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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
321

A global revision of the nongeniculate coralling algal genere Porolithon Foslie (defunct) and Hydrolithon Foslie (Corallinales, Rhodophyta).

Maneveldt, Gavin W January 2005 (has links)
The purpose of this thesis was to provide a revision and characterization of the species of nongeniculate coralline algae previously ascribed to the now defunct genus Porolithon / to provide a modern account of selected taxa from the genus Hydrolithon and descriptions of taxa found to conform the generic delimitation of Hydrolithon and to use a phenetic cluster analysis to determine the taxonomic relationships between the various taxa ascribed to the genera Polorithon and Hydrolithon.
322

The ecology of bioeroding sponges on Caribbean coral reefs

Gonzalez Rivero, Manuel Alejandro January 2011 (has links)
Sponges contribute to large number of functions in coral reef ecosystems. Among these, bioerosion is perhaps one of the most widely studied, largely due to the important contribution of excavating sponges to the carbonate budget on coral reefs (up to 95 % of the total internal bioerosion). Despite our current knowledge, much of the literature is centred on individual-based observations, and little is known about their ecological role and interactions with other reef taxa in complex coral reef systems. The aim of this thesis was to quantify the ecological interactions of bioeroding sponges with major reef taxa by scaling up individual observations to population and ecosystem-based approaches. A cosmopolitan, abundant and highly competitive bioeroding sponge from Glover’s Atoll, Belize (Cliona tenuis) was used as model species. Monitoring of C. tenuis populations throughout 2009 indicated a trade-off between reproduction and growth, with the highest growth rates (31.4 ± 5.6 mm.y–1) occurring in summer, and a peak in reproductive output during winter. Populations typically show strong left-skewed size frequency distributions, mostly represented by juvenile-size individuals (46%), suggesting that regulating mechanisms (e.g. competition and predation) may be acting in constraining the transition of juveniles to adult sizes. Long-term in situ manipulations showed no effect of predation, yet competition with macroalgae significantly reduced the size of the sponge by 38% ± 11% (SE). While C. tenuis exhibit high growth and recruitment rates that could theoretically result in rapid population growth, the likelihood of sponges forming an alternative stable state as reefs sustain greater levels of disturbance is unclear. An analytical modelling approach of the interplay between macroalgae, coral and sponge was used to explore the likelihood of alternate stable states. The results show that irrespective of successful sponge invasion, inclusion of this third antagonist (in the interplay between coral and macroalgae) can qualitatively affect the likelihood of alternative stable state. The model exhibits emergent properties suggestive of intransitivity between the three competing taxa. Despite the potential of C. tenuis to benefit from disturbance, there are few cases in the literature reporting increases in bioeroding sponge abundance followed disturbance. Therefore, regulating mechanisms such as competition with other taxa, recruitment limitation or mortality are expected to exert demographic control on the populations of bioeroding sponges when space limitation is relaxed due to coral mortality. To determine processes regulating sponge populations, an individual-based spatial modelling approach was used to simulate the population dynamics of C. tenuis in a dynamic ecosystem environment. Using an orthogonal hypothesis testing approach, it was found that competition, and to a lesser extend partial mortality of the sponge tissue, largely regulate the population structure of C. tenuis. While reductions in coral cover may temporarily favour the rapid colonization by sponges, the competitive superiority of macroalgae may steal the opportunity from the opportunists.
323

Taxonomy and ecology of the deep-pelagic fish family Melamphaidae, with emphasis on interactions with a mid-ocean ridge system

Unknown Date (has links)
Much of the world's oceans lie below a depth of 200 meters, but very little is known about the creatures that inhabit these deep-sea environments. The deep-sea fish family Melamphaidae (Stephanoberyciformes) is one such example of an understudied group of fishes. Samples from the MAR-ECO (www.mar-eco.no) project represent one of the largest melamphaid collections, providing an ideal opportunity to gain information on this important, but understudied, family of fishes. The key to the family presented here is the first updated, comprehensive key since those produced by Ebeling and Weed (1963) and Keene (1987). Samples from the 2004 MAR-ECO cruise and the U.S. National Museum of Natural History provided an opportunity to review two possible new species, the Scopelogadus mizolepis subspecies, and a Poromitra crassiceps species complex. Results show that Scopeloberyx americanus and Melamphaes indicoides are new species, while the two subspecies of Scopelogadus mizolepis are most likely o nly one species and the Poromitra crassiceps complex is actually several different species of Poromitra. Data collected from the MAR-ECO cruise provided an opportunity to study the distribution, reproductive characteristics and trophic ecology of the family Melamphaidae along the Mid-Atlantic Ridge (MAR). Cluster analysis showed that there are five distinct groups of melamphaid fishes along the MAR. This analysis also supported the initial observation that the melamphaid assemblage changes between the northern and southern edges of an anti-cyclonic anomaly that could be indicative of a warm-core ring. Analysis of the reproductive characteristics of the melamphaid assemblage revealed that many of the female fishes have a high gonadosomatic index (GSI) consistent with values found for other species of deep-sea fishes during their spawning seasons. / This may indicate that melamphaids use this ridge as a spawning ground. Diets of the melamphaid fishes were composed primarily of ostracods, a mphipods, copepods and euphausiids. Scopelogadus was the only genus shown to have a high percent of gelatinous prey in their digestive system, while Melamphaes had the highest concentration of chaetognaths. This work presents data on the ecology and taxonomy of the family Melamphaidae and provides a strong base for any future work on this biomass-dominant family of fishes. / by Kyle Allen Bartow. / Thesis (Ph.D.)--Florida Atlantic University, 2010. / Includes bibliography. / Electronic reproduction. Boca Raton, Fla., 2010. Mode of access: World Wide Web.
324

