Developmental Biology Commons^™

Effects Of Calcium Availability On The Reproductive Output Of Insectivorous Bats, Christina M. Booher

All-Inclusive List of Electronic Theses and Dissertations

Reproduction is a period of high calcium demand in vertebrates, and calcium deficiency can limit reproductive output in mammals. Insects are a poor calcium source, suggesting that insectivorous species are more likely to be calcium deficient. Pregnant big brown bats (Eptesicus fuscus) consume 10 times less calcium than they are estimated to require. To accommodate calcium demand during pregnancy, many mammals mobilize more calcium from the skeleton, and extensive bone loss has been observed in some bats during pregnancy. A conflict may arise between the female and developing embryo over allocation of limited calcium supplies, which could limit reproductive output …

Rapid Assimilation Of Yolk Enhances Growth And Development Of Lizard Embryos From A Cold Environment, Melissa Ann Blake

All-Inclusive List of Electronic Theses and Dissertations

Selection for rapid growth in cold environments results in a geographic pattern known as countergradient variation. The eastern fence lizard, Sceloporus undulatus, exhibits countergradient variation in growth rate across latitudinal clines. In a common-garden experiment, S. undulatus embryos from cold environments grew more efficiently than embryos warm environments, even when the energetic contents of eggs were equalized. To examine the physiological mechanisms of higher growth efficiency, I measured the energetics of embryos during the first 49 days of incubation. Specifically, I recorded body mass, residual yolk, total respiration, and developmental stage for embyos from two populations (Virginia and South Carolina). …

Phylogenetic Analyses Of Mtdna Sequences Reveal Three Cryptic Lineages In The Widespread Neotropical Frog Leptodactylus Fuscus (Schneider, 1799) (Anura, Leptodactylidae), Arley Camargo, Rafael O. De Sá, W. Ronald Heyer

Biology Faculty Publications

Leptodactylus fuscus is a neotropical frog ranging from Panamá to Argentina, to the east of the Andes mountains, and also inhabiting Margarita, Trinidad, and the Tobago islands. We performed phylogenetic analyses of 12S rRNA, 16S rRNA, tRNA-Leu, and ND1 mitochondrial (mt) DNA sequences from specimens collected across the geographic distribution of L. fuscus to examine two alternative hypotheses: (i) L. fuscus is a single, widely distributed species, or (ii) L. fuscus is a species complex. We tested statistically for geographic association and partitioning of genetic variation among mtDNA clades. The mtDNA data supported the hypothesis of several cryptic species within …

Comparing Immune Responses Of Juvenile And Adult Northern Fence Lizards, Sceloporus Undulatus, Zaïna Sandrine Kabange

All-Inclusive List of Electronic Theses and Dissertations

Sex steroid hormones affect behavior and morphological traits important in sexual selection. Steroid hormones also play a role in the development and functioning of immune system components. The immunocompetence handicap hypothesis (Folstad and Karter, 1992) proposes that tradeoffs, mediated by plasma levels of testosterone, exist between the immune system and elaboration of secondary sexual traits. Endocrine-immune interactions are well documented in birds and mammals, and steroid hormones can be immunoenhancing or immunosuppressive. Relatively little work has examined the ontogeny of immune function, and the interactions between steroid hormones and the immune system in reptiles. The first experiment addressed the question …

Morphological And Molecular Defects In Zebrafish Embryos (Danio Rerio) After Chromated Copper Arsenate Exposure, Kerry Jean Lee

Biological Sciences Theses & Dissertations

This investigation identified the morphological defects caused by different concentrations of chromium, copper, and arsenic (CCA) on the developing zebrafish embryo; in addition to defects caused by the three combined components (complete CCA). A change in the DNA of the developing embryos in response to the three components of CCA and complete CCA was also determined. Early Dania rerio embryos were cultured for five days with various concentrations of CCA components and complete CCA. Morphological defects were assessed with light microscopy and DNA fragmentation was determined by agarose gel electrophoresis. Embryonic exposure of D. rerio to sub lethal concentrations of …

Thermal Adaptation Of Maternal And Embryonic Phenotypes In A Wide Spread Lizard (Sceloporus Undulatus), Christopher E. Oufiero

