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comparison of stability in swimming loggerhead (Caretta caretta) and green (Chelonia mydas) sea turtle posthatchlings
Title
A comparison of stability in swimming loggerhead (Caretta caretta) and green (Chelonia mydas) sea turtle posthatchlings.
Creator
Dougherty, Erin., Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description
Posthatchling green (Chelonia mydas) and loggerhead (Caretta caretta) turtles overlap ecologically but differ morphologically. This study compared hydrodynamic stability between the two species during swimming to test for functional differences in body shape. Flipper movement paths, four stability measures (yaw, pitch, heave, and sideslip), and the relative positions of the centers of buoyancy and gravity were compared between species. Both centers of buoyancy and gravity lie in the anterior...
Show morePosthatchling green (Chelonia mydas) and loggerhead (Caretta caretta) turtles overlap ecologically but differ morphologically. This study compared hydrodynamic stability between the two species during swimming to test for functional differences in body shape. Flipper movement paths, four stability measures (yaw, pitch, heave, and sideslip), and the relative positions of the centers of buoyancy and gravity were compared between species. Both centers of buoyancy and gravity lie in the anterior body; their positions relative to one another differed with species, but showed no functional consequences. Neither species demonstrated substantial yaw, sideslip, or pitch. Both experienced upward heave with the flippers' downstroke and downward heave with the upstroke; however phase relationships differed between these limb and body motions. No differences were found between the two species. Despite obvious morphological differences, loggerheads and green turtles were similarly stable during swimming, suggesting that the species use different mechanisms to achieve stability.
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Date Issued
2009
PURL
http://purl.flvc.org/FAU/186689
Subject Headings
Sea turtles, Morphology, Sea turtles, Physiology, Animal locomotion, Marine ecology
Format
Document (PDF)
effects of anoxia on protein synthesis and transport in the optic system of the freshwater turtle, Trachemys scripta elegans
Title
The effects of anoxia on protein synthesis and transport in the optic system of the freshwater turtle, Trachemys scripta elegans.
Creator
McFadden, Kris Joseph, Florida Atlantic University, Lutz, Peter L.
Abstract/Description
The effects of anoxia on retinal protein synthesis and axonal transport were investigated in the freshwater turtle, Trachemys scripta. The optic system (retina, optic nerve, optic tract, and optic tectum) of the freshwater turtle was used because, due to its linear structure, it is an ideal model to measure protein production and transport. This species of turtle is known for its ability to withstand long periods of anoxia; however, little data is available on in vivo protein synthesis in the...
Show moreThe effects of anoxia on retinal protein synthesis and axonal transport were investigated in the freshwater turtle, Trachemys scripta. The optic system (retina, optic nerve, optic tract, and optic tectum) of the freshwater turtle was used because, due to its linear structure, it is an ideal model to measure protein production and transport. This species of turtle is known for its ability to withstand long periods of anoxia; however, little data is available on in vivo protein synthesis in the brain on an anoxia-tolerant species. An intraocular injection of S-methionine was used to label retinal proteins during 18 hours of anoxia, and the tissues were removed and prepared for analysis using 2D gel electrophoresis. Using autoradiography the regulation of retinal proteins was compared under normoxic and anoxic conditions. In addition, labeled retinal proteins rapidly transported along the optic nerve and tract, to the tectum were also compared under these conditions. Although certain proteins were produced in lesser amounts during anoxia, the populations of proteins were the same during anoxia as they were in the control, suggesting that all proteins were still produced during anoxia. Additionally, certain proteins were produced in greater amounts during anoxia. The findings suggest that less important proteins are down-regulated in response to anoxia while those proteins that are up-regulated may serve as protective mechanisms that enable the organism to maintain neuronal connections in this system during anoxia.
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Date Issued
1997
PURL
http://purl.flvc.org/fcla/dt/15509
Subject Headings
Turtles--Physiology, Anoxemia, Red-eared slider--Physiology
Format
Document (PDF)
Impact of the red imported fire ant (Solenopsis invicta ) on two species of sea turtle hatchlings
Title
Impact of the red imported fire ant (Solenopsis invicta ) on two species of sea turtle hatchlings.
Creator
Krahe, Holly B., Florida Atlantic University, Wetterer, James K.
