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Though it is a widespread adaptation in humans and many other animals, parental care comes in a variety of forms and its subtle physiological costs, benefits, and tradeoffs related to offspring are often unknown. Thus, I studied the hydric, respiratory, thermal, and fitness dynamics of maternal egg-brooding behavior in Children's

Though it is a widespread adaptation in humans and many other animals, parental care comes in a variety of forms and its subtle physiological costs, benefits, and tradeoffs related to offspring are often unknown. Thus, I studied the hydric, respiratory, thermal, and fitness dynamics of maternal egg-brooding behavior in Children's pythons (Antaresia childreni). I demonstrated that tight coiling detrimentally creates a hypoxic developmental environment that is alleviated by periodic postural adjustments. Alternatively, maternal postural adjustments detrimentally elevate rates of egg water loss relative to tight coiling. Despite ventilating postural adjustments, the developmental environment becomes increasingly hypoxic near the end of incubation, which reduces embryonic metabolism. I further demonstrated that brooding-induced hypoxia detrimentally affects offspring size, performance, locomotion, and behavior. Thus, parental care in A. childreni comes at a cost to offspring due to intra-offspring tradeoffs (i.e., those that reflect competing offspring needs, such as water balance and respiration). Next, I showed that, despite being unable to intrinsically produce body heat, A. childreni adjust egg-brooding behavior in response to shifts in nest temperature, which enhances egg temperature (e.g., reduced tight coiling during nest warming facilitated beneficial heat transfer to eggs). Last, I demonstrated that A. childreni adaptively adjust their egg-brooding behaviors due to an interaction between nest temperature and humidity. Specifically, females' behavioral response to nest warming was eliminated during low nest humidity. In combination with other studies, these results show that female pythons sense environmental temperature and humidity and utilize this information at multiple time points (i.e., during gravidity [egg bearing], at oviposition [egg laying], and during egg brooding) to enhance the developmental environment of their offspring. This research demonstrates that maternal behaviors that are simple and subtle, yet easily quantifiable, can balance several critical developmental variables (i.e., thermoregulation, water balance, and respiration).
ContributorsStahlschmidt, Zachary R (Author) / DeNardo, Dale F (Thesis advisor) / Harrison, Jon (Committee member) / McGraw, Kevin (Committee member) / Rutowski, Ronald (Committee member) / Walsberg, Glenn (Committee member) / Arizona State University (Publisher)
Created2011
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We examined the evolutionary morphological responses of Drosophila melanogaster that had evolved at constant cold (16°), constant hot (25°C), and fluctuating (16° and 25°C). Flies that were exposed to the constant low mean temperature developed larger thorax, wing, and cell sizes than those exposed to constant high mean temperatures. Males

We examined the evolutionary morphological responses of Drosophila melanogaster that had evolved at constant cold (16°), constant hot (25°C), and fluctuating (16° and 25°C). Flies that were exposed to the constant low mean temperature developed larger thorax, wing, and cell sizes than those exposed to constant high mean temperatures. Males and females both responded similarly to thermal treatments in average wing and cell size. The resulting cell area for a given wing size in thermal fluctuating populations remains unclear and remains a subject for future research.
ContributorsAdrian, Gregory John (Author) / Angilletta, Michael (Thesis director) / Harrison, Jon (Committee member) / Rusch, Travis (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2015-05
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Studies of animal contests often focus solely on a single static measurement of fighting ability, such as the size or the strength of the individual. However, recent studies have highlighted the importance of individual variation in the dynamic behaviors used during a fight, such as, assessment strategies, decision making, and

Studies of animal contests often focus solely on a single static measurement of fighting ability, such as the size or the strength of the individual. However, recent studies have highlighted the importance of individual variation in the dynamic behaviors used during a fight, such as, assessment strategies, decision making, and fine motor control, as being strong predictors of the outcome of aggression. Here, I combined morphological and behavioral data to discover how these features interact during aggressing interactions in male virile crayfish, Faxonius virilis. I predicted that individual variation in behavioral skill for decision making (i.e., number of strikes thrown), would determine the outcome of contest success in addition to morphological measurements (e.g. body size, relative claw size). To evaluate this prediction, I filmed staged territorial interactions between male F. virilis and later analyzed trial behaviors (e.g. strike, pinches, and bout time) and aggressive outcomes. I found very little support for skill to predict win/loss outcome in trials. Instead, I found that larger crayfish engaged in aggression for longer compared to smaller crayfish, but that larger crayfish did not engage in a greater number of claw strikes or pinches when controlling for encounter duration. Future studies should continue to investigate the role of skill, by using finer-scale techniques such as 3D tracking software, which could track advanced measurements (e.g. speed, angle, and movement efficiency). Such studies would provide a more comprehensive understanding of the relative influence of fighting skill technique on territorial contests.

