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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.
21

The air-bladder and pulmonary and systematic circulation of Amia Calva L., together with a general description of the fish.

Graham, Annie Philathea. January 1939 (has links)
No description available.
22

Paleontologia de vertebrados da transição entre os Grupos Tubarão e Passa Dois (Neopaleozóico) no centro-leste do Estado de São Paulo / Paleontology of vertebrates from the transition between the Tubarão and Passa Dois Groups (Neopaleozoic) in the central-eastern São Paulo State

Artur Chahud 26 June 2007 (has links)
O centro-leste do Estado de São Paulo expõe boa parte da seção neopaleozóica da Bacia do Paraná, com sedimentos do Grupo Tubarão (Subgrupo Itararé e Formação Tatuí) e o Grupo Passa Dois (formações Irati e Corumbataí). Na região entre Leme e Capivari e na região do Domo de Pitanga, entre Piracicaba e Ipeúna, a transição entre as formações Tatuí e Irati é caracterizada comumente por arenitos relativamente grossos e mal selecionados (arenitos com grânulos, arenitos conglomeráticos e conglomerados), abundantemente fossilíferos em contato abrupto com os folhelhos síltico-argilosos da Formação Irati. O presente trabalho concentrou-se no estudo de paleovertebrados paleozóicos aplicado à interpretação paleontológica, sedimentológica e estratigráfica da transição entre os grupos Tubarão e Passa Dois. O conteúdo fóssil identificado compreende escamas, dentes e partes ósseas de vários tipos de peixes, de água doce e salgada, e de possíveis tetrápodes. Os Chondrichthyes são representados por duas variedades de dentes cladodontes; vários tipos de dentes do Xenacanthiformes ?Pleuracanthus? albuquerquei Silva Santos, 1946; dentes de Orodontiformes; dentes de duas espécies de Petalodontiformes, a primeira, e mais comum, Itapyrodus punctatus Silva Santos, 1990 e a segunda, representada por um único exemplar, uma espécie indeterminada. O material ainda inclui um espinho de nadadeira dorsal de Ctenacanthiformes adulto e uma possível escama placóide. A fauna de Osteichthyes é a mais abundante, sendo composta de dentes e escamas ganóides de Paleonisciformes e escamas cosmóides de Actinistia. São observados grandes dentes labirintodontes (provenientes de tetrápodes primitivos e/ou? peixes Rhipidistia) e partes ósseas atribuídas a peixes e/ou possíveis anfíbios. Os fósseis estão normalmente dispersos e desarticulados e os elementos ósseos fragmentados e desgastados. Mesmo assim, foram encontrados dentes de animais continentais - labirintodontes e Xenacanthiformes, com diferentes tipos de preservação, o que indicaria uma influência fluvial. A mistura de elementos marinhos, como Petalodontes, e continentais sugere um caráter marinho costeiro com forte influência continental para a transição entre as unidades. Os estudos tafonômicos sugerem que a camada de estudo é um depósito residual, resultado direto do retrabalhamento por ondas. Portanto, a transição Tatuí - Irati faz parte da evolução deposicional da Formação Irati. Sugere-se que ela seja reconhecida como uma fácies basal local, de grande importância paleontológica e estratigráfica no centro-leste do Estado de São Paulo. / A good part of the Neopaleozoic section of the Paraná basin is well-exposed in central-east Sao Paulo, Brazil, represented by sedimentary rocks of the Tubarão Group (Itararé Subgroup and Tatuí Formation) and the Passa Dois Group (Irati and Corumbataí formations). Between Leme and Capivari and in the area of the Pitanga Dome, between Piracicaba and Ipeúna, the transition between the Tatuí and Irati formations commonly is characterized by abundantly fossiliferous, poorly sorted, relatively coarse sandstones (sandstones with granules, conglomeratic sandstones and conglomerate) in abrupt contact with silty shale of the Irati Formation. The present work concentrated on the study of Palaeozoic palaeovertebrates and their significance for paleontological, sedimentological and stratigraphical interpretations of the transition between the Tubarão and Passa Dois groups. The identified fossil content consists of scales, teeth and bony parts from several types of fish, from fresh and salt water, as well as from possible tetrapods. Chondrichthyes are represented by two varieties of cladodont teeth; several types of teeth of the xenacanth ?Pleuracanthus? albuquerquei Silva Santos, 1946; teeth of Orodontiformes; teeth of two species of Petalodontiformes, the first, and more common, Itapyrodus punctatus Silva Santos, 1990, and the other, represented by a single specimen, an unidentified species. The material also includes a fin spine of an adult Ctenacanthiformes and a possible placoid scale. The fauna of Osteichthyes is more abundant, being composed of teeth and ganoid scales of Paleonisciformes and cosmoid scales of Actinistia. Also observed are large labyrinthodont teeth (from primitive tetrapods and/or rhipidistid fish) and bony parts attributed to fish and/or possible amphibians. The fossils are usually disarticulated and dispersed and the bony elements fragmented and abraded. Even so, teeth of continental animals - labyrinthodonts and Xenacanthiformes, were found with different types of preservation, which is indicative of a fluvial influence. The mixture of marine elements, like petalodonts, and continental elements suggests a nearshore character with a strong continental influence for the transition between the units. Taphonomic studies suggest that the studied layer is a residual (lag) deposit that resulted directly from reworking by waves. Thus, the Tatuí - Irati transition is part of the depositional evolution of the early Irati Formation. It is therefore suggested that the transition be recognized as a local basal facies of this formation of great paleontological and stratigraphical importance in the central-eastern part of the state of Sao Paulo.
23