Abstract/Description
Although the red imported fire ant (Solenopsis invicta ) is known to kill sea turtle hatchlings, little research has focused on sub-lethal effects of ant attacks on hatchlings emerging from nests. Sea turtle hatchlings of two species (Caretta caretta and Chelonia mydas) exposed to fire ants during incubation and emergence were collected on Juno Beach, Florida. Hatchlings were maintained for ten days in a common saltwater outdoor pool at the Marinelife Center, Juno Beach. Hatchlings showing...
Show moreAlthough the red imported fire ant (Solenopsis invicta ) is known to kill sea turtle hatchlings, little research has focused on sub-lethal effects of ant attacks on hatchlings emerging from nests. Sea turtle hatchlings of two species (Caretta caretta and Chelonia mydas) exposed to fire ants during incubation and emergence were collected on Juno Beach, Florida. Hatchlings were maintained for ten days in a common saltwater outdoor pool at the Marinelife Center, Juno Beach. Hatchlings showing pustules diagnostic of S. invicta stings were compared to non-stung controls in terms of survival, growth (mass and SCL) and initial crawling strength. Loggerhead hatchlings showed a significant decrease in survival, growth, and crawling strength when stung by fire ants. In contrast, no significant differences were seen in the survival, growth, and crawling strength of green turtle hatchlings when stung by fire ants.
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Date Issued
2005
PURL
http://purl.flvc.org/fcla/dt/13252
Subject Headings
Fire ants--Venom--Physiological effect, Loggerhead turtle--Mortality, Green turtle--Mortality, Sea turtles--Florida
Format
Document (PDF)
Brevetoxin Metabolism and Physiology - A Freshwater Model of Morbidity in Endangered Sea Turtles
Title
Brevetoxin Metabolism and Physiology - A Freshwater Model of Morbidity in Endangered Sea Turtles.
Creator
Cocilova, Courtney Christine, Milton, Sarah L., Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description
The dinoflagellate Karenia brevis is one organism responsible for harmful algal blooms (HABs) that severely impact marine life. K. brevis produces a suite of neurotoxins referred to as brevetoxins (PbTx) which bind to voltage-gated sodium channels (VGSCs) in excitable tissues, affecting cellular permeability leading to a suite of symptoms and potentially cell death. Brevetoxicosis is difficult to treat in sea turtles as the physiological impacts have not been investigated and the magnitude...
Show moreThe dinoflagellate Karenia brevis is one organism responsible for harmful algal blooms (HABs) that severely impact marine life. K. brevis produces a suite of neurotoxins referred to as brevetoxins (PbTx) which bind to voltage-gated sodium channels (VGSCs) in excitable tissues, affecting cellular permeability leading to a suite of symptoms and potentially cell death. Brevetoxicosis is difficult to treat in sea turtles as the physiological impacts have not been investigated and the magnitude and duration of brevetoxin exposure are generally unknown. Due to their threatened and endangered status, experimental exposures cannot be performed to determine the fate of brevetoxin in sea turtle tissues, making it difficult to design appropriate treatments. The freshwater turtle, Trachemys scripta, was utilized as a model for brevetoxin exposure in turtles. Turtles were exposed to intratracheal instillation (10.53μg/kg) or oral dosing (33.48μg/kg) of PbTx-3 3x weekly over a period of 2-4 weeks. Tissues and fluids were collected for ELISA to determine PbTx-3 uptake and distribution, routes of excretion and rates of clearance (1h-1wk post-exposure). Tissues were also preserved for histopathology. Primary turtle neuronal cell cultures were exposed to PbTx-3 in the presence and absence of various agonists and antagonists to determine brevetoxin’s mode of action. PbTx-3 was widely distributed in all tissues and fluids following both intratracheal and oral exposures, but was largely cleared from the system within 24 hours; PbTx-3 moved into the bile and feces over 48h post exposure indicating that this is the main route of excretion. While exposed animals showed clear behavioral symptoms of toxicity including muscle twitching, swimming in circles, and ataxia, there was no evident tissue pathology. Despite the evident behavioral effects, turtle neurons are surprisingly resistant to PbTx-3, with an EC50 significantly higher than is seen in mammalian neurons. While PbTx-3 exposure resulted in significant Ca2+ influx, various antagonists prevented Ca2+ influx when added with PbTx-3 confirming the mechanism of action through VGSCs. Upregulation of Hsp72 in the turtle brain could be enhancing cell survival. Based on results, intralipid treatment post PbTx-3 exposure rapidly decreases symptoms and proves to be a suitable treatment for toxin exposure.
