Sponges host a wide range of cryptic biodiversity both internally and externally. This study quantified the biodiversity inhabiting, or associated with, three morphologically distinct coral reef sponges. Coelocarteria singaporensis , Coscinoderma mathewsi and Ircinia microconulosa were collected from fringing reefs at Orpheus Island, central Great Barrier Reef, across monsoonal seasons (wet and dry) and diurnal periods (mornin...