Ecological drivers shaping fish species diversity in extreme environments

• Grant number: 25/13976-3
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: February 26, 2026
• End date: August 25, 2026
• Field of knowledge: Biological Sciences - Ecology - Applied Ecology
• Principal Investigator: Rafael Mendonça Duarte
• Grantee: João Henrique Alliprandini da Costa
• Supervisor: Juan Carvajal-Quintero
• Host Institution: Instituto de Biociências (IB-CLP). Universidade Estadual Paulista (UNESP). Campus Experimental do Litoral Paulista. São Vicente , SP, Brazil
• Institution abroad: Dalhousie University, Canada
• Associated to the scholarship: 23/14344-5 - Beneath the pond: unraveling the fish community composition and traits configuration seasonally in natural and artificial temporary habitats of the Atlantic Forest, BP.DR

Abstract

Climate change is driving environments to extremes, forcing species to either shift their distributions, tolerate performance declines, or to cope to novel conditions. While the ecological consequences of species redistribution are increasingly documented, far less is known about how species that remain assemble and coexist under these extreme conditions. Thus, understanding the drives of species diversity in extreme environments is critical to anticipating how biodiversity will reorganize under future climatic scenarios. In this study, we use extreme freshwater environments as natural laboratories to investigate the mechanisms shaping species richness under stressful abiotic conditions and frequent disturbances. Specifically, we will analyse fish assemblages from tropical temporary pools located in a blackwater basin from the coastal plain of Atlantic Forest in southeastern Brazil, integrating multiple ecological and biogeographical frameworks (e.g., island biogeography, environmental filtering, competitive exclusion, trait plasticity). We will evaluate the effects of both extrinsic factors (e.g., spatial isolation, habitat area, environmental disturbance) and intrinsic species-level traits (e.g., dispersal capacity, trait similarity) on species richness patterns. By combining fine-scale community data with individual-level morphological and tolerance traits, this study aims to disentangle the relative contribution of geographic, environmental, and trait-based mechanisms in structuring species richness under extreme conditions, offering insights into how climate-sensitive communities may reorganize in the face of accelerating global change.