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Modeling An Electrosensory Landscape: Behavioral And Morphological Optimization In Elasmobranch Prey Capture, Brandon R. Brown

Physics and Astronomy

Most biological sensory systems benefit from multiple sensors. Elasmobranchs (sharks, skates and rays) possess an array of electroreceptive organs that facilitate prey location, mate location and navigation. Here, the perceived electrosensory landscape for an elasmobranch approaching prey is mathematically modeled. The voltages that develop simultaneously in dozens of separate sensing organs are calculated using electrodynamics. These voltages lead directly to firing rate modifications in the primary afferent nerves. The canals connecting the sense organs to an elasmobranch's surface exhibit great variation of location and orientation. Here, the voltages arising in the sense organs are found to depend strongly on the …

Characterization Of The Autotrophic Component In Periphyton Upon Typha Angustifolia Detritus In A Freshwater Wetland, Eric J. Warda

Master's Theses and Doctoral Dissertations

The autotrophic component of periphyton on Typha angustifolia detritus was characterized in a freshwater wetland during a single growing season. 58 genera of algae and cyanobacteria, representing six divisions, were observed throughout the study period. Although the combined algae-cyanobacteria density from within and outside the Typha stands were significantly affected by both sample date and the combination of date and location, no significant differences occurred in biovolume. Similarly, no clear evidence of successional patterns was observed.

Although few significant interactions were observed, Typha detritus provided a substratum for vast numbers and biomass of periphyton. A combined density for the observed …

Reproductive Effort, Offspring Size And Benefit/Cost Ratios In The Classification Of Life Histories, Eric Charnov

Biology Faculty & Staff Publications

There have been many attempts to document links between reproductive allocation and factors such as adult body size and demography. This paper suggests that among closely related taxa, two dimensionless numbers, each a benefit—cost ratio summarizing reproductive timing, allocation and demography, are invariants and thus are useful to classify life histories. The two numbers are E/α and C·E, where E is average adult life span,α is age-at-first-reproduction and C is average mass (per adult) devoted to reproduction per unit of time, divided by the average adult body mass (m); C is usually called reproductive effort'. Since E−1 is the average …

Anti-Predation Does Not Fully Explain Grouping In The Chinese Water Deer (Hydropotes Inermis), Lixing Sun

Biology Faculty Scholarship

The grouping behavior of the Chinese water deer (Hydropotes inermis) was studied at Poyang Lake National Nature Reserve, Jiangxi, China. I made three predictions to test the hypothesis that grouping is an anti-predatory strategy: (1) group size is negatively related to vegetation cover, (2) animals in groups have more time to feed than solitary animals, and (3) animals spend less time in vigilance when they are in groups than when they are alone. Results showed that group size was largest in the mating season and smallest in the parturition season. Deer tended to form larger groups when they …

Performance Limits Of Labriform Propulsion And Correlates With Fin Shape And Motion, Jeffrey A. Walker Phd, Mark W. Westneat

Faculty Publications

Labriform locomotion, which is powered by oscillating the paired pectoral fins, varies along a continuum from rowing the fins back and forth to flapping the fins up and down. It has generally been assumed (i) that flapping is more mechanically efficient than rowing, a hypothesis confirmed by a recent simulation experiment, and (ii) that flapping should be associated with wing-shaped fins while rowing should be associated with paddle-shaped fins, To determine whether these hypotheses and the results of the simulation experiment are consistent with natural variation, we compared the steady swimming performance (critical swimming speed) of four species of labrid …

Activation Of Central Melanocortin Pathways By Fenfluramlne, Lora K. Heisler, Michael A. Cowley, Laurence H. Tecott, Wei Fan, Malcolm J. Low, James L. Smart, Marcelo Rubinstein, Jeffrey B. Tatro, Jacob N. Marcus, Henne Holstege, Charlotte E. Lee, Roger D. Cone, Joel K. Elmquist

Faculty Publications - Department of Biological & Molecular Science

D-fenfluramine (d-FEN) was once widely prescribed and was among the most effective weight loss drugs, but was withdrawn from clinical use because of reports of cardiac complications in a subset of patients. Discerning the neurobiology underlying the anorexic action of d-FEN may facilitate the development of new drugs to prevent and treat obesity. Through a combination of functional neuroanatomy, feeding, and electrophysiology studies in rodents, we show that d-FEN-induced anorexia requires activation of central nervous system melanocortin pathways. These results provide a mechanistic explanation of d-FEN's anorexic actions and indicate that drugs targeting these downstream melanocortin pathways may prove to …

