The Neotropical freshwater fish (NFF) fauna represents the most diverse group of continental vertebrates, boasting over 6,345 species found throughout South America, Central America, and the Greater Antilles.

To consolidate previously scattered information on ecological preferences and tolerances, a comprehensive dataset of ecological traits, or ecotraits, for NFF species has been created.

This extensive ecomatrix is the culmination of over five years of meticulous data compilation, drawing on both published research and the expertise of 55 ichthyologists.

The final dataset comprises 266,490 observations and encompasses 6,342 NFF species, making it accessible to the scientific community for further research.

Included in the dataset are adult modal values for 42 ecotraits, which cover critical aspects such as body size, habitat utilization in relation to water chemistry, physical habitat structure, dietary classifications, and behavioral traits.

While biodiversity assessments typically emphasize species counts, understanding functional traits is essential for grasping community dynamics and addressing biodiversity loss.

The NFF ecomatrix serves as a foundational resource for future ecological and conservation studies focused on Neotropical aquatic biodiversity.

Despite the richness of this dataset, there are still significant gaps in life history and ecological trait data for many NFF species, which poses challenges for achieving a comprehensive ecological understanding.