Grazing effects of herbivorous fishes and juvenile green turtles (Chelonia Mydas) on macroalgal communities

Unknown Date (has links)
The impact of grazers on the primary production of marine ecosystems has largely been explored in tropical environments. A number of studies support theories on the functional importance of grazers in the community structure of coral reefs. However, large-bodied grazers, like juvenile green turtles, co-occur with herbivorous fishes in subtropical and tropical regions throughout the world and we know little about their combined impact on macroalgal communities and whether they compete for macroalgal resources. My dissertation research was composed of four studies that were conducted simultaneously to further our understanding of plant/herbivore interactions in marine ecosystems. Studies were conducted at the Trident Basin, a non-public military facility within the Port Canaveral Inlet at Cape Canaveral, Florida, USA. The macroalgal study (Chapter 1), determined the spatial and temporal distribution of the macroalgal community. The foraging habits of juvenile green turtles were compared with the macroalgal abundance within the Basin and over time (Chapter 2). Selection ‘for’ specific macroalgal species (based on their availability in the macroalgae study) was used to determine the level of overlap and/or partitioning of resources among herbivorous fishes and juvenile green turtles (Chapter 3). The final empirical study (Chapter 4) measured the impact on thallus height, diameter and/or branching of macroalgae as well as the macroalgal community composition from caging experiments that excluded herbivorous fishes and juvenile green turtles. The algal community was predominantly composed of nine red and green macroalgal species that were persistent year-round. Grazer-resistant macroalgae were rarely observed. Green turtles foraged on many of these same macroalgae but also opportunistically foraged on flotsam, including anthropogenic debris (e.g., plastic). The gut content of the major herbivorous fishes in the community (Abudefduf saxatilis, Archosargus probatocephalus, Diplodus holbrooki, and Lagodon rhomboides) foraged as omnivores depending on where they were captured within the Basin area or their size. All herbivores showed selection for less abundant green algae (i.e., Ulva spp.). Results of the exclusion of juvenile green turtles and large herbivorous fishes in caging experiments suggest that grazing by these large-bodied herbivores had no impact on the composition of the macroalgal community and little impact on the morphological structure of the macroalgal species that were examined. Collectively these four studies contribute to a better understanding of how multiple grazers have evolved to forage in macroalgal communities without detrimental effects on their food resources. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection
325

Nematocyst replacement in the sea anemone Aiptasia Pallida following predation by Lysmata Wurdemanni: an inducible defense?

Unknown Date (has links)
The sea anemone Aiptasia pallida is a biological model for anthozoan research. Like all cnidarians, A. pallida possesses nematocysts for food capture and defense. Studies have shown that anthozoans, such as corals, can rapidly increase nematocyst concentration when faced with competition or predation, suggesting that nematocyst production may be an induced trait. The potential effects of two types of tissue damage, predator induced (Lysmata wurdemanni) and artificial (forceps), on nematocyst concentration was assessed. Nematocysts were identified by type and size to examine the potential plasticity associated with nematocyst production. While no significant differences were found in defensive nematocyst concentration between shrimp predation treatments versus controls, there was a significant difference in small-sized nematocyst in anemones damaged with forceps. The proportions of the different types of nematocysts between treatment types were also found to be different suggesting that nematocyst production in A. pallida is a plastic trait. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2014. / FAU Electronic Theses and Dissertations Collection
326

Tropical crustose coralline algal community and individual growth responses to light and elevated pCO2

Unknown Date (has links)
Crustose coralline algae (CCA) are important reef stabilizers and their susceptibility to anthropogenic climate change and ocean acidification (OA) is of concern. Ocean acidification effects on benthic algal communities were determined by the response of CCA, fleshy macroalgae and microalgae to the interaction of pCO2 and light. I examined if elevated pCO2 and light influences CCA dominance by assessing their growth, recruitment and calcification. Elevated pCO2 under natural reef diurnal CO2 cycles did not significantly affect CCA percent cover, calcification rates or survival of adult CCA lobes. No significant community pCO2 effects were observed, rather light controlled dominance. The percent cover of microalgae increased in highlight, while CCA increased in the shade. My results indicate that algal response to irradiance is a more significant driver of reef benthic algal change than pCO2 levels predicted for 2100; however, this conclusion should be corroborated in longer-term and in field experiments. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2015. / FAU Electronic Theses and Dissertations Collection
327

