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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.
1

Ecomorphological guilds and diet of exotrophic anuran tadpoles / Vidette Botha

Botha, Vidette January 2014 (has links)
To test the applicability of anuran tadpole functional ecology with regards to diet as a tool to determine ecosystem function of aquatic habitats, all the presently known as southern Africa anuran species’ tadpoles were assigned to ecomorphological guilds. The data set included 106 anuran tadpole species and 84 variables, which include: 23 habitat; 49 morphological; 9 behavioral; and 3 development (time metamorphosis) related variables. Although the data set for the guild delineation did not include genetic data, a phylogeny (evolutionary approach) was used to obtain a tree where species are grouped together based on shared characteristics, similar to that of a cluster analysis where each cluster or group is a guild. Maximum parsimony was employed with PAUP 4.0b10 to construct consensus trees using heuristic search settings. The phylogenetic/taxonomic affiliation of the species in each ecomorphological guilds’ was also observed by constructing a phylogenetic tree. The 12S and 16S mitochondrial gene sequences were retrieved from Genbank, to represent the major lineages documented in the anurans of southern Africa thus far. The ecomorphological guild delineation was further supported by quantify tadpole gut contents to determine their trophic status. Information on the feeding behavior of four guilds was obtained by analyzing a representative anuran tadpole species from each. The IUCN red list of threatened species was consulted to obtain the conservation status of the 106 anuran species used for this study, which made it possible to determine whether there is a link between species found in the same ecomorphological guilds and those species’ conservation status. Considering the high diversity of anuran species in the Phongolo region (offering access to a variety of tadpole guilds), and the ability to analyse the diatom communities found in the gut contents of tadpoles. A portion of this study supplemented the assessment of ecosystem functioning and management of aquatic resources of the lower Phongolo River and floodplain, by providing information regarding the health. Diatom bioassessment was applied as a tool for inferring water quality. The polygenetic approach proved to be very effective for the guild delineation, permitting the recognition of 10 fully characterized ecomorphological guilds, a number of which corresponded with previously characterized guilds. Terminology had to be produced for three new guilds, based on the guild defining criteria. The polygeny of the anuran species within the guild, although belonging to different genera and families belonged to the same phylogenetic clade. The trophic analysis supports the guild delineation, since a clear distinction could be made between the percentage and combination of materials from each trophic category ingested by tadpoles from different ecomorphological guilds. Even though some similarity can be seen between species, based on the criteria for the endangered status, there was still no true correlation between IUCN status and ecomorphological guild. The fact that the critically endangered, endangered and vulnerable species are distributed over so many guilds further emphasizes the extent of amphibian decline. The majority of the diatom species found in the Phongolo River and floodplain favor brackish water, with a moderate to high electrolyte content. Indicating that the Phongolo River and the section of the floodplain considered for this study had a high salinity. This might be due to the water bodies’ close proximity to the coast. The diatom index scores indicated the presence of organic pollutants and labelled these water bodies as mesotrophic to eutrophic. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2014
2

