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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

Studies of the Passive Dispersal of Viable Algae and Protozoa by Aquatic and Terrestrial Beetles

Milliger, Larry Edward 08 1900 (has links)
The purpose of the present study was to determine the relative importance of aquatic and terrestrial beetles as possible vehicles in the passive overland dispersal of viable microorganisms.
2

Diversidade de Dytiscidae (Coleoptera) em áreas úmidas do Rio Grande do Sul

Gomes, Julia Gibertoni 14 April 2016 (has links)
Submitted by Daniele Amaral (daniee_ni@hotmail.com) on 2016-09-28T18:58:03Z No. of bitstreams: 1 DissJGG.pdf: 1470736 bytes, checksum: cfeee6371479ec076e217bc18beaaf8b (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2016-10-04T18:28:16Z (GMT) No. of bitstreams: 1 DissJGG.pdf: 1470736 bytes, checksum: cfeee6371479ec076e217bc18beaaf8b (MD5) / Approved for entry into archive by Ronildo Prado (ronisp@ufscar.br) on 2016-10-04T18:28:25Z (GMT) No. of bitstreams: 1 DissJGG.pdf: 1470736 bytes, checksum: cfeee6371479ec076e217bc18beaaf8b (MD5) / Made available in DSpace on 2016-10-04T18:34:06Z (GMT). No. of bitstreams: 1 DissJGG.pdf: 1470736 bytes, checksum: cfeee6371479ec076e217bc18beaaf8b (MD5) Previous issue date: 2016-04-14 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Beetles represented the largest group of animais but end up neglected in ecological studies and much of its wildlife has not described, mainly in tropical areas of great diversity. Dytiscidae, larger family of water beetles, prefers lentic environments, which can be divided according to their hydroperiod in permanent and periodic. The distribution of these ditiscidae were tested in this study in 104 wetlands of Rio Grande do Sul (RS) to detect differences in the composition of each hydroperiod, also serving as a survey of taxa occurring. Were sampled 1905 specimens from 21 genera with the first record in the state of genera Platynectes, Uvarus and Pachydrus. Multivariate Canonical Correspondence Analysis (CCA) found that only biome and hydroperiod influenced the fauna. The differencce of the beta diversity among hydroperiods was significant, showing that varied in composition with each other, and communities in more homogeneous perennial areas than those found in the periodic areas. Despite the difference of the faunal composition richness showed similar values when standardized by rarefaction curve and each hydroperiod presented exclusive taxa. / Representantes do maior grupo de animais, os coleópteros acabam negligenciados em estudos ecológicos e muito da sua fauna ainda não foi descrita, principalmente nas áreas neotropicais de grande diversidade. Dytiscidae, maior família de coleópteros aquáticos, possuem predileção por ambientes lênticos, que podem ser divididos de acordo com seu hidroperíodo em perenes e intermitentes. Foram testadas neste estudo a distribuição desses ditiscideos em 104 áreas úmidas do estado Rio Grande do Sul (RS) para verificar a diferença na composição de cada hidroperíodo, servindo também como levantamento dos táxons ocorrentes. Foram coletados 1905 indivíduos e 21 gêneros, com o primeiro registro no estado dos gêneros Platynectes Régimbart, 1879, Uvarus Guignot, 1939 e Pachydrus Sharp, 1882. Por análise multivariada Correspondência canônica (ACC) constata-se que apenas o bioma e o hidroperíodo influenciaram composição dessa fauna. A diferença da diversidade beta entre os hidroperíodos foi significativa, mostrando que variaram em composição entre si, sendo as comunidades das áreas úmidas perenes mais homogêneas do que as encontradas nas áreas intermitentes. Apesar da diferença da composição faunística, a riqueza quando padronizada, através de curva de rarefação, mostrou valores similares e cada classe de hidroperíodo apresentou táxons exclusivos.
3

Taxonomie, fylogeze a fylogeografie vybraných skupin vodních brouků (Coleoptera: Hydrophilidae, Hydraenidae) karibské oblasti / Taxonomy, phylogeny and phylogeografy of selected groups of aquatic beetles (Coleoptera: Hydrophilidae, Hydraenidae) of the Caribbean region

Deler-Hernández, Albert January 2017 (has links)
This thesis is focused in the representatives of beetle families Hydrophilidae and Hydraenidae of West Indies and adjacent regions. It consists of two parts, the phylogenetic part and the systematic part. The phylogenetic part focuses on the hydrophilid genera Phaenonotum and Crenitulus of Greater Antilles: beetles were sampled in all four main islands (Cuba, Hispaniola, Puerto Rico and Jamaica) and analyzed using the combination of molecular and morphological data. The genus Phaenonotum contains four single-island endemics, of which those from Cuba, Jamaica and Hispaniola are wingless and form a clade that diversified ca. 46 million years ago (Ma) and likely colonized the Caribbean via the GAARlandia land bridge. In contrast, the Puerto Rican endemic and the two remaining non-endemic species colonized the Greater Antilles by over- water dispersal during the Oligocene-Miocene. The analysis of the genus Crenitulus revealed that Greater Antillean species belong to two separate clades: the Crenitulus yunque clade endemic for Cuba and Hispaniola, and the Crenitulus suturalis clade containing specimens from Greater Antilles and from northern America. A detailed revision of the Crenitulus yunque clade using morphology and molecular-based species delimitation recognized 11 species locally endemic for...
4

Phylogenetic Community Structure Of Aquatic Beetle Assemblages In A Multi-wetland Experiment

Kelly, Sandor Lawrence 01 January 2012 (has links)
Phylogenetic Community Structure (PCS) metrics are becoming more common in community ecology. PCS metrics estimate the phylogenetic relatedness among members of an ecological community or assemblage. If ecological traits are conserved, then phylogenetic clustering (i.e., taxa are more closely related than expected by chance) indicates habitat filtering as the key process in community assembly. On the other hand, a pattern of phylogenetic overdispersion (i.e., taxa are more distantly related than expected by chance) suggests competition is dominant. Most studies to date have used PCS of unmanipulated ecosystems, but the value of PCS metrics will be best revealed in experiments. This project used PCS for aquatic beetle (Coleoptera) assemblages in experimentally manipulated seasonal wetlands on a cattle ranch in south-central Florida, and compared PCS metrics to standard ecological metrics. Wetlands were experimentally treated with all combinations of pasture management, fencing to exclude cattle, and controlled burning during 2006-2009. Beetle assemblages in fenced wetlands were significantly more overdispersed compared to non-fenced wetlands, suggesting that this treatment decreases habitat filtering, causing competition to become the dominant process in community formation. There was also a significant pasture x fence x burn interaction effect, with assemblages in wetlands differing in PCS depending on what combination of the three treatments were applied. Phylogenetic Diversity (PD – a measure of branch length of a community or assemblage on a phylogenetic tree) was highly correlated with genera richness (number of genera), and these metrics along with the expected number of genera (D – an ecological diversity index) found significant differences among burn treatments and a pasture x iii burn interaction. The results of this study indicate that PCS metrics complement classical ecological methods and should be widely applied.

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