ temperatures. However, males took the greatest thermal risk at lower temperatures when there were waving males nearby, despite the presence or absence of a female.
Copyright
Talene G. Yeghissian, 2024
Recommended Citation
Yeghissian, Talene G., "Impact of Thermal-hydric Stress of Physiological Performance and Mating Behavior of Fiddler Crabs" (2024). Dissertations. 2260.
https://aquila.usm.edu/dissertations/2260
Included in
Comparative and Evolutionary Physiology Commons, Marine Biology Commons, Population Biology Commons