Ecomorphological guilds and diet of exotrophic anuran tadpoles / Vidette Botha

Botha, Vidette January 2014 (has links)
To test the applicability of anuran tadpole functional ecology with regards to diet as a tool to determine ecosystem function of aquatic habitats, all the presently known as southern Africa anuran species’ tadpoles were assigned to ecomorphological guilds. The data set included 106 anuran tadpole species and 84 variables, which include: 23 habitat; 49 morphological; 9 behavioral; and 3 development (time metamorphosis) related variables. Although the data set for the guild delineation did not include genetic data, a phylogeny (evolutionary approach) was used to obtain a tree where species are grouped together based on shared characteristics, similar to that of a cluster analysis where each cluster or group is a guild. Maximum parsimony was employed with PAUP 4.0b10 to construct consensus trees using heuristic search settings. The phylogenetic/taxonomic affiliation of the species in each ecomorphological guilds’ was also observed by constructing a phylogenetic tree. The 12S and 16S mitochondrial gene sequences were retrieved from Genbank, to represent the major lineages documented in the anurans of southern Africa thus far. The ecomorphological guild delineation was further supported by quantify tadpole gut contents to determine their trophic status. Information on the feeding behavior of four guilds was obtained by analyzing a representative anuran tadpole species from each. The IUCN red list of threatened species was consulted to obtain the conservation status of the 106 anuran species used for this study, which made it possible to determine whether there is a link between species found in the same ecomorphological guilds and those species’ conservation status. Considering the high diversity of anuran species in the Phongolo region (offering access to a variety of tadpole guilds), and the ability to analyse the diatom communities found in the gut contents of tadpoles. A portion of this study supplemented the assessment of ecosystem functioning and management of aquatic resources of the lower Phongolo River and floodplain, by providing information regarding the health. Diatom bioassessment was applied as a tool for inferring water quality. The polygenetic approach proved to be very effective for the guild delineation, permitting the recognition of 10 fully characterized ecomorphological guilds, a number of which corresponded with previously characterized guilds. Terminology had to be produced for three new guilds, based on the guild defining criteria. The polygeny of the anuran species within the guild, although belonging to different genera and families belonged to the same phylogenetic clade. The trophic analysis supports the guild delineation, since a clear distinction could be made between the percentage and combination of materials from each trophic category ingested by tadpoles from different ecomorphological guilds. Even though some similarity can be seen between species, based on the criteria for the endangered status, there was still no true correlation between IUCN status and ecomorphological guild. The fact that the critically endangered, endangered and vulnerable species are distributed over so many guilds further emphasizes the extent of amphibian decline. The majority of the diatom species found in the Phongolo River and floodplain favor brackish water, with a moderate to high electrolyte content. Indicating that the Phongolo River and the section of the floodplain considered for this study had a high salinity. This might be due to the water bodies’ close proximity to the coast. The diatom index scores indicated the presence of organic pollutants and labelled these water bodies as mesotrophic to eutrophic. / MSc (Environmental Sciences), North-West University, Potchefstroom Campus, 2014
3

Caracterização ecomorfológica da comunidade de peixes de duas microbacias do Alto Rio Paraná

