Data from: Fish assemblage convergence along stream environmental gradients: an intercontinental analysis

Species that pass through similar environmental filters, regardless of
geographic proximity or evolutionary history, are expected to share many
traits, resulting in similar assemblage trait distributions. Convergence
of assemblage trait distributions among different biotic regions would
indicate that consistent ecological processes produce repeated patterns of
adaptive evolution. This study analyzes trait-environment relationships
across multiple stream fish assemblages representing evolutionarily
divergent faunas. We hypothesized that trait-environment patterns converge
across regional faunas in response to a common set of environmental
filters acting on functional traits. One hundred and ninety-seven species
and forty streams were sampled from five regions: Belize, Benin, Brazil,
Cambodia, and United States of America. By examining trait-environment
plots, multiple congruent trait-environment patterns were found across all
regions, indicative of a consistent set of environmental filters acting on
local community assembly. The consistency of these patterns strongly
suggests that water velocity and habitat structural complexity function as
universal environmental filters, producing similar assemblage trait
distributions in streams across all regions. Bivariate relationships were
not universal, and only one of the associations between a single
functional trait and single environmental variable was statistically
significant across all five regions. Strong phylogenetic signal was found
in traits and habitat use, which implies that niche conservatism also
influenced assemblage trait distributions. Overall, results support the
idea that habitat templates structure trait distributions of stream fish
assemblages and do so in a consistent manner.