No description available.

The gopher tortoise is a keystone species that creates networks of underground burrows that are home to an additional 350 species, where 60 are vertebrates. Vertebrates have been shown to differ between habitat types and seasonally, but limited information is known about vertebrate associates in our region. This study was one of the first to investigate this in our region of south Florida. This study was designed to investigate factors that may affect the presence of vertebrates at gopher tortoise burrows. Camera data was collected to determine vertebrate presence and if specific vertebrate groups elicit a territorial response from the tortoise, while habitat vegetation surveys and weather data were collected to evaluate seasonality. Statistical analysis showed variation in vertebrate presence both seasonally and by habitat type. Few territorial interactions were observed overall. This study acts as a starting point to increase our understanding of local tortoise populations. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2021. / FAU Electronic Theses and Dissertations Collection

We report an intertidal, bone-rich peat deposit on the windward (Atlantic Ocean) coast of Abaco, The Bahamas. The age of the Gilpin Point peat (c. 950-900 cal. yr BP) is based on five overlapping radiocarbon dates (one each from single pieces of wood of buttonwood Conocarpus erectus and sabal palm Sabal palmetto, and single bones of the Cuban crocodile Crocodylus rhombifer, Albury's tortoise Chelonoidis alburyorum, and green turtle Chelonia mydas). The short time interval represented by the charcoal-rich peat suggests rapid sedimentation following initial anthropogenic fires on Abaco. The site's diverse snail assemblage is dominated by terrestrial and freshwater species. The peat is exposed today only during exceptionally low tides, suggesting a lower sea level at the time of deposition as well as a degrading shoreline during the past millennium. Fossils from Gilpin Point represent a late-Holocene vertebrate community at the time of first human presence; only 10 of the 17 identified species of amphibians, reptiles, birds, and mammals still live on Abaco. Numerous unhealed bite marks on the inside of the thick carapaces of the green turtle attest to consumption by Cuban crocodiles, which probably scavenged turtles butchered by humans. This concept, along with the dense concentration of bones in the peat, and charring on some bones of the green turtle and Abaco tortoise, suggests a cultural origin of the bone deposit at Gilpin Point, where the only Amerindian artifact recovered thus far is a shell bead.

Nickel (Ni) is a metal that is anthropogenically enriched in aquatic settings. It has been reported as having three main modes of toxicity in freshwater animals (ionoregulatory disturbance, respiratory impairment, and the generation of oxidative damage), but there is little understanding of Ni toxicity in marine and estuarine environments. The mechanism(s) of Ni uptake and toxicity were investigated using three model species (adult green shore crab, Carcinus maenas; adult Atlantic killifish, Fundulus heteroclitus; early life-stages of the New Zealand sea urchin Evechinus chloroticus). In crabs, sea water protected against Ni accumulation and toxicity. In more dilute salinities, however, all three modes of Ni toxicity were identified at a sub-lethal level, with effects noted at Ni exposure levels as low as 8.2 µg/L, the US EPA environmental regulatory limit. In killifish, similar protective effects of SW were observed, however this species was much more resilient to Ni toxicity, with only minor changes in ionoregulation and oxidative stress noted, and no evidence of respiratory toxicity. Sea urchin larvae were found to be the most sensitive marine organisms to Ni toxicity yet reported, with a 96 h median effect concentration of 14.1 µg/L measured. Toxicity in this species was related to Ni impairment of calcium influx, consistent with proposed mechanisms of uptake observed in the other two models. Overall, the elevated ion levels associated with salinity were shown to be protective, suggesting a role for water chemistry in modifying Ni accumulation. However, physiology, which varies between species, developmental stages, and as a function of environmental salinity, also influenced organism sensitivity to Ni. These data contribute novel information regarding the relationships between water chemistry, Ni accumulation, and Ni toxicity, and as such, will be integral in the future development of predictive modelling tools for protecting marine and estuarine animals against environmental Ni. / Thesis / Doctor of Science (PhD)

No description available.

The hematological and rheological characteristics of blood from a number of vertebrates was compared to assess possible species differences in blood viscosity that may influence cardiovascular oxygen transport. Nucleated red blood cells (RBCs) were more viscous (measured by cone-plate viscometry) in comparison with enucleate (mammalian) RBCs at hematocrits greater than 40% when measured at equivalent temperatures. The lower viscosity of enucleate RBCs is attributed to an enhanced deformability of enucleate cells in comparison to nucleated cells.

"June 2003" Includes bibliographical references (leaves 408-457)

Collection of previously published articles / Includes Allozyme electrophoresis / B.J. Richardson, P.R. Baverstock and M. Adams (1986) / Includes bibliographies / 2 v. : / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (D. Sc.)--University of Adelaide, 1988

"June 2003" / Includes bibliographical references (leaves 408-457) / [26], 457 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Anatomical Sciences, 2003

All cellular processes depend on the coordinate expression of genes and their interactions. Regulatory sequences encoded in the genome stipulate the necessary instructions interpreted by sequence-specific transcription factors (TFs) to control the spatial-temporal output of gene expression. Detection of cis-regulatory signals is challenging, owing to the lack of distinguishing features such as open reading frames and an overwhelming excess of spurious to functional TF binding site matching sequences embedded within the vast non-coding regions of vertebrate genomes. From an evolutionary standpoint, functional alterations in cis-regulatory architecture are thought to be important in diversifying morphology and physiology in the evolution of vertebrates, which share a similar body plan and complement of genes. Correspondingly, recent studies have highlighted the plasticity of cis-regulatory architecture organization over evolutionary time, finding associations with examples of both diverged and conserved patterns of gene expression. These observations underscore the gap in our collective knowledge with respect to the rules by which TFs recognize and bind their targets in vivo, as well as how this process evolves in vertebrates, and serve as a motivating basis for this thesis work. To begin, I probed the extent of conservation and divergence of sequence and expression profiles across tissues of diverse vertebrate species, identifying thousands of candidate genes with conserved expression by microarray analysis. However, corresponding conservation of non-exonic and potentially regulatory sequence was lacking, suggestive of binding site turnover over evolutionary time. Next, I analyzed the sequence specificity of a wide array of mouse and yeast TFs, finding great diversity and complexity in their binding preferences, with many factors recognizing multiple distinct motifs. Furthermore, comparative analysis of orthologous TFs suggest well conserved binding specificities. I also demonstrate the likely biological relevance of sequences highly preferred by these TFs by revealing distinctive signatures in their distribution and organization within putative regulatory regions in each genome. Lastly, I have begun to explore the organization of cis-regulatory sequences active in vertebrate tissues by high-throughput sequencing of open chromatin. Together, these data help illuminate the organization and evolution of vertebrate regulatory architectures, providing a useful toolkit for the testing of new models and hypotheses.