Oliveira, Elisa Martins de 09 March 2016 (has links)
Submitted by Alison Vanceto (alison-vanceto@hotmail.com) on 2017-02-07T10:30:44Z No. of bitstreams: 1 TeseEMO.pdf: 7148427 bytes, checksum: 475fdc271961e45dfdde88a0decfaf60 (MD5) / Approved for entry into archive by Camila Passos (camilapassos@ufscar.br) on 2017-02-08T12:04:18Z (GMT) No. of bitstreams: 1 TeseEMO.pdf: 7148427 bytes, checksum: 475fdc271961e45dfdde88a0decfaf60 (MD5) / Approved for entry into archive by Camila Passos (camilapassos@ufscar.br) on 2017-02-08T12:08:38Z (GMT) No. of bitstreams: 1 TeseEMO.pdf: 7148427 bytes, checksum: 475fdc271961e45dfdde88a0decfaf60 (MD5) / Made available in DSpace on 2017-02-08T12:10:27Z (GMT). No. of bitstreams: 1 TeseEMO.pdf: 7148427 bytes, checksum: 475fdc271961e45dfdde88a0decfaf60 (MD5) Previous issue date: 2016-03-09 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / This study examined the ecomorphological pattern ofichthyofauna in two watersheds located on the Upper Paraná River. It was analyzed the ecomorphological variations of species collected from the Beija-Flor stream and Beija-Flor reservoir located in Estação Ecológica de Jataí and Lapa stream located in Área de Proteção Ambiental Corumbataí/Botucatu/Tejubá, to verify interspecific morphological differentiation, the effects oftrophic guilds along the ecomorphological patterns and the effects of water velocity along the ecomorphological standards. Of individuals collected in Estação Ecológica de Jataí, it was selected two Characidium species, on which the ecomorphological variations related to possibility of inter specific morphological differentiation of species of the same genus were analyzed. Considering the common species between the Estação Ecológica de Jataí and the Lapa Stream were observed morphological variables in order to verify the intraspecific morphological differences. Finally these results were related to the meaningof the relation ship between form and function. The main morphological differences found in the individuals of this study were related to the speed of water and feeding habits of the species. The distribution of species in morphological space showed the relation between the ecomorphological attributes and the distribution of species over the water column, where it was possible to characterize the species as demersal, nectobenthicand nektonic species. The relation ship of fish morphology with the water velocity is fundamental. The feeding also contributes with smaller importance in the separation of species in ecomorphological space, but this contribution seems to be because of the presence of these food items is also influenced by the speed of the water. The function of the species in the environmentin which they liveis linked mainly to its trophicniche. / Neste estudo foi analisado o padrão ecomorfológico daictiofauna de duas microbacias localizadas no alto rio Paraná. Foram analisadas as variações ecomorfológicas das espécies coletadas no córrego e represa do Beija-Flor, localizados na Estação Ecológica de Jataí e córrego da Lapa, localizado na Área de Proteção Ambiental Corumbataí/Botucatu/Tejubá, para verificar as diferenças morfológicas interespecíficas, os efeitos das guildas tróficas junto aos padrões ecomorfológicos e os efeitos da velocidade da água junto aos padrões ecomorfológicos. Das espécies coletadas na Estação Ecológica de Jataí, foram selecionadas duas do gênero Characidium, sobre as quais foram analisadas as variações ecomorfológicas relacionadas à possibilidade de existência de diferenciação morfológica interespecífica de espécies pertencentes ao mesmo gênero. Considerando-se as espécies comuns entre a Estação Ecológica de Jataí e o córrego da Lapa, foram observadasas variáveis morfológicas com objetivo deverificar as diferenciações morfológicas intraespecíficas. Por fim, tais resultados foram relacionados ao significado da relação entre forma e função. As principais diferenças morfológicas encontradas nos indivíduos deste estudo foram relacionadas à velocidade da água e ao hábito alimentar das espécies. A distribuição das espécies no espaço morfológico mostrou a relação entre os atributos ecomorfológicos e a distribuição das espécies ao longo da coluna da água, que possibilitou caracterizar as espécies como demersais, nectobentônicas e nectônicas. A relação da morfologia dos peixes com a velocidade da água mostrou-se fundamental. A alimentação aparece com menor importância na separação das espécies no espaço ecomorfológico, mas tal contribuição parece ocorrer devido à presença destes itens alimentares serem influenciados pela velocidade da água. A função das espécies no ambiente em que habitam está ligada, principalmente, ao seu nicho trófico.
4

Biomecânica do comportamento alimentar de girinos de anfíbios anuros / Biomechanics of tadpoles feeding behavior

