Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 30 of 213

Full-Text Articles in Life Sciences

Age, Growth And Reproduction Of Western North Atlantic Butterfly Rays (Myliobatiformes: Gymnuridae), With The Description Of Two New Species, Kristene Teal Parsons Jan 2017

Age, Growth And Reproduction Of Western North Atlantic Butterfly Rays (Myliobatiformes: Gymnuridae), With The Description Of Two New Species, Kristene Teal Parsons

Dissertations, Theses, and Masters Projects

Batoid fishes are among the most threatened and least understood chondrichthyan species worldwide due to their large body size, conservative life-history characteristics, and predominantly coastal distributions where fishing and habitat degradation threaten the stability of populations. A lack of empirical life history data is widespread across batoid taxa — nearly half of all species are considered data deficient, thus hindering species assessments and the development of effective management strategies. Furthermore, many batoid taxa are in need of taxonomic re-examination. Increasing our understanding of life history traits that determine population productivity, such as age and size at maturity, growth rate, and fecundity ...


Reproductive Altruism, Social Diversity And Host Association In Sponge-Dwelling Snapping Shrimps, Synalpheus, Tin Chi Solomon Chak Jan 2016

Reproductive Altruism, Social Diversity And Host Association In Sponge-Dwelling Snapping Shrimps, Synalpheus, Tin Chi Solomon Chak

Dissertations, Theses, and Masters Projects

The diversity of animal social strategies has interested evolutionary biologists since the time of Darwin. Eusociality—the apex of animal sociality—traditionally characterized by cooperative offspring care, overlapping generations and reproductive division of labor, was until recently known only in insects and a few vertebrate species. The independent evolution of eusociality in shrimps in the genus Synalpheus offers a unique opportunity to test the generality of social evolution theories that are based mainly on insects and social vertebrates. The genus Synalpheus is particularly ideal for comparative analysis because their social organizations are highly diverse, yet they share very similar ecology ...


Phylogeny, Ontogeny And Distribution Of The Ribbonfishes (Lampridiformes: Trachipteridae), Jennifer M. Martin Jan 2015

Phylogeny, Ontogeny And Distribution Of The Ribbonfishes (Lampridiformes: Trachipteridae), Jennifer M. Martin

Dissertations, Theses, and Masters Projects

The ribbonfish family Trachipteridae (Lampridiformes) includes three well-defined genera (Trachipterus, Desmodema, and Zu), which are distributed worldwide throughout the pelagic marine environment as with most families of Lampridiformes, drastic changes in morphology occur throughout ontogeny due to extreme allometric growth. Combined with the rarity of specimens, this has led to the description of different life history stages as different species, rather than as part of the ontogenetic continuum of a single species. There is significant uncertainty concerning the ontogeny, distribution, nomenclature, number and phylogenetic affinity of trachipterid and other lampridiform genera.;The first chapter of my dissertation is a taxonomic ...


The Reproductive Biology Of Striped Bass (Morone Saxatilis) In Chesapeake Bay, Carissa L. Gervasi Jan 2015

The Reproductive Biology Of Striped Bass (Morone Saxatilis) In Chesapeake Bay, Carissa L. Gervasi

Dissertations, Theses, and Masters Projects

The Striped Bass (Morone saxatilis) is an anadromous finfish that supports a lucrative fishery along the Atlantic coast of the United States and serves as a vital component of estuarine food webs. Once Striped Bass stocks were restored after crashing in the late 1980s, abundance skyrocketed to record levels. Over the past decade however, abundance has steadily declined, concurrent with an outbreak of mycobacteriosis. Disease prevalence is currently >50%, and previous research has demonstrated diseasepositive fish exhibit slower growth and increased natural mortality compared to diseasenegative fish. The purpose of this research was to provide a contemporary description of Chesapeake ...


Habitat Use Of The Declining Wood Thrush In Coastal Virginia, Vitek Jirinec Jan 2015

Habitat Use Of The Declining Wood Thrush In Coastal Virginia, Vitek Jirinec

Dissertations, Theses, and Masters Projects

No abstract provided.