Paleontologia de vertebrados da transição entre os Grupos Tubarão e Passa Dois (Neopaleozóico) no centro-leste do Estado de São Paulo / Paleontology of vertebrates from the transition between the Tubarão and Passa Dois Groups (Neopaleozoic) in the central-eastern São Paulo State

Chahud, Artur 26 June 2007 (has links)
O centro-leste do Estado de São Paulo expõe boa parte da seção neopaleozóica da Bacia do Paraná, com sedimentos do Grupo Tubarão (Subgrupo Itararé e Formação Tatuí) e o Grupo Passa Dois (formações Irati e Corumbataí). Na região entre Leme e Capivari e na região do Domo de Pitanga, entre Piracicaba e Ipeúna, a transição entre as formações Tatuí e Irati é caracterizada comumente por arenitos relativamente grossos e mal selecionados (arenitos com grânulos, arenitos conglomeráticos e conglomerados), abundantemente fossilíferos em contato abrupto com os folhelhos síltico-argilosos da Formação Irati. O presente trabalho concentrou-se no estudo de paleovertebrados paleozóicos aplicado à interpretação paleontológica, sedimentológica e estratigráfica da transição entre os grupos Tubarão e Passa Dois. O conteúdo fóssil identificado compreende escamas, dentes e partes ósseas de vários tipos de peixes, de água doce e salgada, e de possíveis tetrápodes. Os Chondrichthyes são representados por duas variedades de dentes cladodontes; vários tipos de dentes do Xenacanthiformes ?Pleuracanthus? albuquerquei Silva Santos, 1946; dentes de Orodontiformes; dentes de duas espécies de Petalodontiformes, a primeira, e mais comum, Itapyrodus punctatus Silva Santos, 1990 e a segunda, representada por um único exemplar, uma espécie indeterminada. O material ainda inclui um espinho de nadadeira dorsal de Ctenacanthiformes adulto e uma possível escama placóide. A fauna de Osteichthyes é a mais abundante, sendo composta de dentes e escamas ganóides de Paleonisciformes e escamas cosmóides de Actinistia. São observados grandes dentes labirintodontes (provenientes de tetrápodes primitivos e/ou? peixes Rhipidistia) e partes ósseas atribuídas a peixes e/ou possíveis anfíbios. Os fósseis estão normalmente dispersos e desarticulados e os elementos ósseos fragmentados e desgastados. Mesmo assim, foram encontrados dentes de animais continentais - labirintodontes e Xenacanthiformes, com diferentes tipos de preservação, o que indicaria uma influência fluvial. A mistura de elementos marinhos, como Petalodontes, e continentais sugere um caráter marinho costeiro com forte influência continental para a transição entre as unidades. Os estudos tafonômicos sugerem que a camada de estudo é um depósito residual, resultado direto do retrabalhamento por ondas. Portanto, a transição Tatuí - Irati faz parte da evolução deposicional da Formação Irati. Sugere-se que ela seja reconhecida como uma fácies basal local, de grande importância paleontológica e estratigráfica no centro-leste do Estado de São Paulo. / A good part of the Neopaleozoic section of the Paraná basin is well-exposed in central-east Sao Paulo, Brazil, represented by sedimentary rocks of the Tubarão Group (Itararé Subgroup and Tatuí Formation) and the Passa Dois Group (Irati and Corumbataí formations). Between Leme and Capivari and in the area of the Pitanga Dome, between Piracicaba and Ipeúna, the transition between the Tatuí and Irati formations commonly is characterized by abundantly fossiliferous, poorly sorted, relatively coarse sandstones (sandstones with granules, conglomeratic sandstones and conglomerate) in abrupt contact with silty shale of the Irati Formation. The present work concentrated on the study of Palaeozoic palaeovertebrates and their significance for paleontological, sedimentological and stratigraphical interpretations of the transition between the Tubarão