APPLICATION OF DNA BARCODING IN THE IDENTIFICATION OF ICHTHYOPLANKTON FROM A SECTION OF THE PARDO RIVER, UPPER PARANÁ BASIN

• Grant number: 24/22855-2
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: July 01, 2025
• End date: December 31, 2025
• Field of knowledge: Biological Sciences - Genetics - Animal Genetics
• Principal Investigator: Fábio Porto-Foresti
• Grantee: Luisa Alves da Silva
• Host Institution: Faculdade de Ciências (FC). Universidade Estadual Paulista (UNESP). Campus de Bauru. Bauru , SP, Brazil

Abstract

The Neotropical region extends from southern Mexico to Argentina, encompassing various important basins for Brazilian hydrography, such as the Upper Paraná basin. This region is home to the most diverse ichthyofauna on the planet, with approximately 9,100 species, highlighting the two largest orders (Siluriformes and Characiformes). This great species diversity is reflected in the Pardo River, one of the main waterways of the Upper Paraná basin. The Pardo River is a major tributary of the Grande River and one of the largest rivers in São Paulo state, crossing 15 municipalities. The region of Serrana, supplied by the Pardo River, houses the Pedra plant, which, 20 years ago, was the site of an environmental disaster caused by the accidental release of sugarcane molasses, resulting in the death of tons of fish. Thus, the need for conservation programs focused on the fish population of the Pardo River becomes evident, given the lack of information about the impact of such events on the local ichthyofauna. This study aims, through DNA barcoding techniques, to monitor the ichthyofauna by evaluating the density of ichthyoplankton collected from the Pardo River and identifying the species that use this section for reproduction. Ichthyoplankton collections will be carried out during the reproductive cycles of 2024 and 2025. The material will be collected using a cylindrical-conical net with a flowmeter attached to its mouth to calculate density. Subsequently, the eggs and larvae will be separated from the substrate using a stereoscopic microscope. For DNA extraction, a Transgen column kit will be used, following the manufacturer's instructions. PCR will then be performed using the COI gene, and the PCR product will be sequenced with the BigDye Terminator v3.1 kit. Finally, the sampled species will be identified using the BOLD Systems platform, enabling analyses of ichthyoplankton migration behavior and origin, as well as comparisons between two reproductive cycles. This is of utmost importance for the conservation of the species in this river.