A elaboração do discurso no Romancero Gitano de Castelnuovo-Tedesco / Lorca /

Rocha Júnior, Atilio Goltardo da, 1983- January 2015 (has links)
Orientador: Gisela Gomes Pupo Nogueira / Banca: Martha L. Herr / Banca: Margareth dos Santos / Resumo: No presente trabalho buscamos refletir a respeito de alguns dos diversos procedimentos extramusicais e interdisciplinares envolvidos na confecção da obra musical Romancero Gitano, de Autoria de Mario Castelnuovo-Tedesco com textos de Federico Garcia Lorca. Para o cumprimento desta tarefa foram considerados procedimentos como retórica e word-painting, bem como levantamento de dados biográficos de compositor e poeta, análises técnico -musicais de cada um dos movimentos da obra e leituras poéticas dos textos / Abstract: In the present work our aim was to reflect on some of the various extra musical and interdisciplinary procedures involved in the confection of the musical work Romancero Gitano, Mario Castelnuovo-Tedesco's authorship, with texts by Federico Garcia Lorca. To achieve this aim we have considered procedures such as rhetoric and word-painting, as well as research on biographical data about composer and poet, technical -musical analysis of each one of the movements of the work and poetical readings of the texts / Mestre
328

Some psychosocial characteristics of out-patients whose cases were reopened two or more times in the Veterans Administration, Mental Hygiene Clinic, Coral Gables, Florida.

Glazer, Herbert Philip. Unknown Date (has links)
No description available.
329

Os ditirambos de Baquílides: um poeta entre dois mundos / The dithyrambs of Bacchylides: a poet between two worlds

Mello, Mariana do Amaral 13 August 2012 (has links)
Este trabalho apresenta uma tradução, seguida de comentários, das seis odes de Baquílides que chegaram aos dias atuais agrupadas sob o rótulo de ditirambos, embora essa classificação seja hoje objeto de debate. O estudo dos poemas tem como foco a sua linguagem, sobretudo a abundante ocorrência de epítetos que nela se nota, traço já reconhecidamente característico na obra de Baquílides. Procura-se por meio da observação detalhada de tais termos delinear traços peculiares do estilo do poeta, os quais contribuem para conferir, no mínimo, unidade estilística a um corpus díspar do ponto de vista da estrutura de cada ode. A partir do mesmo processo, pretende-se ainda analisar o modo como os epítetos em Baquílides dialogam com aqueles das demais tradições poéticas gregas, principalmente os da épica homérica. São considerados, enfim, também como ponto de contato com as tradições aparentemente privilegiadas pelo poeta, o tratamento que ele dispensa aos mitos gregos e as escolhas por ele feitas nesse sentido, questões que podem colaborar para nossa compreensão do gênero poético ao qual seus supostos ditirambos pertencem, a mélica coral grega. / This work presents a translation, followed by comments, from the six odes of Bacchylides which survived under the label of dithyrambs, although this classification is nowadays a disputed issue. The study of the poems focuses on their language, especially on the abundant occurrence of epithets that can be noted, a characteristic feature usually recognized in the work of Bacchylides. Through a detailed observation of such terms, we aim at outlining peculiar traces of the poet\'s style, which contribute to give, at least, a stylistic unity to a diverse corpus regarding the structure of each ode. Using the same process, we intend also to examine how the epithets in Bacchylides dialogue with the ones from other Greek poetic traditions, especially the ones from Homeric epic. We take under consideration, finally, as a point of contact with the traditions apparently privileged by the poet, the way he treats Greek myths and the choices he makes in this regard, things that may help our understanding of the poetic genre to which his alleged dithyrambs belong, the Greek choral melic.
330

Microhabitat Association of Cryptobenthic Reef Fishes (Teleostei: Gobiidae) in the Central Red Sea

Troyer, Emily 05 1900 (has links)
Knowledge of biodiversity within an ecosystem is essential when trying to understand the function and importance of that ecosystem. A challenge when assessing biodiversity of reef habitats is cryptobenthic fishes, which encompass many groups that have close associations with the substrate. These fishes can be behaviorally cryptic, by seeking refuge within the reef matrix, or visually cryptic, using cryptic coloration to match the surrounding habitat. These factors make visual surveys inadequate for sampling these fishes. One such group of cryptobenthic fishes are the gobies, family Gobiidae, which currently represent over 1600 species, although new species are continually being discovered. Gobies are often small (less than 5 cm), and many species will be associated with a very specific microhabitat type. Due to the understudied nature of the Red Sea, little is known about habitat preferences of gobies within the region. In order to determine the differences in goby community structure within the central Red Sea, fishes were sampled at one reef using 1 m² enclosed rotenone stations from three distinct microhabitats: hard coral, rubble, and sand. Following collection, specimens were photographed and sequenced using COI, to aid in species identification. 232 individuals were collected representing 31 species of goby. Rubble microhabitats were found to host the majority of collected gobies (69%), followed by hard coral (20.6%), then sand (9.9%). Goby assemblages in the three microhabitats were significantly different from each other, and evidence of habitat-specialists was found. These results provide essential baseline information about the ecology of understudied cryptobenthic fishes that can be used in future large-scale studies in the Red Sea region.

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