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Spatial And Temporal Dynamics Of Batesian Mimicry Between Adelpha Californica And Limenitis Lorquini, Louis Albert Prusa
Spatial And Temporal Dynamics Of Batesian Mimicry Between Adelpha Californica And Limenitis Lorquini, Louis Albert Prusa
University of the Pacific Theses and Dissertations
Conspicuous coloration is one of the main ways that animals communicate. The use of eye-catching color patterns to warn predators of an unprofitable trait is referred to as aposematism. Once predators learn to recognize the color pattern, a new signaling niche becomes available where other species can share the same signal. This mimicry niche can involve a “hide in plain sight” strategy by mimicking or parasitizing this signal, with mimics lacking the defense and associated costs that make them unprofitable. This is termed Batesian mimicry, and it decreases predation by taking advantage of the memory and learning of the predator …
Unknown And Cryptic Diversity In The Adelpha Serpa-Group, Cassidi Rush
Unknown And Cryptic Diversity In The Adelpha Serpa-Group, Cassidi Rush
University of the Pacific Theses and Dissertations
The tropics are host to incredible insect diversity. One of the most charismatic groups that exhibit this diversity are the butterflies. Despite the tropical butterfly fauna being heavily researched, there remains much hidden diversity in the form of undescribed life histories and cryptic species. This is especially true among the species rich Nymphalidae, the brush-footed butterflies. Species in the genus Adelpha are known to be “the most trying taxonomically of all nymphalids” DeVries (1987), and as such are fruitful ground for uncovering unknown diversity. About half of the species within Adelpha have undescribed life histories, while A. serpa stands out …
Neuromuscular Control Of The Calling Apparatus In The Túngara Frog (Engystomops Pustulosus), Kiran Kaur Grewal
Neuromuscular Control Of The Calling Apparatus In The Túngara Frog (Engystomops Pustulosus), Kiran Kaur Grewal
University of the Pacific Theses and Dissertations
Male túngara frogs can add a distinctive note ("chuck”) to their mating call. Production of the chuck involves vibrating a pair of laryngeal fibrous masses that is attached to the vocal cords. The muscular control of this mechanism remains unknown. Recent studies revealed a split in the laryngeal dilator muscle, which unveiled the deep dilator as a novel laryngeal muscle with unique attachments, innervation, and (likely) function. The deep dilator may position the fibrous masses for chuck production. The goals of this study were 1) to confirm the innervation of the novel muscle through electrophysiology; and 2) to determine the …
Endocrine Responses To Repeated Adrenocorticotropic Hormone Administration In Free-Ranging Elephant, Molly Mccormley
Endocrine Responses To Repeated Adrenocorticotropic Hormone Administration In Free-Ranging Elephant, Molly Mccormley
University of the Pacific Theses and Dissertations
Understanding the physiological response of marine mammals to anthropogenic stressors can inform marine ecosystem conservation strategies. Stress stimulates release of glucocorticoid (GC) hormones, which increase energy substrate availability while suppressing energy-intensive processes. Exposure to repeated stressors can potentially affect an animal’s ability to respond to and recover from subsequent challenges. To assess the endocrine response of a marine mammal to repeated stressors, we administered adrenocorticotropic hormone (ACTH) to free-ranging juvenile northern elephant seals (Mirounga angustirostris; n=7) once daily for four days. ACTH administration induced significant, but transient (<24 h) elevation in circulating cortisol levels (p < 0.0001). These increases did not vary in magnitude between the first ACTH challenge on day 1 and the last challenge on day 4. In contrast, aldosterone levels remained elevated above baseline for at least 24 hours after each ACTH injection (p < 0.001), and responses were greater on day 4 than day 1 (p < 0.01). Total triiodothyronine (tT3) levels were decreased on day 4 relative to day 1 (p < 0.01), while reverse triiodothyronine (rT3) concentrations increased relative to baseline on days 1 and 4 (p < 0.001) in response to ACTH, indicating a suppression of thyroid hormone secretion. There was no effect of ACTH on the sex steroid dehydroepiandrosterone (DHEA). These results suggest that elephant seals are able to mount adrenal responses to multiple ACTH challenges. However, repeated stress results in facilitation of aldosterone secretion and suppression of tT3, which may impact osmoregulation and metabolism. We propose that aldosterone and tT3 are informative additional indicators of repeated stress in marine mammals.
Evidence That A Partner-Switching Regulatory System Modulates Hormogonium Motility In The Filamentous Cyanobacterium Nostoc Punctiforme, Kelsey Wynne Riley
Evidence That A Partner-Switching Regulatory System Modulates Hormogonium Motility In The Filamentous Cyanobacterium Nostoc Punctiforme, Kelsey Wynne Riley
University of the Pacific Theses and Dissertations
Partner-switching regulatory systems (PSRSs) are utilized by many different bacteria to regulate a wide array of cellular responses, from stress response to expression of virulence factors. The filamentous cyanobacterium Nostoc punctiforme can transiently differentiate motile filaments, called hormogonia, in response to various changes in the environment. Hormogonia utilize a Type IV pilus (T4P) complex in conjunction with a secreted polysaccharide for gliding motility along solid surfaces. This study identified three genes, designated hmpU, hmpW, and hmpV, encoding the protein components of a PSRS involved in regulation of hormogonium motility in N. punctiforme. Although mutant strains with in-frame deletions in hmpU, …