Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 15 of 15 for “"zooxanthellae"”.
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Lipid biomarkers of coral stress : calibration and exploration
… between corals and their algal endosymbionts (zooxanthellae) is easily disrupted by thermal stress, leading to bleaching and eventual mortality. The use of lipid ratios as biomarkers of environmental conditions is well established. Coral biomass contains abundant lipids, and the potential of …
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Lipid biomarkers of coral stress : calibration and exploration
… between corals and their algal endosymbionts (zooxanthellae) is easily disrupted by thermal stress, leading to bleaching and eventual mortality. The use of lipid ratios as biomarkers of environmental conditions is well established. Coral biomass contains abundant lipids, and the potential of …
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Ultraviolet Radiation and Carotenoid Pigmentation in Symbiotic Anthozoans
… photoadaptive response of symbiotic algae (i.e., zooxanthellae) after bleaching. An experiment was conducted to partition the effects of UVA (320 - 400nm), photosynthetically active radiation (PAR; 400-700nm) and host feeding on the pigmentation of bleached and unbleached anemones. This experiment …
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Quantitative tracking of the cellular and skeletal response of the Caribbean coral Orbicella annularis to gradients in marine sewage pollution
… (3D) quantification of the density of zooxanthellae and chromatophore cells within the coral tissues. X-ray computed tomography (BioCT) was used to determine the density of the outermost layer of the coral skeletal being precipitated at the time of sampling in May 2014. Results indicate …
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Chromatophore tissue density and skeletal density banding as a measure of the adaptive response of healthy corals to environmental change
… to enhance the photosynthetic activity of zooxanthellae symbionts and possibly protect the coral animal from harmful ultraviolet (UV) radiation. Yet connections have not previously been drawn between changes in the tissue density of chromatophores and the development of skeletal density …
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Carbon cycling in the Caribbean reef-building coral Orbicella: quantitative evidence for enzymatic control of skeletal density banding and coral-endosymbiont physiological plasticity during seasonal environmental change
… endosymbiont, the unicellular dinoflagellate zooxanthellae. Quantitative image analyses show that both the cellular density of zooxanthellae and the density of the chromatophores change according to positioning on the reef tract, and therefore levels of irradiance to which the host and …
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Microscale Variation in Light Intensity and its Effects on Growth of Juveniles of the Temperate Coral, Oculina Arbuscula
… when Artemia were provided, suggesting that zooxanthellae utilize heterotrophically acquired nutrients in order to maintain stable densities in juveniles while contributing low amounts of photosynthetically fixed nutrients towards the host. Combined, these results indicate that the symbiosis …
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Characterisation of Nitric Oxide Synthase Activity in the Sea Anemone Aiptasia pallida and an Evaluation of Responses to Environmental Stress
… in the sea anemone A. pallida, in the zooxanthellae associated with A. pallida, Symbiodinium spp. and in five scleractinian coral species. Preliminary studies were conducted to characterise NOS from A. pallida. NOS activity of this species was shown to be predominantly cytosolic and …
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Comportamento reprodutivo de Mussismilia hispida (Verril, 1902) (Cnidaria, Anthozoa, Scleractinia)
… times throughout the spawning period. No zooxanthellae were found in pre-spawning oocytes, which characteristically had a large amount of vitelline material and a peripheral germ vesicle.
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The abundance and diversity patterns of seaweed communities on natural and artificial substrata at Sodwana Bay, South Africa
… bleached corals, which may either regain their zooxanthellae and recover, or may die, in which case they generally become overgrown by macroalgae. The nature and dynamics of this algal overgrowth are not well understood. This study was done on Two-Mile Reef, Sodwana Bay, located in the …
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Effects of Temperature stress on coral fluorescence and reflectance
… I nonetheless detected change in the algae’s (zooxanthellae) fluorescence in both A. cervicornis and O. annularis. Fluorometer analyses further demonstrated that the photosystems of the algae (PSII) were damaged by exposure to higher water temperatures, implying that the immediate effect of the …
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Sedimentation threats to Red Sea corals : an ecological study of reefs in the Hurghada Region, Egypt
… to examine changes in community structure.Zooxanthellae density was measured in transplanted corals in field and laboratory conditions to determine the effect of sedimentation on coral bleaching. In addition, direct feeding experiments were performed using fluorescein-isothiocyanate …
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Effects ofUltraviolet Radiation on Newly Settled Recruits of the Reef-building Coral <em>Porites astreoide</em>
… radiation (400-700 nm) need by the symbiotic zooxanthellae in the coral animal.</p> <p>Detrimental effects ofUVR have also been found in coral larvae such as reduced settlement, survival, and lower chlorophyll concentrations. Previous studies indicate that UVR may play a role in survival …
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Phylogeography of Oculina Corals and their Algal Symbionts: Insights into the Origin and Expansion of Oculina Patagonica in the Mediterranean
In a world of rapidly changing environmental conditions, species must effectively respond to their changing habitat or risk extinction. The goal of my dissertation is to elucidate the origins and mechanisms underlying the recent successful population expansion of the invasive coral Oculina …
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Coral skeleton density banding: biotic response to changes in sea surface temperature
Density bands in the CaCO3 (aragonite) skeleton of scleractinian corals are commonly used as chronometers, where crystalline couplets of high and low density bands represent the span of one year. Isotopic analysis of these density bands provides a sensitive reconstructive tool for paleoclimatology …