ContributorsNguyen, Phillip Huy (Author) / Angilletta, Michael (Thesis director) / McGraw, Kevin (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
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Three populations of experimentally evolved Drosophila melanogaster populations made up of high temperature (H, constant 25 ᵒC), low temperature (C, constant 16 ᵒC) and temporal homogeneity (T, environment changes between 16 ᵒC and 25 ᵒC) were prepared and assayed to determine difference in citrate synthase activity. Between the three groups,

Three populations of experimentally evolved Drosophila melanogaster populations made up of high temperature (H, constant 25 ᵒC), low temperature (C, constant 16 ᵒC) and temporal homogeneity (T, environment changes between 16 ᵒC and 25 ᵒC) were prepared and assayed to determine difference in citrate synthase activity. Between the three groups, the results were inconclusive: the resulting reaction rates in units of nmol min-1mgfly-1 were 81.8 + 20.6, 101 + 15.6, and 96.9 + 25.2 for the hot (H), cold (C), and temporally homogeneous (T) groups, respectively. We conclude that the high associated variability was due to a lack of control regarding the collection time of the experimentally evolved Drosophila.
ContributorsBelohlavek, David (Author) / Angilletta, Michael (Thesis director) / Francisco, Wilson (Committee member) / Barrett, The Honors College (Contributor) / Department of Chemistry and Biochemistry (Contributor)
Created2015-05
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I am evaluating the genomic basis of a model of heat tolerance in which organisms succumb to warming when their demand for oxygen exceeds their supply. This model predicts that tolerance of hypoxia should correlate genetically with tolerance of heat. To evaluate this prediction, I tested heat and hypoxia tolerance

I am evaluating the genomic basis of a model of heat tolerance in which organisms succumb to warming when their demand for oxygen exceeds their supply. This model predicts that tolerance of hypoxia should correlate genetically with tolerance of heat. To evaluate this prediction, I tested heat and hypoxia tolerance in several genetic lines of Drosophila melanogaster. I hypothesized that genotypes that can fly better at high temperatures are also able to fly well at hypoxia. Genotypes from the Drosophila Genetic Reference Panel (DGRP) were assessed for flight at hypoxia and normal temperature (12% O2 and 25°C) as well as normoxia and high temperature (21% O2 and 39°C). After testing 66 lines from the DGRP, the oxygen- and capacity-limited thermal tolerance theory is supported; hypoxia-resistant lines are more likely to be heat-resistant. This supports previous research, which suggested an interaction between the tolerance of the two environmental variables. I used this data to perform a genome-wide association study to find specific single-nucleotide polymorphisms associated with heat tolerance and hypoxia tolerance but found no specific genomic markers. Understanding factors that limit an organism’s stress tolerance as well as the regions of the genome that dictate this phenotype should enable us to predict how organisms may respond to the growing threat of climate change.
ContributorsFredette-Roman, Jacob Daniel (Author) / Angilletta, Michael (Thesis director) / VandenBrooks, John (Committee member) / Youngblood, Jacob (Committee member) / School of Life Sciences (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
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Ectotherms rely on external heat to attain target body temperatures which can vary based on the animal’s current physiological activity. Many ectotherms become thermophilic (“heat-loving”) during crucial physiological processes like digestion and reproduction, behaviorally thermoregulating to increase body temperature higher than what they otherwise prefer. However, there is a positive

Ectotherms rely on external heat to attain target body temperatures which can vary based on the animal’s current physiological activity. Many ectotherms become thermophilic (“heat-loving”) during crucial physiological processes like digestion and reproduction, behaviorally thermoregulating to increase body temperature higher than what they otherwise prefer. However, there is a positive relationship between body temperature and water loss that dictates increasing body temperature typically elicits an increase in water loss. Animals that inhabit areas where water is at least seasonally limited (e.g., deserts, wet-dry forests) may face a tradeoff between prioritizing behavioral thermophily to optimize physiological processes versus prioritizing water balance and potentially sacrificing some aspect of total performance capability.It is thus far unknown how reduced water availability and subsequent dehydration may influence thermophily in ectotherms. I hypothesized that behaviorally thermoregulating ectotherms exhibit thermophily during critical physiological events, and the extent to which thermophily is expressed is influenced by the animal’s hydric state. Using Children’s pythons (Antaresia childreni), I investigated the effects of dehydration on behavioral thermophily during digestion and reproduction. I found that dehydration caused a suppression in digestion-associated thermophily, where dehydrated snakes returned to pre-feeding body temperature sooner than they did when they were hydrated. In contrast, water deprivation at different reproductive stages had no effect on thermophily despite leading to a significant increase in the female’s plasma osmolality. ii Additionally, the timing of water deprivation during reproduction had differing effects on plasma osmolality and circulating triglyceride, total protein, and corticosterone concentrations. My research provides evidence of the sensitive and complex dynamic between body temperature, water balance, and physiological processes. At a time when many dry ecosystems are becoming hotter and drier, my investigation of dehydration and its influence on thermal dynamics and physiological metrics provides insight into cryptic effects on the vital processes of digestion and reproduction.
ContributorsAzzolini, Jill L. (Author) / Denardo, Dale F. (Thesis advisor) / John-Alder, Henry (Committee member) / Angilletta, Michael (Committee member) / Pratt, Stephen (Committee member) / Arizona State University (Publisher)
Created2023
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The migratory grasshopper (Melanoplus sanguinipes) is one of the most economically important grasshoppers in the western rangelands of the United States (US), capable of causing incredible amounts of damage to crops and rangelands. While M. sanguinipes has been the focus of many research studies, areas like field nutritional physiology and

