Sistemática e evolução de aranhas-armadeiras (CTENIDAE: PHONEUTRIA) a partir de evidências moleculares, morfológicas e ecológicas

• Ano de defesa: 2012
• Autor(a) principal: Guilherme Henrique Fernandes Azevedo
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; Brasil; ICB - INSTITUTO DE CIÊNCIAS BIOLOGICAS; Programa de Pós-Graduação em Ecologia, Conservacao e Manejo da Vida Silvestre; UFMG
• Palavras-chave em Português: Phoneutria; Morfometria geométrica; Aranhas-armadeiras; Ecologia; Aranhas/anatomia & histologia
• Link de acesso: http://hdl.handle.net/1843/43309

The spider genus Phoneutria currently comprises eight Neotropical species whose taxonomic history is controversial, especially regarding four species from the Atlantic Forest and the Cerrado. Since the species of Phoneutria are widely distributed along the major biomes of South America, but still with endemism of some species, these organisms are potential models for phylogeographic studies. Many of the hypotheses proposed to explain the Neotropical diversity involve the participation of environmental factors. However, few studies address the role of the niche in the process of diversification of lineages. In this paper, we use molecular, morphological and ecological evidence to delimit species within the genus and propose hypotheses about the environmental factors and possible historical events involved in the diversification of lineages of Phoneutria. Geometric morphometric analysis indicates that the shape of male genitalia can be used to differentiate three of the four species whose taxonomy is controversial. The shape of female genitalia, in turn, has no clear differences between species, and a mitochondrial gene tree based on COI does not recover any of these four species as monophyletic. Coalescence analysis indicates the existence of three independent evolutionary lineages, which correspond to the three groups found based on the morphology of male genitalia. The results indicate, therefore, the existence of seven entities that could be considered as species in this genus, to which the following names can be applied: Phoneutria fera, P. nigriventer, P. reidyi, P. boliviensis, P. pertyi and P. keyserlingi. Aspects of the morphology and a hypothesis of phylogenetic relationships among those species are discussed. To study the evolution of the niche, we used a used a Bayesian approach to reconstruct a phylogeny with divergence dates inferred through a relaxed molecular clock model, and environmental data of existent species to reconstruct the ancestral niche on each node. The results show that, in general, the ecological differences occurred in the early diversification of the group, while more recent divergences have shown niche conservatism. The possible events involved in the diversification of Phoneutria are discussed based on the main hypotheses proposed to explain the Neotropical diversity and taking into account the evolution of the niche, geographical distribution and the date of divergence of species.