A Complex, Cross-Taxon, Chemical Releaser Of Antipredator Behavior In Amphibians, Dale M. Madison, Aaron M. Sullivan, John C. Maerz, James H. Mcdarby, Jason R. Rohr

Faculty Publications - Department of Biological & Molecular Science

Prey species show diverse antipredator responses to chemical cues signaling predation threat. Among terrestrial vertebrates, the red-backed salamander, Plethodon cinereus, is an important species in the study of these chemical defenses. During the day and early evening, this species avoids rinses from garter snakes, Thamnophis sirtalis, independent of snake diet, but late at night, avoids only those rinses from garter snakes that have recently eaten P. cinereus. We tested whether the selective, late-night response requires the ingestion or injury of salamanders. In three experiments, we tested P. cinereus for their responses to separate or combined rinses from salamanders (undisturbed, distressed, …

Sex Differences And Seasonal Trade-Offs In Response To Injured And Non-Injured Conspecifics In Red-Spotted Newts, Notophthalmus Viridescens, Jason R. Rohr, Dale M. Madison, Aaron M. Sullivan

Faculty Publications - Department of Biological & Molecular Science

Injured prey often release alarm chemicals that induce antipredator behaviors in conspecifics. Injured or killed prey most likely release a wide array of chemicals in addition to alarm substances, such as sexual pheromones, which could enhance or compromise antipredator responses. Thus, damage-release cues provide an excellent opportunity to examine the influence of seasonally fluctuating sexual pheromones on antipredator behaviors. We used a series of laboratory and field experiments and meta-analysis to examine seasonal changes and sex differences in the response of red-spot-ted newts, Notophthalmus viridescens, to the odor of non-injured conspecifics and conspecific tissue extracts, the latter of which presumably …

The Ontogeny Of Chemically-Mediated Antipredator Behaviours In Newts (Notophthalmus Viridescens): Responses To Injured And Non-Injured Conspecifics, Aaron M. Sullivan, Jason R. Rohr, Dale M. Madison

Faculty Publications - Department of Biological & Molecular Science

Responses to alarm chemicals from injured prey may influence predation risk and foraging success of receivers and senders, while learning can influence the strength of these responses. Thus, it is important to know when in ontogeny prey produce and detect alarm substances and how learning shapes their response, but surprisingly little is known about either of these topics. We assessed when in the life of red-spotted newts, Notophthalmus viridescens, alarm chemicals are produced and detected by comparing adult versus eft (terrestrial juveniles) and larval responses to rinses and tissue extracts from individuals in each life-history stage. To evaluate the influence …

Phylogenetic Analysis And Review Of Panacea And Batesia Butterflies (Nymphalidae), Ryan I. Hill, Carla M. Penz, P. J. Devries

College of the Pacific Faculty Articles

Phylogenetic analysis of 53 morphological characte rs for five species of Panacea and Batesia hypochlora supports the separation of the two genera and showed that the monotypic genus Batesia is basal to Panacea. Male genitalia were Ilniform within Panacea and characters inir)f)llative for phylogeny reconstruction were restricted to wing coloration. Illustrations of adults and genitalia, a brief diagnosis, and distributions are provided le)r each species.

Ultrastructure Of The Reproductive System Of The Black Swamp Snake (Seminatrix Pygaea). Part Iii. The Sexual Segment Of The Male Kidney., David M. Sever

Scholarship and Professional Work - LAS

In mature male snakes and lizards, a distal portion of the nephron is hypertrophied in relation to its appearance in females and immature males. This sexual segment of the male kidney apparently provides seminal fluid that is mixed with sperm and released into the female cloaca during copulation. In this article, we provide the first study at the ultrastructural level of seasonal variation in the sexual segment of the kidney of a squamate, the natricine snake Seminatrix pygaea. Previous workers have indicated that the sexual segment is secretory only when the testes are spermatogenically active. The sexual segment of the …

A Baseline Assessment Of Furbearers On The Upper Coastal Plain Of Virginia, A. Scott Bellows, Joseph C. Mitchell