The migratory grasshopper (Melanoplus sanguinipes) is one of the most economically important grasshoppers in the western rangelands of the United States (US), capable of causing incredible amounts of damage to crops and rangelands. While M. sanguinipes has been the focus of many research studies, areas like field nutritional physiology and ecology, and interactions between nutritional physiology and biopesticide resistance have very little research. This dissertation presents a multifaceted approach through three research-driven chapters that examine the nutritional physiology of M. sanguinipes and how it interacts with an entomopathogenic fungus for grasshopper management, as well as the challenges of using biopesticides for grasshopper management. Using the Geometric Framework for Nutrition (GFN), I established baseline macronutrient intake for M. sanguinipes, both in laboratory and field populations. Through this work, I found that field and lab populations can exhibit different protein (p) to carbohydrate (c) ratios, or Intake Targets (ITs), but that the field populations had ITs that matched the nutrients available in their environment. I also used the GFN to show that infections with the fungal entomopathogen Metarhizium robertsii DWR2009 did not alter ITs in M. sanguinipes. Although, when confined to carbohydrate- or protein-biased diets, infected grasshoppers had a slightly extended lifespan relative to grasshoppers fed balanced protein:carbohydrate diets. Interestingly, in a postmortem for the grasshopper, the fungus was only able to effectively sporulate on grasshoppers fed the 1p:1c diets, suggesting that grasshopper diet can have substantial impacts on the spread of fungal biopesticides throughout a population, in the absence of any inhibitory abiotic factors. Lastly, I examined the major barriers to fungal and microsporidian biopesticide usage in the United States, including low efficacy, thermal and environmental sensitivity, non-target effects, unregistered or restricted use, and economic or accessibility barriers. I also explored potential solutions to these challenges. This dissertation's focus on Melanoplus sanguinipes and Metarhizium roberstii Strain DWR2009, generates new information about how nutritional physiology and immunology intersect to impact M. sanguinipes performance. The methodology in each of the experimental chapters provides a framework for examining other problematic grasshopper species, by determining baseline nutritional physiology, and coupling nutrition with immunology to maximize the effectiveness of biological pesticides.
ContributorsZembrzuski, Deanna (Author) / Cease, Arianne (Thesis advisor) / Harrison, Jon (Committee member) / Angilletta, Michael (Committee member) / Jaronski, Stefan (Committee member) / Arizona State University (Publisher)
Created2023
Description

Due to what is known as the “biologically desert fallacy” and the pervasive westernized ideal of wilderness that has influenced widespread American Conservation culture for millennia, urban areas have long been deemed as areas devoid of biodiversity. However, cities can contribute significantly to regional biodiversity and provide vital niches for

Due to what is known as the “biologically desert fallacy” and the pervasive westernized ideal of wilderness that has influenced widespread American Conservation culture for millennia, urban areas have long been deemed as areas devoid of biodiversity. However, cities can contribute significantly to regional biodiversity and provide vital niches for wildlife, illuminating the growing awareness that cities are crucial to the future of conservation and combating the global biodiversity crisis. In terms of the biodiversity crisis, bats are a relevant species of concern. In many studies, different bat species have been broadly classified according to their ability to adapt to urban environments. There is evidence that urban areas can filter bat species based on traits and behavior, with many bats possessing traits that do not allow them to live in cities. The three broad categories are urban avoiders, urban adapters, or urban exploiters based upon where their abundance is highest along a gradient of urban intensity. A common example of an urban exploiter bat is a Mexican Free-tailed bat, which can thrive and rely on urban environments and it is found in the Phoenix Metropolitan area. Bats are important as even in urban environments they play vital ecological roles such as cactus pollination, insect management, and seed dispersal. Bat Crazy is a thesis project focused on urban enhancement and the field of urban biodiversity. The goals of this thesis are to observe how bio-conscious urban cities that work to promote species conservation can serve as a positive tool to promote biodiversity and foster community education and engagement for their urban environment.

