Biology Commons^™

Cryptic Diversification Of Two Widespread Species In Madagascar, Lynika Sharlice Strozier

Master's Theses

Using phylogenetic and phylogeographic tools to uncover hidden diversity within the genus Newtonia in Madagascar

Madagascar is known for its rich biodiversity and high level of endemic species that are found nowhere else. Cryptic diversification, defined as genetically and evolutionarily distinct species that are hard to detect because they are morphologically indistinguishable from their closest relatives, has been hypothesized to occur in many groups on Madagascar. Currently it is unclear to what extent this phenomenon occurs in birds because only a few studies have been conducted. My study examined the phylogenetic and phylogeographic patterns within a songbird genus, Newtonia, that …

The Role Of Orphan Nuclear Receptor Dax-1 (Nr0b1) In Human Breast Cancer Cells: Expression, Proliferation And Metastasis, Erin Dishington

Master's Theses

The orphan nuclear hormone receptor DAX-1 (Dosage Sensitive Sex Reversal, Adrenal Hypoplasia Congenita on the X Chromosome, gene 1) plays an important role in the development of adrenal and gonadal tissues and functions as a global negative-regulator of steroidogenesis. In addition, it is known to be involved in several diseases including some cancers. Herein, we describe our examination of the role of DAX-1 in breast cancer, specifically its influence on proliferation and metastasis and its expression during progressive stages of disease. In an effort to understand how DAX-1 influences breast cancer cell proliferation and metastasis, we used MCF7 breast cancer …

Proteomic Analysis Of The Crustacean Molting Gland (Y-Organ) Over The Course Of The Molt Cycle, Talia B. Head

Master's Theses

Molting in crustaceans is a highly complex physiological process involving negative regulation by two paired endocrine glands, the X-organ/sinus gland complex (XO/SG) and the Y-organ (YO). The XO/SG complex is responsible for making molt-inhibiting hormone (MIH) which negatively regulates synthesis of the molting hormones, ecdysteroids, by the YO. Analysis of gene expression in the XOs and YOs has led to the development of a proposed molecular signaling pathway which regulates ecdysteroidogenesis and subsequent molting in crustaceans. In this study, changes in protein abundance in the YO were characterized over the course of a molt cycle (intermolt, early premolt, mid premolt, …

Effects Of Wave Action On The Structure Of Fish Assemblages Across An Exposure Gradient, Lauren Liddon

Master's Theses

Disturbance affects the function and diversity of ecosystems. Increased wave exposure to salt marsh can disturb sediments and cause a loss of habitat. The purpose of this study was to explore the effects of increased wave exposure on diversity, abundance, and functional ecology of estuarine fishes. If increased wave exposure is acting as a disturbance to these habitats, ecological theory (Intermediate Disturbance Hypothesis) predicts that diversity will peak at intermediate frequencies and intensities of disturbance. Fish were sampled from 10 sites monthly for 6 years. The sites were assigned to different exposure categories (Open, Intermediate, and Sheltered) using an exposure …

Effects Of Food Consumption On Cell Proliferation In The Brain Of Python Regius, Stacy Star Habroun

Master's Theses

Neurogenesis is an important and vastly under-explored area in reptiles. While the ability to generate new brain cells in the adult mammalian brain is limited, reptiles are able to regenerate large populations of neuronal cells. Pythons exhibit a characteristic specific dynamic action (SDA) response after food intake with an increase in metabolic rate that facilitates processing the meal. Associated with this change in SDA, pythons (Python spp.) also exhibit impressive plasticity in their digestive and cardiovascular physiology due to the sheer magnitude of the increase in organ growth that occurs after a meal to speed digestion, absorption, and assimilation of …

The Population Genetics Of Morro Bay Eelgrass (Zostera Marina), Julia Gardner Harencar

Master's Theses

Seagrass populations are in decline worldwide. Zostera marina (eelgrass), one of California’s native seagrasses, is no exception to this trend. In the last 8 years, Morro Bay, California has lost 95% of its eelgrass. Eelgrass is an ecosystem engineer, providing important ecosystem services such as sediment stabilization, nutrient cycling, and nursery habitats for fish. The failure of recent restoration efforts necessitates a better understanding of the causes of eelgrass decline in this estuary. Previous research on eelgrass in California has demonstrated a link between population genetic diversity and eelgrass bed health, ecosystem functioning, and resilience to disturbance and extreme climatic …

West Indian Manatee (Trichechus Manatus) Habitat Characterization Using Side-Scan Sonar, Mindy J. Mclarty

