Carnivorous sponges (Porifera, Cladorhizidae) from the Southwest Indian Ocean Ridge seamounts

Our results show that the cladorhizid fauna of the Southwestern Indian Ocean is diverse and seems to be bathymetrically structured with no observed overlap between the newly reported upper bathyal species (~1000 m) and previously described lower bathyal and abyssal species from the area. While the upper bathyal SWIOR species are unique and represent a regionally endemic cladorhizid fauna, similarities in morphology and spicule characters as well as molecular evidence suggests biogeographical affinities to species from the SW Pacific and SW Atlantic, but no similarities to previously reported Antarctic fauna were found. A table of cladorhizid species from the Southwest Indian Ocean and neighboring areas is provided.