Phylogeny of Hisonotus Eigenmann & Eigenmann, 1889 (Loricariidae: Hypoptopomatinae)

Author(s)

Fernanda de Oliveira Martins

• Document type: Doctoral Thesis
• Press: São José do Rio Preto. 2016-05-06.
• Institution: Universidade Estadual Paulista (Unesp). Instituto de Biociências Letras e Ciências Exatas. São José do Rio Preto
• Defense date: 2016-04-08
• Advisor: Francisco Langeani

Abstract

The genus Hisonotus was described by Eigenmann & Eigenmann, 1889 and for a long time it was considered a junior synonym of Otocinclus and/or Microlepidogaster. After its revalidation, many new species were described and today, Hisonotus with 31 valid species, is one of the genera with greater number of species within the Hypoptopomatinae. Despite of this, the diagnosis of the genus is inadequate, complicating the description of new species and the recognition of the real diversity of the genus. In addition, there is no consensus on the phylogenetic position of the genus, neither on its monophyly. Based on that, the main aim of the present study was to perform a phylogenetic analysis of Hisonotus species, using morphological characters, in order to test the monophyly of the genus, producing a hypothesis on the phylogenetic relationship of the Hisonotus species, and of them and other species of the Hypoptopomatinae. Also, another aim was to contribute to produce a diagnosis for the genus, based on synapomorphies, as well as to redescribe the type species H. notatus and describe possible new species for the genus, contributing to the understanding of the diversity of the group. The phylogenetic study was performed using 123 morphological characters observed on 104 terminal taxa, including members of the Astroblepidae, Lithogeninae, Delturinae, Loricariinae, Hypostominae, and of all valid genera of the Neoplecostominae and the Hypoptopomatinae, among them 29 species of the Hisonotus. The analysis produced 16 equally parsimonious trees, from which a consensus cladogram was built. As expected, the results indicate Hisonotus as a non-monophyletic group. Here, Hisonotus sensu strictu is delimited and its position within the subfamily, the internal relationships and its differentiation from Otothyropsis are discussed. Comments on general aspects on phylogenetic relationships of the Hypoptopomatinae and evolution of the group are made. (AU)

• FAPESP's process: 11/21728-7 - Phylogeny of Hisonotus Eigenmann & Eigenmann, 1889 (Loricariidae: Hypoptopomatinae)
• Grantee: Fernanda de Oliveira Martins
• Support Opportunities: Scholarships in Brazil - Doctorate