Virginia Journal of Science

We assessed the status of furbearing mammals on Fort A.P. Hill, Caroline County, Virginia during the 1998-1999 trapping season with the cooperation of local licensed trappers. Our analyses were based on 345 captures representing of 10 mammal species, ranging from one bobcat (Lynx rufus) to 157 beavers (Castor canadensis). Mean number of captures per 100 trap nights was 17.0. Captures varied from 11.9 to 17.9 per 100 trap nights for conibear traps and 9.7 to 18.3 per 100 trap nights for leg-hold traps. External measurements of six species were similar to those reported for other populations …

Effects Of Melatonin On Hemolymph Glucose And Lactate Concentrations In The Fiddler Crab, Uca Pugilator, Kathryn M. Dalton

Honors Theses

Melatonin (N-acetyl-5-methoxytryptamine) is an indolamine hormone produced by the pineal gland that works to regulate sleep/wake cycles and activity rhythms. The effects of melatonin in metabolism are far from understood. Melatonin was injected into the fiddler crab, Uca pugilator, to investigate the effects of melatonin on hemolymph glucose and lactate levels. Following injection at t=O, hemolymph samples were collected at t=O.5, 1.0, 1.5 and 5.0 hours. Melatonin caused a decrease in the stress response to injection and also caused delayed hyperglycemia. Melatonin-injected crabs also retained the glucose and lactate rhythymicity when compared to saline-injected crabs. Glucose and lactate rhythms followed …

Latitudinal Differentiation In The Effects Of The Toxic Dinoflagellate Alexandrium Spp. On The Feeding And Reproduction Of Populations Of The Copepod Acartia Hudsonica, Sean Colin, Hans G. Dam

Arts & Sciences Faculty Publications

Blooms of the dinoflagellate Alexandrium spp. increase in their frequency, toxicity and historical presence with increasing latitude from New Jersey (USA) to the Gaspé peninsula (Canada). Biogeographic variation in these blooms results in differential exposure of geographically separate copepod populations to toxic Alexandrium. We hypothesize that the ability of copepods to feed and reproduce on toxic Alexandrium should be higher in copepods from regions that are frequently exposed to toxic Alexandrium blooms. We tested this hypothesis with factorial common environment experiments in which female adults of the copepod Acartia hudsonica from five separate populations ranging from New Jersey to …

Induction Of Myocarditis And Valvuluitis In Lewis Rats By Different Epitopes Of Cardiac Myosin And Its Implications In Rheumatic Carditis, Jeffrey E. Galvin, Mark E. Hemric, Stanley D. Konsanke, Stephen M. Factor, Anthony Quinn, Madeleine W. Cunningham

Faculty Publications and Presentations

Immune responses against cardiac myosin and group A streptococcal M protein have been implicated in the pathogenesis of rheumatic heart disease. Although cardiac myosin is known to produce myocarditis in susceptible animals, it has never been investigated for its role in production of valvular heart disease, the most serious sequelae of group A streptococcal infection in acute rheumatic fever. In our study, cardiac myosin induced valvulitis in the Lewis rat, and epitopes responsible for production of valvulitis were located in the rod region. Human and rat cardiac myosins induced severe myocarditis in the Lewis rats as expected. A purified S2 …

Effects Of Indoleacetic Acid And Kinetin On Lipid Peroxidation Levels In Various Rat Tissues, İsmai̇l Çeli̇k, Yasi̇n Tülüce, Necati̇ Özok

Turkish Journal of Biology

This study was carried out to investigate whether plant growth regulators (PGRs) could affect lipid peroxidation (Malondialdehyde = MDA level) in erythrocyte, muscle, liver, heart and kidney tissue. Eighteen Sprague-Dawley albino rats were divided into three experimental groups: control and PGR-treated (indoleacetic acid and kinetin). Seventy-five ppm of PGRs, indoleacetic acid (IAA), and kinetin were administered orally to 6 rats ad libitum for 25 days. The hormone treatments caused different effects on the level of malondialdehyde (MDA) to those of the control rats. According to the results, while liver and kidney MDA levels were increased significantly by IAA administration in …

Subjective, Cultural, And Natural Ecology, Ursula Goodenough

Biology Faculty Research

No abstract provided.

Spinal Cord Of Lamprey, James T. Buchanan

Biological Sciences Faculty Research and Publications

No abstract provided.

