Available at: https://digitalcommons.calpoly.edu/theses/2897
Date of Award
8-2024
Degree Name
MS in Biological Sciences
Department/Program
Biological Sciences
College
College of Science and Mathematics
Advisor
Emily N. Taylor
Advisor Department
Biological Sciences
Advisor College
College of Science and Mathematics
Abstract
Ambush-hunting snakes have long been of great interest in the biology of fasting and starvation, as they are adapted to withstand well over a year without taking a meal. Well-justified ethical constraints have limited our understanding of their biology at the limits of these abilities. Unfortunate circumstances, in which the California Department of Fish and Wildlife confiscated over 50 Western Rattlesnakes (Crotalus oreganus) from an animal hoarder that had long neglected them, culminated in the euthanized animals ending up in the hands of our lab. Some of these snakes were extremely starved, being only one-half to one-third of the weight of wild snakes of the same length. We used dissection to determine the effects of starvation on the mass of their hearts, livers, kidneys, gallbladders, testes, and body fat. We also desiccated their hearts, livers, and kidneys to investigate effects on tissue water content in those organs. We used nano-indentation and photo analysis of bone cross sections to assess whether starvation had impacts on the material properties and structural integrity of their bones. We demonstrate that all measured organs dramatically shrink in response to starvation, with the exception of the gallbladder that shows the opposite response. The tissue water content of the liver and kidneys increases with the extent of starvation, and that of the heart appears to be unaffected. We found no evidence for changes in the material properties or structural integrity of rattlesnake bones in response to starvation. These results provide insight into how the body of one of the most fasting-adapted species of vertebrate responds to extreme starvation. Future work may need to act opportunistically to better understand these processes at different levels of biological organization.