Master's Theses

In this study, the reliability of low cost side-scan sonar to accurately identify soft substrates such as grass and mud was tested. Benthic substrates can be hard to classify from the surface, necessitating an alternative survey approach. A total area of 11.5 km² was surveyed with the sonar in a large, brackish mangrove lagoon system. Individual points were ground-truthed for comparison with the sonar recordings to provide a measure of accuracy. Five substrate types were identified: Dense seagrass, sparse seagrass, mangrove soil, mangrove soil with rock, and silt. A zoned benthic substrate map was created from the sonar recordings. …

Glaucous-Winged Gull Predation On Chicken Eggs Treated With A Uv-Blocking Agent, Athena T. Smith

Master's Theses

Egg cannibalism plays a major role in the life histories of Glaucous-winged Gulls (Larus glaucescens) breeding at Protection Island, Washington. Gulls, along with other birds, visualize reflected ultraviolet (UV) light and I wondered if reflected UV light plays a role in determining which eggs are selected for cannibalization. Motivated by studies showing that tree-nesting bird eggs coated with a UV-blocking agent were less subject to predation than control eggs, I tested whether ground-nesting Glaucous-winged Gulls would preferentially predate control chicken eggs over those coated with a UV-blocking agent. Early during five mornings I formed artificial nests at randomly-determined …

The Effects Of Treating Multispecies Biofilms With Bacteriophage, Alexandria Francis Cooper

Master's Theses

Biofilms can be found in any environment within proximity to water and are problematic in an assortment of industries. Numerous efforts have been employed to dislodge biofilms including bacteriophages (viruses that infect bacteria). Phage remediation is a promising solution for combatting biofilms that form on catheters in long term use patients. These biofilms often result in catheter-associated urinary tract infections (CAUTIs) and are the most common type of healthcare related infection reported. Additionally, they result in longer hospital stays and increased morbidity. To date, most of the research on the topic focuses on single species biofilms, despite their rarity in …

The Response Of A Predatory Fish, Ophiodon Elongatus, To A Marine Protected Area: Variation In Diet, Catch Rates, And Size Composition, Eric S. Anderson

Master's Theses

Marine Protected Areas (MPAs) are a management tool used to protect and sustain many ecologically and economically important fish species from overexploitation by recreational and commercial fishing. Lingcod (Ophiodon elongatus) and some of its prey species, such as rockfish (Sebastes spp.), are species that are protected from fishing in some California MPAs. Lingcod is an apex predator that consumes a variety of fish and invertebrate species. In this study, I sought to assess the effect of an MPA on the abundance, size and diet of Lingcod. I hypothesized that Lingcod in a no-take MPA would be more …

The Importance Of The Multicomponent Display In Sexual Selection Of Black Morph Girardinus Metallicus (Pisces: Poeciliidae), Erin M. Wojan

Master's Theses

Multicomponent displays are composed of traits, such as coloration, structural ornaments, and behavior, that become integrated and signal information to conspecifics. Estimation of multicomponent displays in fishes often involves measurement of color traits. Fish color measurements are often obtained following immobilization via chemical anesthesia; however, the anesthetics may alter the resulting measurements, for example by darkening the skin. Girardinus metallicus, a poeciliid fish endemic to Cuba, has a multicomponent courtship and aggressive display. Black morph males exhibit black ventral coloration including the gonopodium (copulatory organ) and yellow in the non-black areas of their bodies. I investigated the effects of …

Effect Of Oxygen-Limiting Tidal Conditions On Muscle Metabolism And Structure In The Giant Acorn Barnacle, Balanus Nubilus, Katie O. Grady

Master's Theses

Crustacean muscle fibers are some of the largest cells in the animal kingdom, with fiber diameters in the giant acorn barnacle (Balanus nubilus) exceeding 3 mm. Sessile animals with extreme muscle sizes and that live in the hypoxia-inducing intertidal zone – like B. nubilus – represent ideal models for probing the effects of oxygen limitation on muscle cells. We investigated changes in metabolism and structure of B. nubilus muscle in response to: normoxic immersion, anoxic immersion, or air emersion, for acute (6h) or chronic (6h exposures twice daily for 2wks) time periods. Following exposure, we immediately measured hemolymph …

Circadian And Circatidal Rhythms Of Protein Abundance In The Intertidal Mussel Mytilus Californianus, Cory Elowe

