Data for: Substantial intraspecific trait variation across a hydrological gradient in northern Australian fishes

Trait-based models of ecological communities and ecosystem functioning often fail to account for intraspecific variation in functional traits, assuming that intraspecific variability is negligible compared to interspecific variability. However, this assumption remains poorly tested across vertebrate animals where past studies routinely describe species according to mean trait values without explicit consideration of individual trait variability. We assessed nine functional traits for 4,254 individuals belonging to 15 freshwater fish species from 11 families in Northern Australia, including: body elongation, body shape, caudal peduncle throttle, eye size, eye position, gape shape, gape size, mouth position and pectoral fin length. We quantified the extent and geography of intraspecific trait variability and its relationship with riverine hydrologic regimes using a structured sampling design. Using a combination of single- and multi-trait analyses, we demonstrate that intraspecific trait ...