Sousa, Verônica Thiemi Tsutae de 22 March 2016 (has links)
Submitted by JÚLIO HEBER SILVA (julioheber@yahoo.com.br) on 2017-06-09T18:38:01Z No. of bitstreams: 2 Tese - Verônica Thiemi Tsutae de Sousa - 2016.pdf: 1855796 bytes, checksum: a92374006d1189b1bcac663f0f96a8d0 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2017-06-12T12:21:54Z (GMT) No. of bitstreams: 2 Tese - Verônica Thiemi Tsutae de Sousa - 2016.pdf: 1855796 bytes, checksum: a92374006d1189b1bcac663f0f96a8d0 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2017-06-12T12:21:54Z (GMT). No. of bitstreams: 2 Tese - Verônica Thiemi Tsutae de Sousa - 2016.pdf: 1855796 bytes, checksum: a92374006d1189b1bcac663f0f96a8d0 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-03-22 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Individuals of the same species have morphological, physiological and behavioral characteristics that determine when and where they will exist and how they will interact with individuals of other species. The ecomorphological diversity of anuran tadpoles make them great study subjects, as the resources use patterns (ecology) and the phylogenetic relationships among species can be inferred from the phenotypic properties. The influence of contemporary factors on the structure of tadpoles communities has been intensively studied for decades, but the use patterns and partitioning of food resources, have not received the same attention from researchers. Little is known about the ecology and feeding behavior of tadpoles, including its biomechanics, the influence of abiotic factors on feeding behavior, as well as the behavioral plasticity exhibited by tadpoles in the exploitation of food resources. These issues were investigated during the PhD and the results of the work developed during the course of this period are presented in this Dissertation In the first chapter, we verified whether the carnivorous tadpole of Leptodactylus labyrinthicus would adjust their feeding kinematics to maximize food consumption when feeding on alternative food sources. Our results indicate that, depending on the food source to be explored, the tadpoles may exhibit different feeding behavior: to consume the food particles suspended in the water surface, the tadpoles exhibit the filter-feeding behavior; in contrast, to consume food particles that are attached to submerse surfaces, tadpoles use the scrape feeding behavior. Filtering and scraping feeding behaviors are quantitative and qualitatively distincts, i.e. these feeding behaviors kinematics and the shape of the oral disc during feeding show distinguishable features. In the second chapter, we tested the hypothesis that changes in the water mean temperature would have differential 15 effects on the feeding kinematics of tadpoles of two anuran species: Rhinella schneideri, whose tadpoles are benthic, and Trachycephalus typhonius, whose tadpoles are nektonic. Our results indicate that the temperature affects the kinematics of the scrape feeding behavior. However, the temperature effect on kinematics variables may depend on the species, so the changes are not in the same direction (i.e. temperature may have a positive effect on some kinematic variables but negative effects on others). Finally, in the third chapter, our aim was to verify whether the ecological and morphological influences on feeding behavior reflect the phylogenetic relationship among species. / Indivíduos de uma mesma espécie possuem características morfológicas, fisiológicas e comportamentais que determinam quando e onde eles poderão existir e como interagirão com indivíduos de outras espécies. A diversidade ecomorfológica de girinos de anfíbios anuros os tornam ótimos organismos de estudo, já que os padrões de uso de recursos (ecologia) e as relações filogenéticas entre as espécies podem ser inferidas a partir das propriedades fenotípicas. A influência de fatores contemporâneos sobre a estrutura das comunidades de girinos tem sido intensamente estudada há décadas, mas os padrões de uso e partilha de recursos alimentares não têm recebido a mesma atenção dos pesquisadores. Pouco se sabe sobre a ecologia e o comportamento alimentar dos girinos, incluindo a biomecânica do comportamento alimentar, a influência de fatores abióticos sobre o comportamento alimentar, além da plasticidade comportamental exibida pelos girinos na exploração dos recursos alimentares. Estas questões foram investigadas durante o Doutorado e os resultados do trabalho durante ao longo deste período são apresentados na presente tese, que compreende três capítulos. No primeiro, verificamos se o girino carnívoro de Leptodactylus labyrinthicus ajusta seu comportamento alimentar para maximizar o consumo de alimento obtido a partir de fontes alimentares alternativas. Os resultados indicam que, dependendo da fonte alimentar a ser explorada, os girinos podem adotar comportamentos alimentares distintos: para consumir alimentos disponíveis em suspensão na água, os girinos exibem o comportamento de filtração; já para consumir alimentos aderidos em superfícies submersas, os girinos utilizam o comportamento de raspagem. Tais comportamentos alimentares são discerníveis com relação às suas cinemáticas e aos formatos que o disco oral assume durante a alimentação por filtração e por raspagem. No segundo, testamos a 13 hipótese de que mudanças na temperatura média da água teriam efeitos diferenciais sobre o comportamento alimentar de girinos de duas espécies de anuros: Rhinella schneideri, que possui girinos bentônicos, e Trachycephalus typhonius, cujos girinos são nectônicos. Os resultados indicam que a temperatura afeta a cinemática do comportamento alimentar de raspagem. No entanto, devido à interação entre espécie e temperatura, o efeito da temperatura sobre as variáveis cinemáticas pode não produzir uma variação no mesmo sentido. Finalmente, no terceiro capítulo, nosso objetivo foi o de verificar se a influência dos fatores ecológicos e morfológicos sobre o comportamento alimentar dos girinos reflete as relações filogenéticas entre as espécies.

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