Numbers of sponge species recorded in each of 232 marine ecoregions of the world extracted from the World Porifera Database (available: www.marinespecies.org/porifera, accessed 2011 Aug 31). The type localities and additional confirmed occurrences in neighboring areas of almost all ‘accepted species’ were entered in one or more of the Marine Ecoregions of the World, but many non-original distribution records in the literature are still to be evaluated and entered. Moreover, many sponge taxa are recorded in the literature undetermined and these are not included in the WPD. Thus, the data presented here are to be considered a conservative or ‘minimal’ estimate of the actual distributional data.