Full text
| |
| Author(s): |
Axell Kou Minowa
Total Authors: 1
|
| Document type: | Master's Dissertation |
| Press: | Campinas, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Instituto de Biologia |
| Defense date: | 2021-03-04 |
| Examining board members: |
André Rinaldo Senna Garraffoni;
Silvio Shigueo Nihei;
André Victor Lucci Freitas
|
| Advisor: | André Rinaldo Senna Garraffoni |
| Abstract | |
Among the least known metazoa, we can easily highlight the phylum Gastrotricha, a group of acoelomate aquatic microinvertebrates found in practically all aquatic environments of the world, dulcolous or marine. As an exception to the benthic majority of the phylum, some animals present several modifications that allow the semiplanktonic lifestyle in the freshwater periphyton, between roots of aquatic plants. Although its representatives have been known for more than a century, little is known about its evolution, ecology and geographical distribution. Except for the hypothesis of the single origin of the semiplanktonic lineage from a benthic ancestor, the evolutionary relationships are still controversial, with conflicting phylogenetic results regarding the origin of families and their subgroups. In this context, the present work uses an integrative taxonomy to — besides accessing biodiversity — elucidate the evolutionary history of the taxon under a total evidence approach, with different data sources, both morphological and molecular. Two new species for science are presented, using modern morphology techniques, such as differential contrast interference lenses (DIC) and scanning electron microscopy (SEM) that allow the study of morphological characters previously inaccessible. In addition to new records of already known species, expanding the knowledge of the geographic distribution of these organisms. Furthermore, the results of endemicity analysis and topographic units performed with meiofaunal species of the Atlantic Forest in order to understand the distribution patterns of these organisms presents discrepant patterns of macrofaunal organisms, such as arthropods and vertebrates. The phylogenetic analysis of total evidence supported the hypothesis of a single benthic ancestor, besides the monophyly of the two main semiplanktonic lineages and their non-monotypic subgroups, giving phylogenetic support to the current taxonomic classification. (AU) | |
| FAPESP's process: | 19/01955-0 - Rethinking the classification of the Dasydytidae family (Chaetonotida: Gastrotricha): integrative taxonomy, tree thinking and total evidence |
| Grantee: | Axell Kou Minowa |
| Support Opportunities: | Scholarships in Brazil - Master |