Effect Of Noise On The Social Structure Of European Starlings (Sturnus Vulgaris), Autumn Swan Jan 2015

Effect Of Noise On The Social Structure Of European Starlings (Sturnus Vulgaris), Autumn Swan

Dissertations, Theses, and Masters Projects

No abstract provided.


Phylogenetic Systematics Of The Prickleback Family Stichaeidae (Cottiformes: Zoarcoidei) Using Morphological Data, Todd R. Clardy Jan 2014

Phylogenetic Systematics Of The Prickleback Family Stichaeidae (Cottiformes: Zoarcoidei) Using Morphological Data, Todd R. Clardy

Dissertations, Theses, and Masters Projects

The prickleback family Stichaeidae, as currently recognized, is a diverse group of small (<30 cm TL) eel- or blenny-like marine fishes distributed in intertidal, subtidal, and continental slope waters of the North Pacific, Arctic, and North Atlantic oceans. Stichaeidae is one of nine families within the Cottiformes suborder Zoarcoidei and includes six subfamilies, 38 genera, and about 80 species. However, there are questions regarding the monophyly of the family and its position within Zoarcoidei, due in part to a lack of fundamental descriptive anatomical data for the family. The first chapter of my dissertation describes the osteology of Xiphister, a genus of Stichaeidae that includes two species, X. atropurpureus and X. mucosus, found in intertidal and subtidal waters from southern Alaska to southern California. I describe and illustrate their skeletal anatomy, clarify aspects of their anatomy discussed by previous researchers, and describe for the first time elements such as the hyoid and gill arches, scales, and the development of their lateral line canals. These data establish a foundation for the further anatomical and systematic studies of Stichaeidae, and Zoarcoidei generally. Some members of Stichaeidae, including both species of Xiphister , have multiple lateral line canals on their trunk, which is a feature found in only 15 families of teleostean fishes. In the second chapter of my dissertation, the structure and ontogeny of lateral line canals of both species of Xiphister were studied using cleared & stained specimens and histology. Both species have seven cephalic canals and three paired canals on the trunk located on the dorsolateral, mediolateral, and ventrolateral body surfaces. The ventrolateral canal also includes a short loop across the ventral surface of the abdomen. The trunk canals and four short branches of the infraorbitals that extend across the cheek are supported by small ossified rings. The trunk canals develop asynchronously and separately from the development of scales, suggesting that the ossified rings that support the canals are not modified scales. Results from histology show that neuromasts, the sensory components of the mechanosensory system, are found only in the cephalic, dorsolateral, and mediolateral canals; the ventrolateral canal and its loop lack neuromasts. The evolution and functional role of multiple trunk lateral line canals is discussed. The third chapter of my dissertation examines the phylogenetic systematics of Stichaeidae using 106 morphological characters and 60 terminal taxa, including 30 genera of Stichaeidae, representatives from all eight other families of Zoarcoidei, and additional outgroup taxa. The suborder Zoarcoidei was recovered as a monophyletic group sister to Cottoidei within the order Cottiformes. Within Zoarcoidei, however, the family Stichaeidae was not recovered as a monophyletic family. Only two of the six subfamilies within Stichaeidae, Lumpeninae and Neozoarcinae, were recovered as monophyletic. The high level of homoplasy in the remaining four stichaeid subfamilies, and the inclusion of zoarcoid families nested within Stichaeidae, suggests that the current classification of Stichaeidae does not accurately reflect the evolutionary history of Zoarcoidei.


Rise Of A Floater Class: Behavioral Adjustments By Breeding Bald Eagles In A Population Approaching Saturation, Courtney L. Turrin Jan 2014

Rise Of A Floater Class: Behavioral Adjustments By Breeding Bald Eagles In A Population Approaching Saturation, Courtney L. Turrin

Dissertations, Theses, and Masters Projects

No abstract provided.