ContributorsKaiser, Nicole (Author) / Senko, Jesse (Thesis director) / Angilletta, Michael (Committee member) / Lynch, John (Committee member) / Barrett, The Honors College (Contributor) / School of International Letters and Cultures (Contributor) / School of Life Sciences (Contributor)
Created2023-05
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There is considerable recent interest in the dynamic nature of immune function in the context of an animal’s internal and external environment. An important focus within this field of ecoimmunology is on how availability of resources such as energy can alter immune function. Water is an additional resource that drives

There is considerable recent interest in the dynamic nature of immune function in the context of an animal’s internal and external environment. An important focus within this field of ecoimmunology is on how availability of resources such as energy can alter immune function. Water is an additional resource that drives animal development, physiology, and behavior, yet the influence hydration has on immunity has received limited attention. In particular, hydration state may have the greatest potential to drive fluctuations in immunity and other physiological functions in species that live in water-limited environments where they may experience periods of dehydration. To shed light on the sensitivity of immune function to hydration state, I first tested the effect of hydration states (hydrated, dehydrated, and rehydrated) and digestive states on innate immunity in the Gila monster, a desert-dwelling lizard. Though dehydration is often thought to be stressful and, if experienced chronically, likely to decrease immune function, dehydration elicited an increase in immune response in this species, while digestive state had no effect. Next, I tested whether dehydration was indeed stressful, and tested a broader range of immune measures. My findings validated the enhanced innate immunity across additional measures and revealed that Gila monsters lacked a significant stress hormone response during dehydration (though results were suggestive). I next sought to test if life history (in terms of environmental stability) drives these differences in dehydration responses using a comparative approach. I compared four confamilial pairs of squamate species that varied in habitat type within each pair—four species that are adapted to xeric environments and four that are adapted to more mesic environments. No effect of life history was detected between groups, but hydration was a driver of some measures of innate immunity and of stress hormone concentrations in multiple species. Additionally, species that exhibited a stress response to dehydration did not have decreased innate immunity, suggesting these physiological responses may often be decoupled. My dissertation work provides new insight into the relationship between hydration, stress, and immunity, and it may inform future work exploring disease transmission or organismal responses to climate change.
ContributorsMoeller, Karla T (Author) / DeNardo, Dale (Thesis advisor) / Angilletta, Michael (Committee member) / French, Susannah (Committee member) / Rutowski, Ronald (Committee member) / Sabo, John (Committee member) / Arizona State University (Publisher)
Created2016
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Why do many animals possess multiple classes of photoreceptors that vary in the wavelengths of light to which they are sensitive? Multiple spectral photoreceptor classes are a requirement for true color vision. However, animals may have unconventional vision, in which multiple spectral channels broaden the range of wavelengths that can

Why do many animals possess multiple classes of photoreceptors that vary in the wavelengths of light to which they are sensitive? Multiple spectral photoreceptor classes are a requirement for true color vision. However, animals may have unconventional vision, in which multiple spectral channels broaden the range of wavelengths that can be detected, or in which they use only a subset of receptors for specific behaviors. Branchiopod crustaceans are of interest for the study of unconventional color vision because they express multiple visual pigments in their compound eyes, have a simple repertoire of visually guided behavior, inhabit unique and highly variable light environments, and possess secondary neural simplifications. I first tested the behavioral responses of two representative species of branchiopods from separate orders, Streptocephalus mackini Anostracans (fairy shrimp), and Triops longicaudatus Notostracans (tadpole shrimp). I found that they maintain vertical position in the water column over a broad range of intensities and wavelengths, and respond behaviorally even at intensities below those of starlight. Accordingly, light intensities of their habitats at shallow depths tend to be dimmer than terrestrial habitats under starlight. Using models of how their compound eyes and the first neuropil of their optic lobe process visual cues, I infer that both orders of branchiopods use spatial summation from multiple compound eye ommatidia to respond at low intensities. Then, to understand if branchiopods use unconventional vision to guide these behaviors, I took electroretinographic recordings (ERGs) from their compound eyes and used models of spectral absorptance for a multimodel selection approach to make inferences about the number of photoreceptor classes in their eyes. I infer that both species have four spectral classes of photoreceptors that contribute to their ERGs, suggesting unconventional vision guides the described behavior. I extended the same modeling approach to other organisms, finding that the model inferences align with the empirically determined number of photoreceptor classes for this diverse set of organisms. This dissertation expands the conceptual framework of color vision research, indicating unconventional vision is more widespread than previously considered, and explains why some organisms have more spectral classes than would be expected from their behavioral repertoire.
ContributorsLessios, Nicolas (Author) / Rutowski, Ronald L (Thesis advisor) / Cohen, Jonathan H (Thesis advisor) / Harrison, John (Committee member) / Neuer, Susanne (Committee member) / McGraw, Kevin (Committee member) / Arizona State University (Publisher)
Created2016