Figure 4. Probably non-bioluminescent and probably bioluminescent taxonomic categories over depth.

On the left, taxonomic make-up of the probably non-bioluminescent (including unlikely) observations. On the right, taxonomic components of the probably bioluminescent observations (including likely). The total number of observations differs between the two panels and across depths (see Fig. 2a), but the proportion between 0 and 1 of each group is represented over depth (0 to 3,900 m) using bins of 100 m. Silhouettes are in the public domain, accessible at http://phylopic.org.