All-Inclusive List of Electronic Theses and Dissertations

Geographically widespread ectotherms encounter thermal gradients that generate variation in behavior, physiology and life-history. Because rates of physiological processes are very sensitive to temperature, cold environments are thought to favor genotypes that have relatively high capacities for growth despite environmental constraints. Two different adaptive responses can occur: (1) mothers in colder environments can allocate more energy to each offspring, or (2) offspring in colder environments make more efficient use of available resources. In this study, I examined both maternal adaptations and embryonic adaptations to environmental temperature. Evidence of maternal adaptations was assessed by examining the relationship between egg size and …

Does Antarctic Krill Employ Body Shrinkage As An Overwintering Strategy?, Se-Jong Ju, H. Rodger Harvey, H. C. Shinn, Y. Kim, S. H. Kang

OES Faculty Publications

To determine if Antarctic krill employ body shrinkage as one of its overwintering mechanisms in the field, Euphausia superba and Euphausia crystallorophias were collected during fall and winter in and around Marguerite Bay through US Southern Ocean GLOBEC field programs during fall and winter 2001 and 2002. The relationships between the body length and weight of both krill species were exponentially correlated with no significant differences between the two species (p>0.05). The ratio between eye diameter and body length of individual krill was examined in an expectation that it could be used as an indicator of the body shrinkage …

Demographic Assessment Of The Blue Crab (Callinectes Sapidus) In Chesapeake Bay Using Extractable Lipofuscins As Age Markers, Se-Jong Ju, David H. Secor, H. Rodger Harvey

OES Faculty Publications

The blue crab (Callinectes sapidus) plays an important economic and ecological role in estuaries and coastal habitats from the Gulf of Mexico to the east coast of North America, but demographic assessments are limited by length-based methods. We applied an alternative aging method using biochemical measures of metabolic byproducts (lipofuscins) sequestered in the neural tissue of eyestalks to examine population age structure. From Chesapeake Bay, subsamples of animals collected from the 1998-99 (n-769) and 1999-2000 (n=367) winter dredge surveys were collected and lipofuscin was measured. Modal analysis of the lipofuscin index provided separation into three modes, whereas carapace-width …

The Tadpole Of Proceratophrys Avelinoi (Anura: Leptodactylidae), Rafael O. De Sá, José A. Langone

Biology Faculty Publications

The genus Proceratoprhys is poorly known. It consists of 14 currently recognized species (Frost, 2000) of medium-sized frogs distributed from northeastern Argentina and Paraguay to southeast Amazonia (Rondonia State), eastern and southern Brazil Proceratophrys avelinoi was described from Misiones, Argentina (Mercadal de Barrio and Barrio, 1993). The larval stage of this species is unknown. Herein, we describe the tadpole and the characteristics of the internal oral anatomy of P. avelinoi using scanning electron microscopy (SEM).

Factors Influencing Spatial Variability In Soil Nitrogen (N) Dynamics In N-Treated And Untreated Watersheds Of The Fernow Experimental Forest, West Virginia, Nikki Lenore Lyttle

Theses, Dissertations and Capstones

The central Appalachian region of the United States receives some of the highest inputs of nitrogen (N) due to acidic deposition in the nation. It is believed that these high could levels contribute to a decline in forest soils within the next 50 to 70 yrs. This study examines factors that influence spatial variability in N-treated and untreated watersheds of the Fernow Experimental Forest, Parsons, West Virginia. Within each of the two watersheds [WS4 untreated control, > 100 yr.; WS3 N-treated, acidified, clear cut, ~ 31 yr.], two 0.04 ha plots, one high N and one low N, were selected for …

Growth Rate Variability And Lipofuscin Accumulation Rates In The Blue Crab Callinectes Sapidus, Se-Jong Ju, David H. Secor, H. Rodger Harvey

OES Faculty Publications

To better understand growth and age-pigment (lipofuscin) accumulation rates of the blue crab Callinectes sapidus under natural conditions, juveniles (33 to 94 mm carapace width) were reared in outdoor ponds for over 1 yr. Growth rates, measured by carapace width, during summer and fall exceeded all those reported in the literature; the initial carapace width of 59 ± 14 mm (mean ± SD) increased to 164 ± 15 mm within a 3 mo period. No growth occurred during winter months (November to April) at low water temperatures. Growth rates of crabs in ponds were substantially higher (von Bertalanffy growth parameter …

Chondrocranium And Visceral Skeleton Of Atelopus Tricolor And Atelophryniscus Chrysophorus, E O. Lavilla, Rafael O. De Sá

Biology Faculty Publications

Atelopus tricolor and Atelophryniscus chrysophorus have gastromyzophorous tadpoles. Aside from specific differences, the larval chondrocrania and visceral skeletons show several shared character states, including an almost quadrangular, open chondrocranium , cornua trabeculae with expanded tips, cartilago suprarostralis as a single element, a posteriorly projected arcus subocularis quadrati, a closed muscular tunnel, and a simplified branchial basket, with only three pairs of ceratobranchiales. They are compared with diverse character states of suctorial larvae considering them as causally related to the stream life adaptations.