The Effects Of Serotonin On Functionally Diverse Isolated Lamprey Spinal Cord Neurons, I. V. Batueva, James T. Buchanan, N. P. Veselkin, E. I. Suderevskaya, E. A. Tsvetkov

Biological Sciences Faculty Research and Publications

The experiments reported here showed that application of serotonin (5-hydroxytryptamine, 5-HT) (100 µ M) did not induce any significant current through the membranes of any of the spinal neurons studied (n = 62). At the same time, the membranes of most motoneurons and interneurons (15 of 18) underwent slight depolarization (2–6 mV) in the presence of 5-HT, which was not accompanied by any change in the input resistance of the cells. Depolarization to 10–20 mV occurred in some cells (3 of 18) of these functional groups, this being accompanied by 20–60% decreases in input resistance. The same concentration of 5-HT …

Glass Capillary Tube Feeding: A Method For Infecting Nymphal Ixodes Scapularis (Acari: Ixodidae) With The Lyme Disease Spirochete Borrelia Burgdorferi, Anne H. Broadwater, Daniel E. Sonenshine, Wayne L. Hynes, Shane Ceraul, Aravinda M. De Silva

Biological Sciences Faculty Publications

We evaluated an artificial capillary feeding method to infect nymphal Ixodes scapularis (Say) ticks with Borrelia burgdorferi, the causative agent of Lyme disease. Thirty to 70% of the nymphs were infected after feeding for 2.5 h from glass capillary tubes filled with a solution of spirochetes. Capillary infection was stable and persisted in the nymphs for at least 10 d after feeding. Capillary feeding also maintained natural vector competence patterns because I. scapularis ticks acquired infection unlike Dermacentor variablis (Say), which did not become infected. Capillary infected I. scapularis nymphs were capable of transmitting the infection to naive mice …

Embryology In Wax, Michael Dietrich

Dartmouth Scholarship

Book review of Embryos in Wax: Models from the Ziegler Studio by Nick Hopwood Whipple Museum of the History of Science, 2002.

Algal Blooms Reduce The Uptake Of Toxic Methylmercury In Freshwater Food Webs, Paul C. Pickhardt, Carol L. Folt, Celia Y. Chen, Bjoern Klaue, Joel D. Blum

Dartmouth Scholarship

Mercury accumulation in fish is a global public health concern, because fish are the primary source of toxic methylmercury to humans. Fish from all lakes do not pose the same level of risk to consumers. One of the most intriguing patterns is that potentially dangerous mercury concentrations can be found in fish from clear, oligotrophic lakes whereas fish from greener, eutrophic lakes often carry less mercury. In this study, we experimentally tested the hypothesis that increasing algal biomass reduces mercury accumulation at higher trophic levels through the dilution of mercury in consumed algal cells. Under bloom dilution, as algal biomass …

Functional Morphology And Developmental Biology Of Zebrafish: Reciprocal Illumination From An Unlikely Couple, L. Patricia Hernández, Michael J.F. Barresi, Stephen H. Devoto

Biological Sciences: Faculty Publications

Functional morphology has benefited greatly from the input of techniques and thinking from other disciplines. This has been especially productive in situations where each discipline has made significant contributions to a particular research topic. A combination of methodologies from functional morphology and developmental biology has allowed us to characterize feeding mechanics of first-feeding larval zebrafish (Danio rerio). Contrary to kinematic patterns commonly seen in adult teleosts, larval zebrafish showed no lateral abduction during the expansive phase of a suction-feeding event. Instead, dorsoventral expansion of the buccal chamber, more typical of patterns seen in primitive fishes, characterized the expansive phase. Moreover, …

Functional Requirement Of Aquaporin-5 In Plasma Membranes Of Sweat Glands, Lene N. Nejsum, Tae-Hwan Kwon, Uffe B. Jensen, Ornella Fumagalli, Jørgen Frøkiaer, Carissa M. Krane, Anil G. Menon, Landon S. King, Peter C. Agre, Søren Nielsen

Biology Faculty Publications

The distribution and function of aquaporins (AQPs) have not previously been defined in sweat glands. In this study, AQP1, AQP3, and AQP5 mRNA were demonstrated in rat paw by reverse transcription (RT)–PCR, but AQP2 and AQP4 were not. AQP1, AQP3, and AQP5 protein were confirmed in these tissues by immunoblotting. AQP1 was identified in capillary endothelial cells by immunohistochemical labeling, but not in sweat glands or epidermis. Abundant AQP3 expression was seen in basal levels of epidermis, but not in sweat glands. AQP2 and AQP4 were not observed in either skin or sweat glands. Immunohistochemical labeling revealed abundant AQP5 in …