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Date Issued
2017
PURL
http://purl.flvc.org/fau/fd/FA00004812
Subject Headings
Sea turtles--Mortality., Sea turtles--Physiology., Marine toxins., Neurotoxic agents--Analysis.
Format
Document (PDF)
Investigating maternal health and hatchling mortality in leatherback sea turtles (Dermochelys coriacea v.)
Title
Investigating maternal health and hatchling mortality in leatherback sea turtles (Dermochelys coriacea v.).
Creator
Perrault, Justin R., Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description
The reproductive success of leatherback turtles (Dermochelys coriacea) is typically the lowest of the seven sea turtle species. Why this vital rate is decreased has remained unanswered for nearly a century. Recently, detailed postmortem examination of leatherback hatchlings identified muscular pathologies that suggested possible selenium deficiency. High bodily burdens of mercury compounds are associated with selenium depletion. Selenium is a necessary detoxifying nutrient that itself can be...
Show moreThe reproductive success of leatherback turtles (Dermochelys coriacea) is typically the lowest of the seven sea turtle species. Why this vital rate is decreased has remained unanswered for nearly a century. Recently, detailed postmortem examination of leatherback hatchlings identified muscular pathologies that suggested possible selenium deficiency. High bodily burdens of mercury compounds are associated with selenium depletion. Selenium is a necessary detoxifying nutrient that itself can be toxic at elevated concentrations. Mercury compounds are toxicants with no known biological function. High bodily concentrations of mercury can be detrimental to marine organismal health, reproduction and survival, both directly and indirectly through inducing selenium depletion. The goals of this dissertation are to evaluate several related hypotheses to explain low leatherback nest success. ... Because leatherbacks take in high volumes of prey, high tissue concentrations of mercury and selenium can result. This study provides the first evidence that chemical contaminants may explain low reproductive success in leatherback sea turtles.
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Date Issued
2013
PURL
http://purl.flvc.org/fcla/dt/3362575
Subject Headings
Selenium, Physiological effect, Predation (Biology), Leatherback turtle, Mortality, Sea turtles, Mortality, Wildlife conservation
Format
Document (PDF)
Developmental Morphology of Flippers in Sea Turtles and Penguins
Title
Developmental Morphology of Flippers in Sea Turtles and Penguins.
Creator
Kwong, Grace W., Wyneken, Jeanette, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description
There are no modem anatomical studies of flipper development or particularly any examining limb formation across distantly related taxa converging on similar flipper morphology. This study compares and contrasts the development of flippers in sea turtle (Caretta caretta) and penguin (Spheniscus demersus , Eudyptula minor) embryos. Embryos were fixed, cleared and stained for cartilage anlagen, and prepared as whole mounts. Skeletal elements forming the flipper and changes in their growth rates...
Show moreThere are no modem anatomical studies of flipper development or particularly any examining limb formation across distantly related taxa converging on similar flipper morphology. This study compares and contrasts the development of flippers in sea turtle (Caretta caretta) and penguin (Spheniscus demersus , Eudyptula minor) embryos. Embryos were fixed, cleared and stained for cartilage anlagen, and prepared as whole mounts. Skeletal elements forming the flipper and changes in their growth rates were described across developmental stages. Results suggest skeletal elements contribute differently to sea turtle and penguin flipper blades and there are significant differences in bone shape and growth patterns. Greater proportional increases in lengths and areas were found in sea turtles elements compared to penguins. Sea turtles appear to depend on a pathway resulting in elongation of distal elements to build a flipper, whereas penguin limbs undergo flattening and expansion of fewer elements to meet a similar structural goal.
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Date Issued
2006
PURL
http://purl.flvc.org/fau/fd/FA00000784
Subject Headings
Sea turtles--Physiology, Sea turtles--Morphology, Penguins--Morphology, Animal locomotion, Marine ecology
Format
Document (PDF)
Specific dynamic action in hatchling and post-hatchling green (Chelonia mydas) and loggerhead (Caretta caretta ) sea turtles
Title
Specific dynamic action in hatchling and post-hatchling green (Chelonia mydas) and loggerhead (Caretta caretta ) sea turtles.