and Passa Dois groups. The identified fossil content consists of scales, teeth and bony parts from several types of fish, from fresh and salt water, as well as from possible tetrapods. Chondrichthyes are represented by two varieties of cladodont teeth; several types of teeth of the xenacanth ?Pleuracanthus? albuquerquei Silva Santos, 1946; teeth of Orodontiformes; teeth of two species of Petalodontiformes, the first, and more common, Itapyrodus punctatus Silva Santos, 1990, and the other, represented by a single specimen, an unidentified species. The material also includes a fin spine of an adult Ctenacanthiformes and a possible placoid scale. The fauna of Osteichthyes is more abundant, being composed of teeth and ganoid scales of Paleonisciformes and cosmoid scales of Actinistia. Also observed are large labyrinthodont teeth (from primitive tetrapods and/or rhipidistid fish) and bony parts attributed to fish and/or possible amphibians. The fossils are usually disarticulated and dispersed and the bony elements fragmented and abraded. Even so, teeth of continental animals - labyrinthodonts and Xenacanthiformes, were found with different types of preservation, which is indicative of a fluvial influence. The mixture of marine elements, like petalodonts, and continental elements suggests a nearshore character with a strong continental influence for the transition between the units. Taphonomic studies suggest that the studied layer is a residual (lag) deposit that resulted directly from reworking by waves. Thus, the Tatuí - Irati transition is part of the depositional evolution of the early Irati Formation. It is therefore suggested that the transition be recognized as a local basal facies of this formation of great paleontological and stratigraphical importance in the central-eastern part of the state of Sao Paulo.
24

Evolution of modular morphology in actinopterygian pectoral fins

Tissandier, Sylvie. January 2006 (has links)
No description available.
25

Evolution of modular morphology in actinopterygian pectoral fins

Tissandier, Sylvie. January 2006 (has links)
With a generally conserved function for locomotion, paired fins have an extensive evolutionary history that has resulted in highly disparate morphologies in a wide diversity of taxa. Two-dimensional geometric morphometrics offers a means to quantitatively describe disparity and changes in the shape of pectoral fins. Actinopterygians lend themselves well to a study of this nature due to their prolific diversity and prevalence in the fossil record. As a result of changes in skeletal fin structures and the lack of homologous elements throughout the group, three morphological modules are used as the unit of comparison rather than individual elements of the fin. Ordination plots from thin plate spline analyses, including fossil and extant taxa, show correspondence with the actinopterygian phylogeny as trends become apparent through the group. Basal actinopterygians and basal teleosts tend to have a narrow, elongate fin shape. Following a shift in morphospace, derived teleosts have a wider fin base, with an elongate anterior margin of the fin relative to the posterior trailing edge. Linear and squared-change parsimony reconstructions of continuous data allow the phylogeny to be traced through morphospace to approximate the path of pectoral fin evolution. The shift in morphospace occurs at Acanthomorpha, and is correlated with the evolution of a physoclistous swim bladder and a change in the position and orientation of pectoral fins. As a result of these changes, new swimming modes are made available, and the expansion of locomotory modes of Acanthomorpha is here hypothesized to be associated with a sharp increase in pectoral fin disparity.
26

