Systematic of genus Ochmacanthus: a group of neotropical scale-eatings catfish (Teleostei: Siluriformes: Trichomycteridae)

• Grant number: 12/16750-6
• Support type: Scholarships in Brazil - Master
• Effective date (Start): December 01, 2012
• Effective date (End): April 30, 2014
• Field of knowledge: Biological Sciences - Zoology
• Principal researcher: Mario Cesar Cardoso de Pinna
• Grantee: Caio Santos Neto
• Home Institution: Museu de Zoologia (MZ). Universidade de São Paulo (USP). São Paulo , SP, Brazil

Abstract

This project proposes a detailed taxonomic study on the genus of catfish that eats scales Ochmacanthus. The taxon is part of the neotropical fish popularly known as candirus, of particular evolutionary relevance, behavioral and ecological, but still little known in all aspects of their systematics and biology. The Ochmacanthus genus currently contains five species considered valid. However, the latest revision occurred almost 100 years ago, and is widely recognized that the taxonomy of the genus is severely deficient. The delimitation of species and diagnoses are unsatisfactory, making identifications uncertain or impossible. This is particularly conspicuous in view of the abundance of the genus and its apparent ecological importance in many neotropical habitats. So, initially, the job will conduct an assessment of the number and delimitation of species of Ochmacanthus. This part of the study will be a formal taxonomic revision, which will include synonymies, diagnoses, descriptions and geographical distributions of all species recognized as valid in the study. The vast material collected over the past few decades and now available for study in Brazilian collections forms an especially proper basis for the proposed study. Furthermore, a phylogenetic analysis will be performed that will test the monophyly of Ochmacanthus and determine its phylogenetic position among Stegophilinae, subfamily which belongs to genus. The data for both, the review and for phylogenetic analysis, will be obtained from external morphology (including morphometry), pigmentation pattern and internal anatomy (particularly osteology), which will be combined with data previously proposed. The results will be relevant for assessing the biodiversity and evolution of a component relatively small but important neotropical ichthyofauna. (AU)