Creator
Kowalski, Amy, Florida Atlantic University, Milton, Sarah L., Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description
Specific dynamic action (SDA) describes a post-feeding increase in oxygen consumption where most energy derived from food is allocated to post-absorptive processes, including growth and maintenance. SDA and growth in hatchling sea turtles is of special interest because they experience drastic changes in diet, oxygen availability and habitat during the first several months of life. This study investigated SDA variation between species and among age groups. SDA was quantified in two species of...
Show moreSpecific dynamic action (SDA) describes a post-feeding increase in oxygen consumption where most energy derived from food is allocated to post-absorptive processes, including growth and maintenance. SDA and growth in hatchling sea turtles is of special interest because they experience drastic changes in diet, oxygen availability and habitat during the first several months of life. This study investigated SDA variation between species and among age groups. SDA was quantified in two species of sea turtle (Chelonia mydas, Caretta caretta) at 7, 30, 60, & 90 days post-hatching. Turtles were fed a known amount of food, and oxygen consumption was monitored using a metabolic chamber. SDA percentage of total energy did not increase with age (species pooled), although magnitude of SDA was higher in C. mydas when compared to C. caretta (ages pooled). These results imply that SDA does not increase proportionally with age, and that hatchling C. mydas use more absolute energy for SDA than C. caretta .
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Date Issued
2005
PURL
http://purl.flvc.org/fcla/dt/13283
Subject Headings
Adaptation (Biology), Sea turtles--Feeding and feeds, Physiology, Comparative, Sea turtles--Ecology
Format
Document (PDF)
Stress protein expression and green turtle fibropapillomatosis
Title
Stress protein expression and green turtle fibropapillomatosis.
Creator
McGarrity, Monica E., Florida Atlantic University, Milton, Sarah L.
Abstract/Description
Green turtle fibropapillomatosis (GTFP) is a highly debilitating disease that affects several species of marine turtles worldwide. This study evaluated stress protein expression in red blood cells (RBCs), skin and tumors of green turtles (Chelonia mydas) from a GTFP-prevalent site and a more pristine, GTFP-free site. Levels of expression of HSP72 were significantly higher in healthy turtles from the GTFP-prevalent site compared to healthy turtles from the GTFP-free site, suggesting that these...
Show moreGreen turtle fibropapillomatosis (GTFP) is a highly debilitating disease that affects several species of marine turtles worldwide. This study evaluated stress protein expression in red blood cells (RBCs), skin and tumors of green turtles (Chelonia mydas) from a GTFP-prevalent site and a more pristine, GTFP-free site. Levels of expression of HSP72 were significantly higher in healthy turtles from the GTFP-prevalent site compared to healthy turtles from the GTFP-free site, suggesting that these turtles are, indeed stressed. Levels of HSP72 expression were also significantly higher in the nucleated RBCs than in skin tissues of turtles from both sites. These results demonstrate the utility of RBC stress protein evaluation as a new, minimally invasive method of evaluating stress loads in marine turtles as a factor in the potentially multifactorial etiology of GTFP. In addition, HSP72 and GP96 were present and detectable in tumors of diseased turtles, and thus show potential for use in treatment of GTFP.
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Date Issued
2005
PURL
http://purl.flvc.org/fcla/dt/13269
Subject Headings
Green turtle--Diseases, Green turtle--Immunology, Stress (Physiology), Environmental monitoring
Format
Document (PDF)
Stress Protein and Anti-Apoptotic Protein Expression in Green Turtle (Chelonia mydas) Fibropapillomatosis
Title
Stress Protein and Anti-Apoptotic Protein Expression in Green Turtle (Chelonia mydas) Fibropapillomatosis.
Creator
Deming, Alissa C., Milton, Sarah L., Florida Atlantic University
Abstract/Description
Fibropapillomatosis (FP) is a devastating pandemic characterized by benign cutaneous neoplasias that is afflicting marine turtles worldwide. This study evaluated the expression of HSP72, GRP96, and Bcl-2 in tumor and healthy biopsies. These proteins are found in high levels in some tumors and prevent apoptosis, allowing tumor cells to survive. HSP72 and GRP96 are also known to initiate an immune response and may contribute to the regression often observed in FP tumors. Results were found that...