Do Timing And Pattern Of Myogenesis Correlate With Life History Mode In Anurans?, Matthew T. Smetanick, Rafael O. De Sá, Gary P. Radice

Biology Faculty Publications

The timing and pattern of myogenesis varies among anurans that have been studied and the different pat- terns may provide useful phylogenetic information. Specific myogenic markers have been described (Muntz, 1975; Kielbowna, 1981; Boudjelida & Muntz, 1987; Radice et al., 1989) and they can provide infor- mation on evolutionary changes for closely related lineages within a clade. For example, we previously com- pared first appearance of a muscle-specific protein, first twitch of axial muscle, onset of multinucleation within axial myotome, and first heartbeat in two pipid genera (Smetanick et al., 1999). We found that although the timing of myogenesis differed, …

The Life History Of The Cave Salamander, Eurycea Lucifuga Rafinesque, In West Virginia, Andrew James Longenecker

Theses, Dissertations and Capstones

In West Virginia, as throughout its range, there is limited information about the life history of the cave salamander (Eurycea lucifuga). The purpose of this study was to describe the natural history of this species in West Virginia. The objectives of this study were to determine habitat selection of the cave salamander, to ascertain its environmental characteristics, and to study its reproductive and non-reproductive biology. Three study caves were located in Greenbrier County, West Virginia. All sites were examined at least once each month from May 1999 through April 2000. Caves were divided into three zones: entrance, twilight, …

Ecology And Sympatric Relations Of Crevice Salamanders In Randolph County, West Virginia, Jayme Linn Waldron

Theses, Dissertations and Capstones

By implementing a mark-recapture study, I investigated the ecology of three species of sympatric plethodontid salamanders (Aneides aeneus, Desmognathus ochrophaeus, and Plethodon glutinosus) on rock outcrops in the Westvaco Wildlife and Ecosystem Research Forest, Randolph County, West Virginia. By examining activity patterns, vertical stratification, and habitat preference for A. aeneus, D. ochrophaeus, and P. glutinosus, I attempted to offer some insight into how these sympatric species avoid competition on small, isolated rock outcrops. Twenty-one surveys, both nocturnal and diurnal, were performed between 11 May and 17 October, 1999. During this time, 89 salamanders, encompassing five species ( …

Three-Dimensional Reconstructions Of Tadpole Chondrocrania From Histological Sections, Gary P. Radice, Mary Kate Boggiano, Mark Desantis, Peter M. Larson, Joseph Oppong, Matthew T. Smetanick, Todd M. Stevens, James Tripp, Rebecca A. Weber, Michael Kerckhove, Rafael O. De Sá

Biology Faculty Publications

Reconstructing three dimensional structures (3DR) from histological sections has always been difficult but is becoming more accessible with the assistance of digital imaging. We sought to assemble a low cost system using readily available hardware and software to generate 3DR for a study of tadpole chondrocrania. We found that a combination of RGB camera, stereomicroscope, and Apple Macintosh PowerPC computers running NIH Image, Object Image, Rotater. and SURFdriver software provided acceptable reconstructions. These are limited in quality primarily by the distortions arising from histological protocols rather than hardware or software.