Master's Theses

The intertidal zone is a dynamic environment that fluctuates with the 12.4-h tidal and 24-h light/dark cycle to predictably alter food availability, temperature, air exposure, wave action, oxygen partial pressure, and osmotic conditions. Intertidal sessile bivalves exhibit behavioral or physiological changes to minimize the persistent challenges of fluctuating environmental conditions, such as adjusting gaping behavior and heart rate. At the cellular level, transcriptomic studies on mussels’ baseline circadian and circatidal rhythms have determined that the circadian rhythm is the dominant transcriptional rhythm. However, as proteins reflect the basic molecular phenotype of an organism and their abundance may differ greatly from …

The Elasmobranch-Microbe Relationship: Trimethylamine N-Oxide Synthesis, Urea Hydrolysis, And Microbe-Osmolyte Interactions In The Atlantic Stingray, Dasyatis Sabina, Kaitlin Kelly Doucette

Master's Theses

The elasmobranch osmoregulatory strategy is predicated on the accumulation of nitrogenous compounds, primarily urea and trimethylamine n¬-oxide (TMAO). Despite the abundance of these plasma osmolytes, it is notable that elasmobranchs appear to lack urease and TMA oxidase (Tmase), enzymes that scavenge urea-nitrogen and synthesize TMAO, respectively. However, urease and Tmase are found in many species of bacteria. Therefore, I hypothesized that intestinal bacteria are responsible for urease and Tmase activity in elasmobranchs. Absent dietary nitrogen sources, I evaluated the effects of reduced intestinal microbiota on osmoregulation in Atlantic stingray (Dasyatis sabina) in vivo. D. sabina were given …

Fecal Bacterial Communities As An Indicator Of Trophic Interactions Among Anuran Larvae, Steven Jacob Everman

Master's Theses

Anurans are mass spawners, often with multiple females spawning together, resulting in thousands of tadpoles sharing a habitat. Such large numbers of tadpoles with limited dispersal can lead to intense competition for resources. Inter and intra-specific competition for food could have negative impacts on the growth and survival of smaller tadpoles. Fecal bacterial communities have the potential to be used as indicators of changes in diet making it possible to determine if tadpoles in the wild are eating the same food or not. After feeding on two prepared diets that differed in the percentage of complex carbohydrates, the fecal bacterial …

Bloom Or Bust: Retrospective Analysis Of The Giant Jellyfish, Nemopilema Nomurai (Scyphozoa: Rhizostomeae), Ecology In The East Asian Marginal Seas, Naomi Yoder

Master's Theses

The Giant Jellyfish, Nemopilema nomurai, is a large-bodied bloom-forming jellyfish that occurs in the semi-enclosed basins of the East Asian Marginal Seas. N. nomurai has bloomed more frequently in the past 20 years than in any period previously recorded. In Japan, recent N. nomurai blooms were responsible for millions of dollars in lost revenue and equipment damage to commercial fisheries alone. This study statistically analyzed 21 environmental factors in connection with N. nomurai occurrence (using occurrence as a proxy for blooms). Eight factors resulted in a statistically significant or marginally significant (p ≤ 0.10), linear or non-linear relationship with …

Gulf Sturgeon (Acipenser Oxyrinchus Desotoi) Pre-Restoration Occupancy Patterns On Ship Island, Mississippi Sound With An Evaluation Of Designated Critical Habitat Use By Eastern And Western Population Segments, Page Elizabeth Vick

Master's Theses

Critical spawning and feeding habitat was designated for federally threatened, anadromous Gulf Sturgeon (GS) to aid in population recovery. This study examined GS occupancy, habitat use, and movement through critical habitat monitored by the Ship Island (SI) acoustic array during overwintering periods from 2011 to 2015 prior to MsCIP SI restoration. An occupancy index analyzed patterns of spatial and temporal habitat use of both western and eastern population segments (WPS and EPS, respectively) of GS on the SI array. The ends of SI along with the passes and cuts of the island, especially Dog Keys Pass (DKP), were occupied by …

The Effects Of 4-Nonylphenol On The Immune Response Of The Pacific Oyster, Crassostrea Gigas, Following Bacterial Infection (Vibrio Campbellii), Courtney Hart