Natural Variation In Fertility And Gnrh Neurons In A Wild, Natural Population Of White-Footed Mice, Peromyscus Leucopus, Melissa Proffitt Jan 2014

Natural Variation In Fertility And Gnrh Neurons In A Wild, Natural Population Of White-Footed Mice, Peromyscus Leucopus, Melissa Proffitt

Dissertations, Theses, and Masters Projects

No abstract provided.


Patterns Of Population Structure And Historical Dispersal In Squaloid Sharks: A Species-Level Approach Using Molecular Markers, Ana Christina Pimenta Verissimo Jan 2012

Patterns Of Population Structure And Historical Dispersal In Squaloid Sharks: A Species-Level Approach Using Molecular Markers, Ana Christina Pimenta Verissimo

Dissertations, Theses, and Masters Projects

Squaloids (Order Squaliformes) are a highle diverse group of mostly deepwater habitats (> 200 m). Many species are regularly caught in commercial fisheries worldwide but their low productivity and correspondingly low intrinsic rebound potentials make them particularly vulnerable to population depletion and overexploitation. of special concern to fisheries management and conservation efforts are the spiny dogfish Squalus acanthias, the leafscale gulper shark Centrophorus squamosus and the Portuguese dogfish Centroscymnus coelolepis. These taxa have recently been declared overfished in several parts of each species' distribution but management efforts have been made to recover the "stocks" without a good understanding of the species ...


Sexual Dimorphism, Diet, And Body Condition Of Rusty Blackbirds Wintering In Virginia, Andrew John Mcgann Jan 2012

Sexual Dimorphism, Diet, And Body Condition Of Rusty Blackbirds Wintering In Virginia, Andrew John Mcgann

Dissertations, Theses, and Masters Projects

No abstract provided.


Behavioral And Mechanical Particle Selectivity In A Suspension-Feeding Detritivorous Fish, Matthew Kyle Heidman Jan 2011

Behavioral And Mechanical Particle Selectivity In A Suspension-Feeding Detritivorous Fish, Matthew Kyle Heidman

Dissertations, Theses, and Masters Projects

No abstract provided.


Mate-Guarding In The Australian Zebra Finch, Taeniopygia Guttata: For Males, Protecting Paternity Is More Important Than Extra-Pair Copulations, Leah Catherine Wilson Jan 2011

Mate-Guarding In The Australian Zebra Finch, Taeniopygia Guttata: For Males, Protecting Paternity Is More Important Than Extra-Pair Copulations, Leah Catherine Wilson

Dissertations, Theses, and Masters Projects

No abstract provided.


The Influence Of Golf Course Landscapes On The Occupancy And Reproductive Success Of Eastern Bluebirds, Marie Louise Pitts Jan 2011

The Influence Of Golf Course Landscapes On The Occupancy And Reproductive Success Of Eastern Bluebirds, Marie Louise Pitts

Dissertations, Theses, and Masters Projects

No abstract provided.


Migration Dynamics, Within-Estuary Behaviors And Cardiorespiratory Responses Of Summer Flounder To Selected Estuarine Conditions, Karen M. Capossela Jan 2010

Migration Dynamics, Within-Estuary Behaviors And Cardiorespiratory Responses Of Summer Flounder To Selected Estuarine Conditions, Karen M. Capossela

Dissertations, Theses, and Masters Projects

A comprehensive understanding of migration dynamics, within-estuary behaviors and physiological tolerances of fish is needed to assess and predict future responses of fish to environmental disturbance and to protect habitat necessary for growth and survival. This study adds to current knowledge of summer flounder (Paralichthys dentatus) responses to environmental conditions by (1) examining migration and within-estuarine behaviors of adult summer flounder and (2) establishing summer flounder metabolic requirements and cardiorespiratory responses to variations in hypoxia and temperature. To elucidate use of a southern mid-Atlantic Bight estuary by adult summer flounder, the movements of 45 fish were monitored using acoustic telemetry ...