Show moreFibropapillomatosis (FP) is a devastating pandemic characterized by benign cutaneous neoplasias that is afflicting marine turtles worldwide. This study evaluated the expression of HSP72, GRP96, and Bcl-2 in tumor and healthy biopsies. These proteins are found in high levels in some tumors and prevent apoptosis, allowing tumor cells to survive. HSP72 and GRP96 are also known to initiate an immune response and may contribute to the regression often observed in FP tumors. Results were found that showed all three protective proteins had significantly higher levels in actively growing tumor tissue compared to healthy tissue. Specifically, cauliflower-like tumors, thought to be actively growing, were found to have higher levels of HSP72 and GRP96 compared to healthy skin, whereas smooth tumors, thought to be regressing, did not. These results offer insight into the molecular mechanisms behind the development of FP tumors and open a number of avenues for future research.
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Date Issued
2008
PURL
http://purl.flvc.org/fau/fd/FA00000740
Subject Headings
Stress (Physiology), Green turtle--Diseases, Environmental monitoring, Green turtle--Immunology
Format
Document (PDF)
Molecular mechanisms of neuroprotection in the anoxia tolerant freshwater turtle
Title
Molecular mechanisms of neuroprotection in the anoxia tolerant freshwater turtle.
Creator
Kesaraju, Shailaja., Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description
Cardiac ischemia, stroke and some neurodegenerative disorders are all characterized by cell damage and death due to low oxygen levels. Comparative studies show that anoxia tolerant model systems present a unique opportunity to study "survival" instead of death in the complete absence of oxygen. The freshwater turtle (Trachemys scripta elegans) is unique in its ability to survive total oxygen deprivation for hours to days, as well as reoxygenation insult after anoxia. The broad objective of...
Show moreCardiac ischemia, stroke and some neurodegenerative disorders are all characterized by cell damage and death due to low oxygen levels. Comparative studies show that anoxia tolerant model systems present a unique opportunity to study "survival" instead of death in the complete absence of oxygen. The freshwater turtle (Trachemys scripta elegans) is unique in its ability to survive total oxygen deprivation for hours to days, as well as reoxygenation insult after anoxia. The broad objective of this study is to understand the modulation of key molecular mechanisms involving stress proteins and VEGF that offer neuroprotection and enhance cell survival in the freshwater turtle through anoxia and reoxygenation. In vivo analyses have shown that anoxia induced stress proteins (Hsp72, Hsp60, Grp94, Hsp60, Hsp27, HO-1); modest changes in the Bcl2/Bax ratio and no change in cleaved caspase-3 expression suggesting resistance to neuronal damage. These results were corroborated with immunohistochemical evidence indicating no damage in turtle brain when subjected to the stress of anoxia and A/R. To understand the functional role of Hsp72, siRNA against Hsp72 was utilized to knockdown Hsp72 in vitro (neuronally enriched primary cell cultures established from the turtle). Knockdown cultures were characterized by increased cell death associated with elevated ROS levels. Silencing of Hsp72 knocks down the expression of Bcl2 and increases the expression of Bax, thereby decreasing the Bcl2/Bax ratio. However, there was no increase in cytosolic Cytochrome c or the expression levels of cleaved Caspase-3. Significant increase in AIF was observed in the knockdown cultures that increase through anoxia and reoxygenation, suggesting a caspase independent pathway of cell death., Expression of the master regulator of hypoxia, HIF1 alpha and its target gene, VEGF, were analyzed at the mRNA and protein levels. The results showed no significant increase in HIF-1 alpha levels but anoxia VE GF The levels of stress proteins and VEGF returned to control levels during reoxygenation suggesting robust ROS protection mechanisms through reoxygenation. The present study thereby emphasizes Trachemys scripta as an advantageous model to examine anoxia and reoxygenation survival without major damage to the brain due to it's modulation of molecular mechanisms.
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Date Issued
2008
PURL
http://purl.flvc.org/FAU/165943
Subject Headings
Turtles, Physiology, Anoxemia, Proteins, Chemical modification, Oxygen, Physiological effect, Molecular neurobiology
Format
Document (PDF)
Methionine sulfoxide reductase A (MsrA) and aging in the anoxia-tolerant freshwater turtle (Trachemys scripta)
Title
Methionine sulfoxide reductase A (MsrA) and aging in the anoxia-tolerant freshwater turtle (Trachemys scripta).
