Full text
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| Author(s): |
Carine Cavalcante Chamon
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | São Paulo. |
| Institution: | Universidade de São Paulo (USP). Instituto de Biociências (IBIOC/SB) |
| Defense date: | 2012-02-10 |
| Examining board members: |
Mario Cesar Cardoso de Pinna;
Heraldo Antonio Britski;
Marcelo Ribeiro de Britto;
Naercio Aquino Menezes
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| Advisor: | Mario Cesar Cardoso de Pinna |
| Abstract | |
The Acanthicus group (Siluriformes, Loricariidae) is currently composed of four genera: Acanthicus, Megalancistrus, Leporacanthicus e Pseudacanthicus. The monophyly of the group has been previously supported by both morphological and molecular data. To investigate the relationships among the Acanthicus group species, 21 taxa of the ingroup and 12 taxa of other Ancistrini as out-groups were studied on the basis of 121 phenotipic characters of different anatomical complexes. Parsimony analysis resulted in two most parsimonious trees with 453 steps (CI= 0,32 RI= 0,66). Monophyly of the Acanthicus group was corroborated by 11 synapomorphies, three of which exclusive: hiomandibular ridge contiguous with ridge of the quadrate, distal edge of premaxillary teeth strongly curved with well-developed keels. Relationships of the Acanthicus group plus Spectracanthicus resulted in the following topology: (Spectracanthicus ((Megalancistrus, Acanthicus) (Leporacanthicus, Pseudacanthicus))). Genus-level nomenclature of the group was reformed on the basis of the phylogenetic hypothesis and of a taxonomic revision which resulted in the recognition of 18 valid species in the Acanthicus group, nine of which new. In the genus Pseudacanthicus, P. fordii was recognized as a junior synonym of P. serratus and P. histrix of P. spinosus, with six new species from the Aripuanã, Tocantins, Tapajós, Curuá-Una and Xingu Rivers Basins. Oligancistrus was recognized as a junior synonym of Spectracanthicus and three new species were described in the latter, from the Tapajós, Tocantins and Xingu River Basins. (AU) | |
| FAPESP's process: | 07/07770-5 - Taxonomic review and phylogenetic relationships of the Acanthicus group (Siluriformes, Loriicariidae) |
| Grantee: | Carine Cavalcante Chamon |
| Support Opportunities: | Scholarships in Brazil - Doctorate |