Use Of Extractable Lipofuscin For Age Determination Of Blue Crab Callinectes Sapidus, Se-Jong Ju, David H. Secor, H. Rodger Harvey

OES Faculty Publications

The blue crab Callinectes sapidus is an economically and ecologically important species in many temperate estuaries, yet stock assessments have been limited to length-based methods for demographic analyses. We evaluated the potential of age pigments (lipofuscins) sequestered in neural tissue of eye-stalks and brains to estimate the age of blue crabs collected from Chesapeake Bay and Chincoteague Bay. The rate of lipofuscin accumulation was determined using crabs of known age reared in the laboratory. Age pigments were extracted from neural tissues (eye-stalk or brain), quantified, and normalized to protein content to allow comparisons across tissue types and crab sizes. Field-collected …

Estructura Del Condrocráneo Y Esqueleto Visceral De Larvas De Pseudis Minuta (Anura, Pseudidae, E. O. Lavilla, Rafael O. De Sá

Biology Faculty Publications

The chondrocranium and visceral skeleton of Pseudis minuta tadpoles are described, based on a series of five larvae in stages 31 - 35 of Gosner (1960). Among their striking characters are the presence of peculiar articular surfaces between cornua trabeculae and suprarostral cartilage, the incomplete development of the orbital cartilage, the high fenestration of the floor of the cavum cranii, the fusion of posterior foramina, and the fusion of spicules 3 and 4 in the hyobranchial skeleton.

Development Of The Suprarostral Plate Of Pipoid Frogs, Rafael O. De Sá, Charles C. Swart

Biology Faculty Publications

The rostral region of nonpipoid tadpoles has two sets of cartilages, the cornua trabeculae and the suprarostral cartilages, whereas the rostral region in pipoid larvae is occupied by a single and continuous cartilage, the suprarostral plate. The homology of this region in pipoid and nonpipoids tadpoles has been controversial. We examined the early formation and development of the suprarostral plate using serially cross-sectioned specimens of Rhinophrynus, Xenopus, and Hymenochirus. We conclude that the cartilaginous structures present in the rostral area of pipoid and nonpipoid larvae are homologous. Furthermore, we found two different developmental patterns among pipoid larvae. The chondrocranium …

The Biology Of Xenopus By R. C. Tinsley And H. C. Kobel, Rafael O. De Sá

Biology Faculty Publications

The Biology of Xenopus presents a summary of current knowledge about a single genus resulting from a symposium held at the Zoological Society of London in September 1992. This approach to summarizing available information has also been taken for other taxa, such as Atelopus (Lotters, 1996). However, the task of compiling data for Xenopus is enormous relative to any other amphibian group, because Xenopus laevis has become a model system for molecular and development research (Cannatella and de Sa, 1993). Unfortunately, most of our knowledge of Xenopus is biased toward this single species. There are about 20 recognized species of …

Chondrocranial Morphology Of Leptodactylus Larvae (Leptodactylidae: Leptodactylinae): Its Utility In Phylogenetic Reconstruction, Peter M. Larson, Rafael O. De Sá

Biology Faculty Publications

Chondrocranial morphology of leptodactylid frogs is scarcely known and has not been completely described for any species of Leptodactylus. We describe the diversity of chondrocranial morphology in the genus Leptodactylus based on the analysis of 22 species, representing the four species groups: the fuscus Group, ocellatus Group, melanonotus Group, and pentadactylus Group. Furthermore, 26 characters are identified and used in a phylogenetic analysis. The phylogenetic analysis using Physalaemus, Crossodactylus, and Hylodes as outgroups suggests two monophyletic clades within Leptodactylus: the melanonotus-ocellatus clade and the pentadactylusfuscus clade. However, it does not support the monophyly of the species groups as currently recognized …

The Tadpole Of Pseudis Minuta (Anura: Pseudidae), An Apparent Case Of Heterochrony, Rafael O. De Sá, Esteban O. Lavilla

Biology Faculty Publications

The external morphology, oral disc, and coloration pattern of the larva of Pseudis minuta are described. Tadpoles are mostly bottom dwellers that have a small, terminal oral disc with a labial tooth row formula 1(1-1)/(1-1)2. Internal oral anatomy is characterized using scanning electron microscopy, representing the only description available for the family Pseudidae. The coloration pattern of P. minuta tadpoles is compared with that of other pseudids. Pseudis minuta larvae do not exhibit the ontogenetic coloration change reported for P. paradoxa. Considering larval coloration, larval size, and reports of adult size, acceleration or hypermorphosis are suggested as possible heterochronic mechanisms …

External Morphology Of The Chorion Of The Annual Fishes Cynolebias (Cyprinodontiformes: Rivulidae), Marcelo Loureiro, Rafael O. De Sá

Biology Faculty Publications

Members of the family Rivulidae (killifishes) inhabit temporary bodies of freshwater in South and Central America (one species is also found in North America). The most remarkable characteristic of the family Rivulidae is that species have an annual life cycle with a drought-resistant egg during the dry season. Parenti's (1981) analysis of the order Cyprinodontiformes considered a single genus, Cynolebias, whereas Cos- ta's (1990) phylogenetic analysis of the family Rivulidae separates Cynolebias from Cynopoecilus. One of Costa's synapomorphies to separate Cynopoecilus is the unique structure of their egg's chorion, which is shared with Leptolebias and Campellolebias.

