Master of Science, The Ohio State University, 1986, Graduate School

Committee: Not Provided (Other) Subjects:

Doctor of Philosophy, The Ohio State University, 1985, Graduate School

Committee: Not Provided (Other) Subjects: Biology

Doctor of Philosophy, The Ohio State University, 1973, Graduate School

Committee: Not Provided (Other) Subjects: Biology

Master of Science, The Ohio State University, 1978, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, The Ohio State University, 1964, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, The Ohio State University, 2007, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, The Ohio State University, 1923, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, The Ohio State University, 1960, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, The Ohio State University, 1962, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, The Ohio State University, 1936, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Arts, The Ohio State University, 1931, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, The Ohio State University, 1979, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, The Ohio State University, 1924, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Science, The Ohio State University, 1977, Graduate School

Committee: Not Provided (Other) Subjects:

Master of Arts (MA), Bowling Green State University, 1964, Biological Sciences

Committee: William B. Jackson (Advisor) Subjects: Biology

Master of Arts (MA), Bowling Green State University, 1963, Biological Sciences

Committee: Eugene Dickerman (Advisor) Subjects: Biology

Master of Arts (MA), Bowling Green State University, 1951, Biological Sciences

Committee: Everett C. Myers (Advisor) Subjects: Biology

Master of Arts (MA), Bowling Green State University, 1950, Biological Sciences

Committee: E. E. Dickerman (Advisor) Subjects: Biology

Doctor of Philosophy (PhD), Ohio University, 2022, Biological Sciences (Arts and Sciences)

Human induced environmental change has led to a decline in biodiversity worldwide. Freshwater ecosystems are heavily impacted by local land use changes and agricultural practices, resulting in a wide range of pollutants entering surface waters. These pollutants can produce a variety of physiological effects, but we know comparatively little about how organisms respond behaviorally. Behavioral responses to environmental stressors have been understudied, but behavioral responses can indicate the immediate ecological consequences of pollutants on populations. Behavioral responses are often first in a cascade of responses when organisms deal with environmental change. Behavior might be valuable as a tool for determining the mechanisms of how populations change over time, and could be used to understand how sensitive species are to environmental change. We often observe changes in behavior during the presence of environmental change, but less is known about whether these changes are plastic —giving an individual the ability to temporarily respond to a stressor and return to baseline behaviors after stressors pass— or irreversible. In addition, even less is known about the potential for these changes to be adaptive evolutionary response. My dissertation focused on two key aspects of behavioral variation: (1) the evolutionary and physiological mechanisms underlying mating behaviors and (2) how elevated nitrates affect behavioral variation, and if behavioral responses to nitrate are plastic responses, or evolutionary responses. 4 One behavior that plays a critical role in population growth and stability is female mate preferences. When a female's mating preferences is reduced, females mate more randomly, and the adaptive benefits of optimal mate choice are reduced. In my first chapter, I examined possibility that stressors could affect mating behaviors by determining if cortisol was associated with variation in female mating preferences. I performed (open full item for complete abstract)

Committee: Molly Morris (Advisor); Viorel Popescu (Committee Member); Kelly Johnson (Committee Member); John Schenk (Committee Member) Subjects: Biology; Ecology; Evolution and Development

Master of Science (MS), Ohio University, 2019, Biological Sciences (Arts and Sciences)

Unprecedented increases in sea surface temperatures may pose a significant threat to the finfish fauna associated with the continental shelf of the Southern Ocean, which is dominated, in terms of biomass, by fishes of the suborder Notothenioidei. These animals are noted for their extreme stenothermy, and the absence of circulating hemoglobin (Hb) in one notothenioid family, the Channichthyidae or icefishes. Previous studies have shown that icefishes have a reduced thermal tolerance compared to red-blooded notothenioids from the area surrounding the Western Antarctic Peninsula. Though the mechanism(s) underlying upper thermal limits in notothenioids (or in ectothermic animals more generally) is (are) not fully understood, several studies indicate that inability to maintain cardiac performance at elevated temperatures may play an important role. I hypothesized that biophysical and biochemical properties in the ventricular membranes of notothenioids could help to explain interspecific differences in heart rate variability and cardiac collapse. In this study, I determined membrane integrity (quantified as membrane leakage) and membrane fluidity (quantified as fluorescence depolarization) over a range of temperatures from ambient (0°C) to 20°C in membranes prepared from heart ventricles of six species of notothenioids including representatives from the white blooded family Channichthyidae (Hb-), which also differentially express cardiac myoglobin (Mb), and the red-blooded family Nototheniidae (Hb+). The species investigated included Chaenocephalus aceratus and Champsocephalus gunnari (Hb-/Mb-), Chionodraco rastrospinosus and Pseudochaenichthys georgianus (Hb-/Mb+), and Gobionotothen gibberifrons and Notothenia coriiceps (Hb+/Mb+). In addition, I measured membrane phospholipid composition and cholesterol contents in order to determine the lipids underlying the biophysical properties. I found that membranes from the icefishes exhibit the greatest fluidity, yet m (open full item for complete abstract)

Committee: Elizabeth Crockett Dr. (Advisor) Subjects: Biochemistry; Biology; Physiology