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| Author(s): |
Elisandra de Almeida Chiquito
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Piracicaba. |
| Institution: | Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC) |
| Defense date: | 2010-12-03 |
| Examining board members: |
Alexandre Reis Percequillo;
Ulyses Francisco Jose Pardiñas;
Marcelo Weksler
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| Advisor: | Alexandre Reis Percequillo |
| Abstract | |
Taxonomic and systematic studies have often used more than one tool to recover information on biodiversity, but also on the biogeography and evolutionary history. Commonly, morphological and molecular approaches are used together, sometimes corroborating each other, resulting in the recognition of new Oryzomyini taxa, including supraespecifics level, throughout phylogenetic patterns. Sooretamys angouya exhibits a wide geographic distribution and occupy a large range of habitats, which suggests the possibility of some degree of intraspecific variation, which makes the species an excellent model for geographic variation and phylogeographic studies. The goal of this study was to analyze qualitatively and quantitatively the samples of S. angouya throughout its distribution, and to evaluate the existence of variation in morphological and molecular level. I pooled nearby localities and / or those localities included in a single geographic in order to increase the sample size. The morphological and morphometric analysis were conducted on adults males and females, according to the patterns of molar wear. The morphometric characters employed were five external body measurement from museum labels and 18 cranial and tooth measurements. The univariate and multivariate normality of data were tested using the Kolmogorov-Smirnov and Mardia\'s kurtosis tests, respectively. The analysis of geographic variation was based on Dice-Leraas diagrams and Discriminant Analysis. The qualitative analysis of morphology was based on characters of pelage and skull-dental. Molecular analysis was conducted with a fragment of 675 bp of mitochondrial cytochrome b gene of 48 individuals. The trees were constructed by the methods of Maximum Likelihood, Maximum Parsimony and Neighbour-Joining. It has also conducted a network analysis of haplotypes and calculated basic statistics. The geographical distribution of S. angouya is limited by the localities Conceição do Mato Dentro, Minas Gerais, north, Arroyo Grande, RS, south, Venda Nova, ES, east and Isla El Chapetón, Rio Parana in Entre Rios, Argentina, covering the entire coastal region of Espírito Santo to Rio Grande do Sul and into the interior. Morphometric analysis showed that there is a slight reduction in mean body length and head north to the south and steeper in the eastwest. However, the sample from Paraguay, the westernmost collection localities, exhibit long and robust skulls, apparently larger than the sample Boracéia- Casa Grande, SP. Qualitatively, dental and cranial features exhibited no tangible variation linked to geography, although they vary within species. We obtained an alignment of 675 bp of Cyt b from 48 individuals of S. angouya from ES, RJ, SC, Brazil and Paraguay. The four molecular analysis of variance conducted have not shown a clear geographic structure of haplotypes, except for one subclade supported by high bootstrap values which are contained only four haplotypes Paraguayans, the region\'s river basin Tebicuary. It was concluded that there is geographic variation in S. angouya and that this may have been generated by recent events. (AU) | |
| FAPESP's process: | 07/05859-9 - Geographic variation and phylogeography in Sooretamys angouya (Fischer, 1814) (Cricetidae: Sigmodontinae) |
| Grantee: | Elisandra de Almeida Chiquito |
| Support Opportunities: | Scholarships in Brazil - Master |