Aim: As we enter an era of major biodiversity shifts, understanding large-scale biodiversity patterns has become crucial for ecological and conservation purposes. Often, conservation priorities are based on concepts derived largely from species richness, yet recent work shows that different facets of biodiversity are also crucial for proper ecosystem continuity, function and services. One facet of biodiversity increasingly relevant to conservation is functional diversity. Here, we aim to improve our understanding of large-scale patterns of biodiversity by testing the hypothesis that species richness can also accurately estimate functional diversity along the latitudinal gradient of species richness in fish.Location: Marine environments. Time period: Contemporary.