Fig. 1: Global biogeography of rarity for bony fishes (a–Actinopterygii) and cartilaginous fishes (c–Elasmobranchii) across Coastal Systems.

The functional index used here was distinctiveness (see Supplementary Fig. 1 for workflow and Supplementary Fig. 2 for index details). Plots a and c illustrate the numbers of rare species found in each 2° grid cell (species that are both rare taxonomically and functionally (distinct)). Plots b, d shows the Standardized Effect Sizes (SES), where red shaded cells represent an excess of rare species higher than expected by chance and blue cells represent fewer rare species than expected. For results using functional uniqueness, see Supplementary Fig. 4.