Master's Theses

Endocrine disrupting chemicals (EDCs) are compounds that can interfere with hormone signaling pathways and are now recognized as pervasive in estuarine and marine waters. One prevalent EDC in California’s coastal waters is the xenoestrogen 4-nonylphenol (4-NP), which has been shown to impair reproduction, development, growth, and in some cases immune function of marine invertebrates. To further investigate effects of 4-NP on marine invertebrate immune function we measured total hemocyte counts (THC), relative transcript abundance of immune-relevant genes, and lysozyme activity in Pacific oysters (Crassostrea gigas) following bacterial infection. To quantify these effects we exposed oysters to dissolved phase …

Community Structure And Production Of The Macrobenthos On Four Artificial Reefs In The Mississippi Sound In Relation To Substrate And Profile Type, Patrick Daniel Gillam

Master's Theses

In recent years, the Mississippi Department of Marine Resources (DMR) has made a concerted effort to enhance its coastal fishery resources by creating artificial reefs. Through this effort, 73 nearshore reefs have been created across the MS coast. Different substrate types used to construct MS artificial reefs include oyster shell and cement rubble. Two types of reef architecture used include high profile breakwater and low profile submerged structures. This study compared the benthic biota associated with oyster shell and cement rubble substrates among four artificial reefs representing high and low profile structures in summer 2011. Colonized benthic biota were quantified …

Effects Of Fire On Soil Co₂ Efflux In A Mature Longleaf Pine Forest, Knox Lemee Flowers

Master's Theses

This study was conducted from 2012-2013 in a 96 year old longleaf pine at the Lake Thoreau Environmental Center located Lamar County, MS. Measurements of soil CO₂ efflux (i.e., soil respiration or SR) rates (µmol m^-2 sec^-1) were taken across 8 field plots (4 burned, 4 unburned) before and after a prescribed fire on that occurred in May, 2012. These measurements were taken over diurnal cycles using a LICOR LI-8100A automated soil gas flux system with long term chambers. SR rates and soil temperature measurements were collected during 3 sampling periods in 2012 and 1 sampling period …

Evaluating The Myth Of Allelopathy In California Blue Gum Plantations, Kristen Marie Nelson

Master's Theses

It is widely accepted that allelopathy is not only significant, but more or less singular, in the inhibition of understory vegetation in California Eucalyptus globulus (blue gum) plantations. However, there is no published documentation of allelopathy by blue gums against California native species. Here, we present evidence that germination and early seedling growth of five California native species are not inhibited by chemical extracts of blue gum foliage, either at naturally-occurring or artificially concentrated levels. In the greenhouse, seeds were germinated in field-collected soil from mature blue gum plantations and the adjacent native, coastal scrub communities. In petri plates, seeds …

Evaluation Of The Estrogenic And Osmoregulatory Impacts Of Exposure To 4-Nonylphenol Pollution In The Estuarine Arrow Goby, Clevelandia Ios, Kaitlin Marie Johnson

Master's Theses

Recent evidence indicates that some of California’s coastal estuaries are contaminated with the chemical 4-nonylphenol (4-NP). Tissue burdens of 4-NP detected in the intertidal arrow goby (Clevelandia ios) in California are among the highest recorded worldwide, however, it remains unknown whether these fish are impacted by this 4-NP contamination. 4-NP is an established endocrine disrupting compound with estrogenic properties that can alter reproductive function. Furthermore, evidence that estrogens can modulate iono- and osmo-regulatory function in fishes implies that estuarine fishes exposed to 4-NP may also experience an impaired ability to maintain hydromineral balance. In Chapter 1 of this …

Assessing The Success Of Outreach At Preventing The Movement Of Aquatic Invasive Species In Illinois, Ellen Anne Cole

Master's Theses

Overland transport of recreational boats is the major vector of dispersal for aquatic invasive species among North American waterbodies. These species have large economic and ecosystem impacts, and understanding their movement is essential to understanding the biodiversity and functioning of aquatic ecosystems across the continent. I surveyed Illinois boaters to determine patterns of recreational boat movement and the consistency with which boaters perform actions to prevent the spread of invasive species. Although most boaters perform these actions, a large minority do not and the network for invasive species spread on recreational boats still connects most waterbodies. Next, I interviewed managers …

Chronic Toxicity Of Binary Metal Mixtures Of Cadmium-Zinc And Cadmium-Nickelon Daphnia Magna, Edgar Ramiro Perez

Master's Theses

This study characterizes binary-metal mixture effects of cadmium (Cd2+) + zinc (Zn2+) and Cd2+ + nickel (Ni2+) on Daphnia magna. Although acute studies have shown protective Ni2+ (Traudt et al. 2016) and Zn2+ effects (Meyer et al. 2015) against Cd2+ toxicity, no study has fully characterized a protective effect on D. magna at several endpoints (survival, reproduction, growth, and accumulation) on a chronic study. In this study, the titration design was selected to characterize the 21 day (21-d) chronic effects of the binary-metal mixtures on survival, growth, reproduction, and metal accumulation in D. magna. Using this design, increasing concentrations of …

