Full text
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| Author(s): |
Henrique Rosa Varella
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: | 2016-02-29 |
| Examining board members: |
Naercio Aquino Menezes;
Maria Isabel Pinto Ferreira Landim;
Mônica de Toledo Piza Ragazzo;
Alessio Datovo da Silva
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| Advisor: | Naercio Aquino Menezes |
| Abstract | |
Ninety valid species of Crenicichla and eight of Teleocichla are currently recognized. Together, the target-genera of this study represent almost 1/5 of the diversity of Cichlinae, a Neotropical subfamily of Cichlidae. Although the species of Crenicichla and Teleocichla are part of a monophyletic group, corroborated by phylogenies based on both morphological and molecular data, the relationships among the species included are not well-established. The two previous phylogenetic studies partially disagree with each other and included only part of the diversity of the group. Based only on molecular data, these studies were not supported by a morphological study that would indicate synapomorphies or diagnostic characters for the identification of the monophyletic groups proposed. The primary objectives of the present study are to test the monophyly of the group formed by the species of Crenicichla and Teleocichla and to identify and define monophyletic unities within this group using morphological characters. As a secondary objective, this study also aims to test the recent hypotheses of phylogenetic relationships between the species of Crenicichla and Teleocichla and the remaining Neotropical cichlids. All the valid species of Teleocichla and 54 species of Crenicichla (60% of the valid species) were included, as well as one new species of Teleocichla and five new species of Crenicichla. Twenty representatives of different lineages of Cichlinae were also included, resulting in a total of 88 terminal taxa. Cladistic analyses were performed on a matrix of 211 characters derived from a comparative study of external morphology, including color patterns, and osteology. Besides the equal-weighting analysis, other analyses using different weighting systems were explored, such as successive weighting and implied weighting using different values of the variant k. After comparison and discussion of the results obtained by the different analyses, the topology obtained by the analysis with implied weighting using k=3 was chosen as the base for phylogenetic inferences. Two alternative classifications were discussed and the one based on the choice of subgenera instead of genera to represent the monophyletic groups found was preferred to minimize nomenclatural changes, especially because the position of Crenicichla macrophthalma (type-species of Crenicichla) is still considered instable. The genus Crenicichla is corroborated as a monophyletic group formed by all species of Crenicichla and Teleocichla included, and is supported by 40 synapomorphies. Within the genus, a complex scenario is found with many lineages, as also pointed out in previous studies. However, the relationships between these lineages are instable, being variable according to the different weighting systems used and partially in disagreement with respect to previous studies. Teleocichla is a monophyletic group within Crenicichla and is, consequently, considered one of the eight subgenera of Crenicichla. The subgenus Crenicichla is represented only by C. macrophthalma. The remaining six subgenera (Wallaciia, Batrachops, Hemeraia, Saxatilia, Lugubria and Lacustria) correspond totally or partially to species groups previously proposed for Crenicichla. Within Lacustria, four species complexes were delimited: C. missioneira, C. scottii, C. jaguarensis and C. lacustris sensu stricto. Nominal species of each subgenus were listed and diagnoses for their identification were performed. A new hypothesis of relationships between Crenicichla and Cichlinae is inferred based on the results of the analysis, in which Crenicichla is sister-group to the clade formed by Chaetobranchus flavescens and all the representatives of Cichlasomatini and Geophagini included (AU) | |
| FAPESP's process: | 11/14630-0 - Phylogenetic relationships of the species of Crenicichla and Teleocichla (Teleostei: Cichlidae) |
| Grantee: | Henrique Rosa Varella |
| Support Opportunities: | Scholarships in Brazil - Doctorate |