Survival In An Urbanized Landscape: Radio-Tracking Fledgling Eastern Bluebirds (Sialia Sialis) On Golf Courses, Allyson Kathleen Jackson Jan 2010

Survival In An Urbanized Landscape: Radio-Tracking Fledgling Eastern Bluebirds (Sialia Sialis) On Golf Courses, Allyson Kathleen Jackson

Dissertations, Theses, and Masters Projects

No abstract provided.


Prey Utilization And Energy Demand Of A Breeding Peregrine Falcon (Falco Peregrinus) Population, Elizabeth Claire Long Jan 2009

Prey Utilization And Energy Demand Of A Breeding Peregrine Falcon (Falco Peregrinus) Population, Elizabeth Claire Long

Dissertations, Theses, and Masters Projects

No abstract provided.


Previous Experience Shapes Mate Preferences Of Female Zebra Finches (Taeniopygia Guttata), Kelly Caroline Minton Jan 2009

Previous Experience Shapes Mate Preferences Of Female Zebra Finches (Taeniopygia Guttata), Kelly Caroline Minton

Dissertations, Theses, and Masters Projects

No abstract provided.


Mud And Mucus: Feeding Selectivity In A Suspension-Feeding Detritivorous Fish, Marie Louise Lammons Jan 2009

Mud And Mucus: Feeding Selectivity In A Suspension-Feeding Detritivorous Fish, Marie Louise Lammons

Dissertations, Theses, and Masters Projects

No abstract provided.


Female Plumage Coloration In Eastern Bluebirds, Sialia Sialis: Is It A Sexually Selected Trait?, Joanna Kay Hubbard Jan 2009

Female Plumage Coloration In Eastern Bluebirds, Sialia Sialis: Is It A Sexually Selected Trait?, Joanna Kay Hubbard

Dissertations, Theses, and Masters Projects

No abstract provided.


Mercury Levels In Newly Independent Songbirds, Anne Moire Condon Jan 2008

Mercury Levels In Newly Independent Songbirds, Anne Moire Condon

Dissertations, Theses, and Masters Projects

No abstract provided.


Interactions Between Feather-Degrading Bacteria And Feather Coloration, Alexander Rahn Gunderson Jan 2008

Interactions Between Feather-Degrading Bacteria And Feather Coloration, Alexander Rahn Gunderson

Dissertations, Theses, and Masters Projects

No abstract provided.


Monograph Of The North American Freshwater Fish Leeches (Oligochaeta: Hirudinida ; Piscicolidae) And Molecular Phylogeny Of The Family Piscicolidae, Julianne I. Williams Jan 2007

Monograph Of The North American Freshwater Fish Leeches (Oligochaeta: Hirudinida ; Piscicolidae) And Molecular Phylogeny Of The Family Piscicolidae, Julianne I. Williams

Dissertations, Theses, and Masters Projects

The phylogeny of the Piscicolidae was analyzed from combined sequence data of 18S rDNA, cytochrome c oxidase subunit I (CO-I), nicotinamide adenine dinucleotide dehydrogenase subunit I (ND-I), and morphological data using parsimony. A worldwide distribution of Pisciolidae was represented for the first time in a phylogenetic analysis. While the family Piscicolidae was supported as a monophyletic group, the traditional subfamilies based on morphology were not supported. The Platybdellinae was polyphyletic and formed four distinct clades, and Bathybdella sawyeri did not group with any other platybdellids. The Piscicolinae was also polyphyletic, also forming four distinct clades. The pontobdellid genus Stibarobdella was ...


Repeatability Of Mate Preferences And Mate-Choice Copying In Female Zebra Finches, Amanda Karen Houck Jan 2007

Repeatability Of Mate Preferences And Mate-Choice Copying In Female Zebra Finches, Amanda Karen Houck

Dissertations, Theses, and Masters Projects

No abstract provided.