Creator
Bruce, Lynsey Erin., Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description
The enzyme Methionine sulfoxide reductase A (MsrA) repairs oxidized proteins, and may act as a scavenger of reactive oxygen species (ROS), making it a potential therapeutic target for age-related neurodegenerative diseases. The anoxia-tolerant turtle offers a unique model to observe the effects of oxidative stress on a system that maintains neuronal function following anoxia and reoxygenation, and that ages without senescence. MsrA is present in both the mitochondria and cytosol, with protein...
Show moreThe enzyme Methionine sulfoxide reductase A (MsrA) repairs oxidized proteins, and may act as a scavenger of reactive oxygen species (ROS), making it a potential therapeutic target for age-related neurodegenerative diseases. The anoxia-tolerant turtle offers a unique model to observe the effects of oxidative stress on a system that maintains neuronal function following anoxia and reoxygenation, and that ages without senescence. MsrA is present in both the mitochondria and cytosol, with protein levels increasing respectively 3- and 4-fold over 4 hours of anoxia, and remaining 2-fold higher than basal upon reoxygenation. MsrA was knocked down in neuronally-enriched cell cultures via RNAi transfection. Propidium iodide staining showed no significant cell death during anoxia, but this increased 7-fold upon reoxygenation, suggesting a role for MsrA in ROS suppression during reperfusion. This is the first report in any system of MsrA transcript and protein levels being regulated by oxygen levels.
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Date Issued
2010
PURL
http://purl.flvc.org/FAU/2683139
Subject Headings
Oxidation-reduction reaction, Proteins, Chemical modification, Turtles, Physiology, Oxygen, Physiological effect, Aging, Molecular aspects
Format
Document (PDF)
Nest-to-surf mortality of loggerhead (Caretta caretta) sea turtle hatchlings on Florida’s east coast in 2016
Title
Nest-to-surf mortality of loggerhead (Caretta caretta) sea turtle hatchlings on Florida’s east coast in 2016.
Creator
Erb, Victoria, Wyneken, Jeanette, Florida Atlantic University, Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description
Worldwide, sea turtles are especially vulnerable immediately after emerging from nests. Many monitoring programs measure hatchling production from nest inventories. These inventories rarely account for mortality occurring post-emergence, leaving an incomplete estimate of hatchling production. This study addresses the nest-to-surf data gap for Florida’s east coast nesting assemblages of loggerhead sea turtles (Caretta caretta). Five locations were surveyed during the 2016 nesting season by...
Show moreWorldwide, sea turtles are especially vulnerable immediately after emerging from nests. Many monitoring programs measure hatchling production from nest inventories. These inventories rarely account for mortality occurring post-emergence, leaving an incomplete estimate of hatchling production. This study addresses the nest-to-surf data gap for Florida’s east coast nesting assemblages of loggerhead sea turtles (Caretta caretta). Five locations were surveyed during the 2016 nesting season by using infrared time-lapse imagery, night vision optics, and track maps. Over all beaches, 7.6% of the observed hatchlings did not survive to reach the water. Mortality sources varied by location. Observed predators included: foxes, bobcats, yellow-crowned night herons, ghost crabs, and gulls. Hatchling disorientation and misorientation occurred more frequently in urban areas than natural areas. Factors including number of hatchlings emerging, nest-to-surf distance, and urbanization may help managers estimate nest-to-surf mortality. This study will improve life history models that serve as foundations of conservation management.
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Date Issued
2017
PURL
http://purl.flvc.org/fau/fd/FA00004934, http://purl.flvc.org/fau/fd/FA00004934
Subject Headings
Sea turtles--Mortality--Florida., Loggerhead turtle--Mortality., Predation (Biology), Sea turtles--Orientation., Animal navigation., Fire ants--Venom--Physiological effect.
Format
Document (PDF)
Potential therapies and neuroprotective cascades in anoxia tolerant freshwater turtle Trachemys scripta ellegans
Title
Potential therapies and neuroprotective cascades in anoxia tolerant freshwater turtle Trachemys scripta ellegans.
Creator
Nayak, Gauri., Charles E. Schmidt College of Science, Department of Biomedical Science
Abstract/Description
Mammalian neurons exhibit extreme sensitivity to oxygen deprivation and undergo rapid and irreversible degeneration when oxygen supply is curtailed. Though several neuroprotective pathways are activated during oxygen deprivation, their analyses are masked by the complex series of pathological events which are triggered simultaneously. Such events can be analyzed in the anoxia tolerant fresh water turtle, which can inherently survive the conditions of oxygen deprivation and post-anoxic...