Development And Lipid Composition Of The Harpacticoid Copepod Nitocra Spinipes Reared On Different Diets, Gregory M. Weiss, George B. Mcmanus, H. Rodger Harvey

OES Faculty Publications

We reared the harpacticoid copepod Nitocra spinipes on diets of bacteria, a diatom, or a macroalga, evaluating survivorship and growth in short-term (≤ 1 generation) experiments. Lipid content of the copepods and their diets was measured and used as an index of nutrition. Although growth, survivorship and lipid content of N. spinipes were significantly greater when fed the diatom, which had the highest lipid content of the 3 diets, the copepod was able to develop from egg to adult when fed a lipid- poor bacterial diet. Furthermore, this species was able to go through developmental molts without the addition of …

Características De La Osificación Craneal En Phyllomedusa Boliviana (Anura: Hylidae), Rafael O. De Sá, E. O. Lavilla

Biology Faculty Publications

RESUMEN. Dentro de la familia Hylidae disponemos de información sobre las secuencias de osificación craneal para menos del 4.0% de sus miembros. El presente trabajo describe la secuencia de osificación craneal de Phyllomedusa boliviana. El patrón general de osificación es similar a lo reportado para otras especies de la familia, pero existen algunas diferencias importantes tales como la osificación tardía de los próoticos y la osificación premetamórfica de neopalatino, vómer, cuadrado-yugal, pterigoides y columela. El lento desarrollo ulterior de la osificación resulta en juveniles con cráneos extensamente cartilaginosos.

ABSTRACT. Characteristics of the cranial ossification in Phyllomedusa …

Trophic Transfer Of Fatty Acids, Sterols, And A Triterpenoid Alcohol Between Bacteria, A Ciliate, And The Copepod Acartia Tonsa, Melissa C. Ederington, George B. Mcmanus, H. Rodger Harvey

OES Faculty Publications

The incorporation of lipids into the copepod Acartia tonsa and its eggs was measured when it was fed either a bacterivorous ciliate (Pleuronema sp.) or a diatom (Thalassiosira weissflogii). Egg production was 10-fold higher on the diatom diet, whereas hatch success of eggs was the same for algal and ciliate diets. Adult copepods fed diatoms contained more total fatty acid and sterols than copepods fed the ciliate diet, and individual lipids reflected the dietary source. Eggs from diatom-fed copepods had fewer fatty acids but more sterols than eggs from copepods on a ciliate diet. Ciliate-fed copepods and …

Xenopus Laevis As A Model Organism, David C. Cannatella, Rafael O. De Sá

Biology Faculty Publications

Model organisms are often assumed to be representative of some more inclusive taxon of which the species is a part. This assumption leads to mistaken generalizations about the evolutionary and comparative significance of the data gathered. This paper reviews com? parative and evolutionary studies of Xenopus laevis and its relatives. Phylogenetic analysis of data from DNA sequences and morphology indicate that Xenopus is monophyletic and that Silurana is its sister group. The most basal lineages of Pipidae diverged prior to the breakup of Gondwana. The bizarre morphology of Xenopus is in part due to changes in the mode of meta? …

Karyology And Morphometrics Of Three Species Of Akodon (Mammalia: Muridae) From Northwestern Argentina, Rubén M. Barquez, Daniel F. Williams, Michael A. Mares, Hugh H. Genoways

University of Nebraska State Museum: Mammalogy Papers

Chromosomal and morphometric studies were conducted on a sample from an assemblage of Akodon spp. occurring in various patterns of sympatry from the provinces of Catamarca, Jujuy, Salta, and Tucumán, Argentina. Results showed three distinct morphometric groups based upon size. Size also varied with age, but there were no significant differences in measurements of males and females. The three morphometric groups have distinct karyotypes. Akodon caenosus Thomas is the smallest of the three, and has a karyotype of 2n = 34, FN = 40. A. boliviensis tucumanensis J. A. Allen is intermediate in size and has 2n = 40, FN …