Amazonization: expansion of the occurrence and dominance of non-native Amazonian fish in freshwater ecosystems

• Grant number: 24/20950-8
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: July 01, 2025
• End date: June 30, 2028
• Field of knowledge: Biological Sciences - Ecology - Ecosystems Ecology
• Principal Investigator: Lilian Casatti
• Grantee: Aymar Orlandi Neto
• Host Institution: Instituto de Biociências, Letras e Ciências Exatas (IBILCE). Universidade Estadual Paulista (UNESP). Campus de São José do Rio Preto. São José do Rio Preto , SP, Brazil

Abstract

Biological invasion is a process by which a non-native species is transported, introduced and establishes itself in a new area, generating impacts on the site. This process causes the loss of native species and alters ecosystem services, reflecting on the quality of human well-being in the area. Amazonian fish are exploited internationally for the aquarium trade, sport fishing and aquaculture, resulting in the introduction of species such as tucunarés, corvina and pirarucu in regions outside the Amazon or even the Neotropics. Several regions have already demonstrated vulnerability to invasions of species tolerant to warmer waters, intensified by global warming. Thus, this project aims to investigate the distribution of Amazonian fish species outside their natural range on global, regional and local scales, focusing on the number of occurrences, species richness and proportion in relation to native species, and to indicate the possible effects on local ecosystem services. Using global data and long-term monitoring of reservoirs in the Paraná River Basin, the project will apply statistical models with the aim of: (1) identifying global patterns of occurrence and species richness of Amazonian fish species outside their natural range; and (2) assessing changes in the fish fauna over time in the Paraná River Basin and its reservoirs, considering the richness and proportion of Amazonian species. With the international demand for Amazonian fish combined with climate change and habitat modifications in several basins, an increase in the global distribution and richness and proportion of Amazonian fish is expected. This phenomenon is expected to occur on a global scale, particularly in tropical and tropicaltemperate transition zones.