Discovery and characterisation of cytokines involved in T-helper cell responsed in teleosts

Holt, Amy January 2011 (has links)
Much of the research that has been done on the fish immune system has focussed on innate immunity. Very little is known about the adaptive immune system of fish and how it is regulated. This study has identified and characterised key cytokines that had not been found in any teleost species to date involved in T helper 2 (Th2) and T helper 17 (Th17) responses. By exploiting the synteny that exists between the human and zebrafish genomes two IL-4 homologues were identified, and their full length cDNA cloned and sequenced, which were termed IL-4 like (IL-4L) and IL-4 related (IL-4rel). This work describes the finding of what we consider to be the actual IL-4 homologue in fish and establishes reasons why the already published ‘IL-4’ gene in Tetraodon (Li, Shao et al. 2007b) may not in fact be the actual IL-4 homologue of mammals but an IL-4 related (IL-4rel) gene which we have also been able to locate within the zebrafish genome. To help with determining the identity of these genes within fish, recombinant proteins of the IL-4L and IL-4rel genes were produced in zebrafish and the IL-4rel molecule in trout. Preliminary expression studies have displayed some evidence of bioactivity in the zebrafish IL-4L and trout IL-4rel proteins, through their impact on the regulation of various immune related genes. These include IL-1β, IFN-γ, the IFN-γR1 and the IL-4 receptor-α chain. This work has also identified and characterised for the first time in any lower vertebrate, the zebrafish IL-23 p19 subunit, which is very important in Th17 responses. In addition the p19 sequence has been predicted from other available fish genomes (stickleback, Fugu, Tetraodon) for comparison. Expression analysis of this subunit along with the p40 subunit within a zebrafish disease model for tuberculosis shows up regulation of this gene after 1 day.
27

Evaluation of telomere length as an age-marker in marine teleosts

Tsui, Chau-ying., 徐秋映. January 2005 (has links)
published_or_final_version / abstract / Ecology and Biodiversity / Master / Master of Philosophy
28

Molecular characterization and expression of Gq/11 protein in fishes

Radhakrishnan, Varsha, January 2007 (has links)
Thesis (M.S.)--Texas State University-San Marcos, 2007. / Vita. Includes bibliographical references (leaves 68-75).
29

Molecular characterization and expression of Gq/11 protein in fishes /

Radhakrishnan, Varsha, January 2007 (has links)
Thesis (M.S.)--Texas State University-San Marcos, 2007. / Vita. Includes bibliographical references (leaves 68-75).
30

Aspects of the biology of Caffrogobius Caffer (Günter) (Pisces : Teleostei : Gobiidae) in the Eastern Cape

Butler, Graham Stuart January 1981 (has links)
Several strategies used by the gobiid fish Caffrogobius caffer enabling it to colonise the harsh intertidal environment in the eastern Cape were studied. Q. caffer is opportunistic in its use of available food resources and feeds throughout the day with a slight tendency towards crepuscular peaks of feeding activity. The system of space utilisation used by C. caffer is so organised that all individuals of the population have access to patchily distributed food resources. Current velocities occurring over high tide limit the movements of Qo caffer and interpool movements occur only during the initial stages of a rising tide and in the final stages of an ebbing tide when the current velocities are below the tolerance limit of Q. caffer. The epifauna associated with the alga Ulva rigida, which forms an important constituent of the diet of the intermediate size classes of Q. caffer, was examined and it appears that this epifauna is an important source of food to Q. caffer. This report presents the results of the first detailed study of the biology of an intertidal fish in southern Africa.

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