Show moreMammalian neurons exhibit extreme sensitivity to oxygen deprivation and undergo rapid and irreversible degeneration when oxygen supply is curtailed. Though several neuroprotective pathways are activated during oxygen deprivation, their analyses are masked by the complex series of pathological events which are triggered simultaneously. Such events can be analyzed in the anoxia tolerant fresh water turtle, which can inherently survive the conditions of oxygen deprivation and post-anoxic reoxygenation without brain damage. It is likely in such a model that modulation of a particular molecular pathway is adaptive rather than pathological. The major objective behind this study was to analyze the intracellular signaling pathways mediating the protective effects of adenosine, a potential neuromodulator, and its effect on cell survival by influencing the key prosurvival proteins that prevent apoptosis. In vivo and in vitro studies have shown that adenosine acts as a neuroprotective metabolite and its action can be duplicated or abrogated using specific agonist and antagonists. Stimulating the adenosine receptors using selective A1 receptor agonist N6-cyclopentyladenosine (CPA) activated the presumed prosurvival ERK and P13-K/AKT cascade promoting cell survival, and suppression of the receptor using the selective antagonist DPCPX (8- cyclopentyl-1,3-dipropylxanthine) activated the prodeath JNK and P38 pathways. The complex regulation of the MAPK's/AKT signaling cascades was also analyzed using their specific inhibitors. The inhibiton of the ERK and AKT pathway increased cell death, indicating a prosurvival role, whereas inhibiton of the JNK and p38 pathway increased cell survival in this model. In vitro studies have also shown a high Bcl-2/BAX ratio during anoxia and reoxygenation, indicating a strong resistance to cell death via apoptosis., Silencing of the anti-apoptotic Bcl-2 gene using specific siRNA upregulated levels of prodeath BAX, thus altering the Bcl-2/BAX ratio and elevating cleaved Caspase-3 levels leading to increased cell death. Another promising neuroprotective target which we analyzed was Neuroglobin, which was induced during oxygen crisis and silencing this gene indicated that its plays a major role in modulation of ROS. This study strongly emphasizes the advantages of an alternate animal model in elucidating neuroprotective mechanisms and revealing novel therapeutic targets which could eventually help clinicians to design new stroke therapies based on naturally tolerant organisms.
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Date Issued
2009
PURL
http://purl.flvc.org/FAU/186762
Subject Headings
Turtles, Physiology, Adenosine, Receptors, Cellular signal transduction, Molecular neurobiology, Apoptosis, Research, Cellular control mechanisms
Format
Document (PDF)
Vascular endothelial growth factor (VEGF), BCL-2, and BAX expression in fibropapilloma tumor tissue and skin tissue of sea turtles
Title
Vascular endothelial growth factor (VEGF), BCL-2, and BAX expression in fibropapilloma tumor tissue and skin tissue of sea turtles.
Creator
Bancalari-Schmidlapp, Angela., Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description
In sea turtles, the study of the etiology and development of fibropapillomatosis is not fully understood. Sea turtle fibropapillomatosis is a disease characterized by the proliferation of skin fibropapillomas and occasional internal fibromas. In this study, sea turtle fibropapilloma tumor and healthy tissue samples were used to look at VEGF, BCL-2 and Bax expression. Cancer tumors have a well established pattern of protein expression that involves overexpression of vascular endothelial growth...
Show moreIn sea turtles, the study of the etiology and development of fibropapillomatosis is not fully understood. Sea turtle fibropapillomatosis is a disease characterized by the proliferation of skin fibropapillomas and occasional internal fibromas. In this study, sea turtle fibropapilloma tumor and healthy tissue samples were used to look at VEGF, BCL-2 and Bax expression. Cancer tumors have a well established pattern of protein expression that involves overexpression of vascular endothelial growth factor (VEGF), responsible for the growth of new blood vessels, and a high BCL-2 to Bax ratio that leads to uncontrolled cell proliferation. Real time PCR was used to analyze VEGF expression, and Western blot techniques were used to measure BCL-2 and Bax expression. The results indicated that expression of VEGF was not significantly higher in tumor vs. skin tissue. For the differential expression of BCL-2 and Bax, the results were not in agreement with the established levels found in cancer studies, showing no significant change in BCL-2 expression and significantly higher levels of Bax in tumor vs. healthy tissue.
