Unraveling the diversity and origins of the genus Characidium (Characiformes: Crenuchidae) in the Neotropical region: a study of Systematics and Biogeography with a genomic and integrative approach

• Grant number: 23/09871-6
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Effective date (Start): January 01, 2024
• Effective date (End): December 31, 2025
• Field of knowledge: Biological Sciences - Zoology - Taxonomy of Recent Groups
• Principal Investigator: Claudio de Oliveira
• Grantee: Leonardo Oliveira Silva
• Host Institution: Instituto de Biociências (IBB). Universidade Estadual Paulista (UNESP). Campus de Botucatu. Botucatu , SP, Brazil
• Associated research grant: 20/13433-6 - Phylogeny and molecular identification of fishes of the superorder Ostariophysi (Chordata: Actinopterygii) using genomic approaches, AP.TEM

Abstract

Characidium, a genus of freshwater fish endemic to the Neotropical region, is the most representative of the family Crenuchidae, with 85 species. In 1993, a morphological phylogenetic analysis included 18 species and indicated the genus as monophyletic. Since then, 46 new species have been described, but most have never been included in a phylogenetic study. In 2011, a molecular study raised doubts about the monophyly of the genus, but it has not been confirmed to date. There is also a scarcity of studies on the evolutionary history and the processes that led to the current distribution of the genus in South America. The total richness of the genus is still unknown, as most specimens in scientific collections are only identified at the genus level. Problems with species delimitation within the genus are reported in the literature, where the use of solely morphological approaches does not result in a conclusive definition of the taxonomic and geographic limits of several species. Integrative studies combining morphological and molecular data are needed to delimit taxonomically problematic Characidium species and describe new species. The proposed postdoctoral project aims to address and solve the phylogenetic, biogeographic, and most of the taxonomic open questions involving Characidium using genomic data (UCEs) and molecular data from Sanger sequencing integrated with morphological data. The results will be important for understanding the evolution and taxonomy of the genus, assisting in the knowledge of Brazilian biodiversity and species conservation.