Development Of Generalized Index-Removal Models, With Particular Attention To Catchability Issues, Thomas F. Ihde Jan 2006

Development Of Generalized Index-Removal Models, With Particular Attention To Catchability Issues, Thomas F. Ihde

Dissertations, Theses, and Masters Projects

The index-removal method estimates abundance, exploitation and catchability coefficient, given surveys conducted before and after a known removal. The method assumes a closed population between surveys. Index-removal has seldom been applied due to its strong assumption of constant survey catchabilities. This work generalizes the method to allow multiple years of data to be incorporated, and the assumptions of the original model to be relaxed. If catchability is constant across years, precision can be improved by analyzing multi-year data simultaneously. Two multiple-year models were developed: the first, 1qIR, assumes constant catchability within and among years; the second, 2qIR, allows catchability to ...


Ecology And Conservation Of Virginia Shark Species: Analysis Of Thirty Years Of Virginia Long-Line Shark Census Data, 1974--2004, Daniel Stuart Ha Jan 2006

Ecology And Conservation Of Virginia Shark Species: Analysis Of Thirty Years Of Virginia Long-Line Shark Census Data, 1974--2004, Daniel Stuart Ha

Dissertations, Theses, and Masters Projects

Sharks of the Atlantic coast of the United States have suffered increased fishing pressure in last three decades. Commercial and recreational catches jumped in the mid to late 1980's, leading to regulation by the National Marine Fisheries Service in the early 1990's. The Virginia Institute of Marine Sciences' shark long-line survey, begun in 1974, and continuing to the present day, is thus well positioned to look at the effects of this fishing mortality on sharks. Using GAM modelling, six of ten shark species analyzed, including the most common species, Carcharhinus plumbeus, suffered declines of from 98-99% of early ...


Migratory And Spawning Behavior Of American Shad In The James River, Virginia, Aaron W. Aunins Jan 2006

Migratory And Spawning Behavior Of American Shad In The James River, Virginia, Aaron W. Aunins

Dissertations, Theses, and Masters Projects

No abstract provided.


Sources Of Mortality, Movements And Behavior Of Sea Turtles In Virginia, Katherine Lamont. Mansfield Jan 2006

Sources Of Mortality, Movements And Behavior Of Sea Turtles In Virginia, Katherine Lamont. Mansfield

Dissertations, Theses, and Masters Projects

Aerial surveys are commonly used to evaluate in-water sea turtle abundances. A correction is applied to account for turtles diving below the observed surface. Historically, observations of summer/fall surfacing behavior were used for this correction, assuming constant behavior among seasons. Using radio/acoustic telemetry, seasonal differences in sea turtle surfacing behavior were determined among Kemp's ridleys and loggerheads. Mean time spent at surface in the spring ranged between 9.9%-30.0% with significant differences among individuals. Observed surfacing times were higher than historic summer/fall observations (Byles 1988; 5.3%), indicating that historic springtime abundances were overestimated ...


Habitat Utilization And Salinity Tolerance Of The Sandbar Shark, Carcharhinus Plumbeus, In Virginia, Leonard Pace Jan 2006

Habitat Utilization And Salinity Tolerance Of The Sandbar Shark, Carcharhinus Plumbeus, In Virginia, Leonard Pace

Dissertations, Theses, and Masters Projects

No abstract provided.


Nursery Delineation, Movement Patterns, And Migration Of The Sandbar Shark, Carcharhinus Plumbeus, In The Eastern Shore Of Virginia Coastal Bays And Lagoons, Christina L. Conrath Jan 2005

Nursery Delineation, Movement Patterns, And Migration Of The Sandbar Shark, Carcharhinus Plumbeus, In The Eastern Shore Of Virginia Coastal Bays And Lagoons, Christina L. Conrath

Dissertations, Theses, and Masters Projects

The identification and delineation of nursery areas and areas of aggregation of north Atlantic sharks has been identified as an important information need for future management efforts. The objectives of this project were to use a fishery-independent method to study the overwintering area of juvenile sandbar sharks, to spatially delineate the Eastern Shore nursery area, and to examine movement patterns and space use within this nursery area. Data from 21 satellite transmitters attached to large juvenile sandbar sharks revealed that these sharks primarily occurred off the outer banks of North Carolina, at deeper depths and colder water temperatures during the ...