Production And Harvest Of Microalgae In Wastewater Raceways With Resource Recycling, Alexander Colin Roberts

Master's Theses

Microalgae can be grown on municipal wastewater media to both treat the wastewater and produce feedstock for algae biofuel production. However the reliability of treatment must be demonstrated, as well as high areal algae productivity on recycled wastewater media and efficient sedimentation harvesting. This processes was studied at pilot scale in the present research.

A pilot facility was operated with nine CO₂-supplemented raceway ponds, each with a 33-m² surface area and a 0.3-m depth, continuously from March 6, 2013 through September 24, 2014. The ponds were operated as three sets of triplicates with two sets continuously fed …

Gut Microbiota Of Migratory Passerines At Stopover, William Bagley Lewis

Master's Theses

Although the gut microbiota provides many beneficial functions to animal hosts, relatively little is known about the gut microbiota of passerines. It is likely that gut microbes are especially important during the migratory phase; however gut atrophy experienced during prolonged migratory flight may cause disruptions of the stable microbiota. Fecal samples were collected from several species of passerine after crossing the Gulf of Mexico during spring migration and before crossing during fall, and microbiota communities were analyzed using next-generation sequencing. Despite showing large inter-individual variation, a core microbiota composed largely of Firmicutes and Proteobacteria was identified in all birds. Microbiota …

The Vascular Flora Of Wayne County, Mississippi, Daniel M. Mcnair

Master's Theses

The vascular flora of Wayne County, Mississippi, was surveyed from 2013–2015, and the species of native and naturalized plants are listed. In total, 1,135 species were identified from field collections, previously collected herbarium specimens, and field observations. These belong to 556 genera and 165 families. Four of these species represent first recorded occurrences in the state of Mississippi: Blyxa aubertii Rich., Gomphrena serrata Pav. ex Moq., Isoetes valida (Engelm.) Clute, and Polypogon interruptus Kunth. GPS coordinates are given for important collection sites representing the diversity of plant communities in the county. All voucher specimens from the survey are deposited in …

High Resolution Melt Analysis Of Samples With Differential Dna Methylation To Identify Tissue Source Of Origin, Stephanie M. Ledgerwood

Master's Theses

In Forensic Science casework, identifying the source of a tissue can assist in crime scene reconstruction. Currently, presumptive testing methods to identify tissue type are utilized in crime scene laboratories, but there is a need for a more reliable confirmatory test for tissue type identification. High Resolution Melt (HRM) analysis is an innovative technology that has the potential to determine tissue types through variations in DNA methylation patterns. Recently, DNA methylation patterns have been found to correspond with specific tissue types in particular regions of DNA. Two markers, B_SPTB_03 and DDX4 have been effective in differentiating sperm from other tissue …

Maternal Effects And Offspring Behavior: Potential Contributors To The Lack Of Recruitment In Mississippi Gopher Tortoises (Gopherus Polyphemus), Aaron L. Holbrook

Master's Theses

Federally threatened in Mississippi, gopher tortoise (Gopherus polyphemus) populations within the state have strongly variable recruitment and are generally in decline. Hatching success is significantly lower in Mississippi than in any other part of the species’ range , and most hatchlings die within the first year. There are few refuges where survival and hatching success is high. Here I compare two populations that differ in recruitment and offspring survival for differences in corticosterone. Corticosterone is a hormone that influences both energy availability and is released in elevated levels during stressful events, like living in poor quality habitat. Prolonged corticosterone elevation …

Lyme Disease Ecology In San Luis Obispo County: The Role Of The Western Gray Squirrel, Ryan William Baker-Branstetter

Master's Theses

Despite the fact that eight cases of Lyme disease were diagnosed in San Luis Obispo County between 2005-2013, the identity of wildlife hosts serving as sources for tick infection in this region remained unidentified. The primary cause of Lyme disease in the U.S. is the spirochetal bacterium Borrelia burgdorferi sensu stricto, and this agent had not been previously isolated from the region. Borrelia bissettii, a related species that has not been implicated as a common causative agent of Lyme disease, was isolated in small rodents inhabiting coastal scrub and chaparral habitats in a previous San Luis Obispo County study. However, …