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Date Issued
2009
PURL
http://purl.flvc.org/FAU/209981
Subject Headings
Sea turtles, Physiology, Cancer, Pathophysiology, Vascular endothelial growth factors, Pathophysiology, Cellular signal transduction
Format
Document (PDF)
comparison of the ontogeny of energy consumption in leatherback, Dermochelys coriacea and olive ridley, Lepidochelys olivacea sea turtle hatchlings
Title
A comparison of the ontogeny of energy consumption in leatherback, Dermochelys coriacea and olive ridley, Lepidochelys olivacea sea turtle hatchlings.
Creator
Jones, T. Todd, Florida Atlantic University, Lutz, Peter L., Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description
Changes in activity related oxygen consumption and energy partitioning were measured in leatherback and olive ridley sea turtle hatchlings over their first month after nest emergence. Leatherbacks emerge with about 75--90 KJ of energy in the residual yolk at their disposal for growth and movement. In comparison, the residual yolk energy reserves for the olive ridley are estimated to be much less (45 KJ). In leatherbacks resting specific oxygen consumption rates decreased by 53% over the first...
Show moreChanges in activity related oxygen consumption and energy partitioning were measured in leatherback and olive ridley sea turtle hatchlings over their first month after nest emergence. Leatherbacks emerge with about 75--90 KJ of energy in the residual yolk at their disposal for growth and movement. In comparison, the residual yolk energy reserves for the olive ridley are estimated to be much less (45 KJ). In leatherbacks resting specific oxygen consumption rates decreased by 53% over the first post-hatching month (0.0065 ml O2 min-1 g-1--0.0031 ml O2 min-1 g-1), while for ridleys the fall was 32% (0.0038 ml O2 min-1 g-1--0.0026 ml O2 min-1 g-1). Greater differences were seen in aerobic scope. For olive ridleys the factorial aerobic scope doubled over the first month but there was no significant increase in the leatherback's factorial aerobic scope. Leatherback hatchlings gained on average 33% body mass (10 g) over the first week however 70 to 80% of this increase was due to water accumulation. The differences in aerobic scope and energy reserves are related to differences in early life ecological stratagems of these species.
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Date Issued
2004
PURL
http://purl.flvc.org/fcla/dt/13139
Subject Headings
Sea turtles--Ecology, Animal behavior, Ontogeny, Developmental biology, Adaptation (Physiology), Ecophysiology
Format
Document (PDF)
Fire ants on sea turtle nesting beaches in South Florida, USA, and ST. Croix, USVI
Title
Fire ants on sea turtle nesting beaches in South Florida, USA, and ST. Croix, USVI.
Creator
Romais, Danielle K., Wetterer, James K., Charles E. Schmidt College of Science, Department of Biological Sciences
Abstract/Description
The red imported fire ant, Solenopsis invicta, is a South American native introduced in Alabama in the early 20th century. This predatory species has rapidly spread throughout the southeastern US and parts of the West Indies, inflicting great ecological and economic damage. For example, Solenopsis invicta is known to attack the eggs and hatchlings of ground nesting birds and reptiles. The ants swarm into the nests attacking hatchlings and diminishing their chance for survival. My thesis...
Show moreThe red imported fire ant, Solenopsis invicta, is a South American native introduced in Alabama in the early 20th century. This predatory species has rapidly spread throughout the southeastern US and parts of the West Indies, inflicting great ecological and economic damage. For example, Solenopsis invicta is known to attack the eggs and hatchlings of ground nesting birds and reptiles. The ants swarm into the nests attacking hatchlings and diminishing their chance for survival. My thesis research aimed to survey the distribution of ants on sea turtle nesting beaches in South Florida and St. Croix, USVI, and to evaluate the possible threat of Solenopsis invicta and other predatory ants to sea turtle hatchlings.
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Date Issued
2013
PURL
http://purl.flvc.org/fau/fd/FA0004052
Subject Headings
Biological invasions, Fire ants -- Venom -- Physiological effect, Predation (Biology), Sea turtles -- Florida -- Mortality, Sea turtles -- St. Croix -- Mortality, Wildlife conservation -- Florida, Wildlife conservation -- St. Croix
Format
Document (PDF)