Habitat Use Of Urban Bats In Springfield, Missouri, Sarah Jane Robertson

Graduate Theses/Dissertations

During the summers of 1998-2000, the Anabat II bat detector system was placed in a mosaic of habitats within Springfield, Missouri and surrounding rural areas in southern Missouri to compare the activity indices of nine bat species between urban and rural environments. A total of 1,876 echolocation call sequences was recorded, identified to species and analyzed; 1,066 were from 42 Springfield sites, and 810 were from 22 rural locations. For all species combined, urban bat activity tended to be higher than rural activity, but those differences were only significant at the reading taken 3 hours after sunset. Eptesicus fuscus activity …

A Survey Of The Mammals Of The Archie Carr And Pelican Island National Wildlife Refuges, Joseph S. Weidlich

Retrospective Theses and Dissertations

ABSTRACT This summarizes a study conducted on the Archie Carr (ACNWR) and Pelican Island (PINWR) National Wildlife Refuges located on the barrier island complex of southern Brevard and northern Indian River counties, Florida. Major objectives of this study were designed to 1) survey the mammals of the ACNWR and PINWR, 2) perform a small mammal population demographic study in coastal scrub and maritime hammock habitats, and 3) document a population monitoring project of Peromyscus po/ionotus niveiventris in northern Indian River County at Treasure Shores Park, within ACNWR Segment 4. A total of7,279 trap nights was compiled during the survey portion …

A Field Study Of The Northern Leopard Frog (Rana Pipiens) In The Potholes Reservoir Area, Washington, Heather Maranda Simmons

All Master's Theses

Northern Leopard Frogs (Rana pipiens) were studied in the Potholes Reservoir area in eastern Washington, which is a unique and dynamic system of ponds. The filling and drying cycles of the reservoir cause seasonal fluctuation on pond depth. My goal was to find frogs and document their use of these ponds. I conducted surveys of R. pipiens from April - September 2002.

I caught 178 R. pipiens adults and subadults throughout my field season, gathering weight and length data. I found two groups of egg masses in April, and noted their size, location and point of attachment. Findings were similar …

Complement Resistance In Agrobacterium Tumefaciens Isolates, Michael E. Mccormick

Honors Theses

The word "pathogen" ofen brings to mind morose images and other words such as "illness," "malaria," and "outbreak": words associated with animal pathogens, in particular, the ones that make us humans sick. However, some pathogens also affect another major kingdom, plants, and one of the more devastating pathogens to the plant kingdom is the bacteria Agrobacterium tumefaciens. This organism has a Type IV Secretion System that allows it to transfer a piece of t-DNA into the host cell; this DNA integrates into the eukaryotic genome and establishes in ction by utilizing the host's transcription machinery. This unique and effective means …

Cold Acclimation Strategy Is Highly Variable Among The Sunfishes (Centrarchidae), Deidra R. Tschantz, Elizabeth L. Crockett, Peter H. Niewiarowski, Richard L. Londraville

Biology Faculty Research

We tested the hypothesis that the physiological strategy for acclimating to low body temperature is similar among closely related fish. Largemouth bass (Micropterus salmoides), green sunfish (Lepomis cyanellus), bluegill sunfish (Lepomis macrochirus), black crappie (Pomonix nigromaculatus), and white crappie (Pomonix annularis), all members of the family Centrarchidae, were acclimated to 5degrees and 25degreesC. Morphometric variables (total mass, total length, organ masses) and enzyme activities (hexokinase; lactate dehydrogenase; and cytochrome oxidase in heart, liver, and muscle) were measured in 5degreesC- and 25degreesC- acclimated fish at 5degrees and 25degreesC assay temperatures. Each species displayed a distinct physiological response to cold acclimation that …

Species Richness, Latitude, And Scale-Sensitivity, S. Kathleen Lyons, Michael R. Willig

School of Biological Sciences: Faculty Publications

The latitudinal gradient of species richness is well documented for a variety of taxa in both terrestrial and aquatic environs. Moreover, a number of recent attempts to assess the effects of scale on the relationship have concluded that the latitudinal pattern is scale-invariant. Nonetheless, the power of those approaches is predicated on precise knowledge of the forms of the latitudinal gradient, the area relationship, and their interaction. We used a model developed by J. Pastor, A. Downing, and H. E. Erickson for assessing the effects of scale on the productivity–diversity gradient to avoid such complications. More specifically, for 253 sets …