Taxonomic inventory of the sponges (Porifera) of the Mariana Islands

Abstract—We review the sponge fauna of the Mariana Islands based on new and existing collections, and literature records. 124 species of siliceous sponges (Class Demospongiae) and 4 species of calcareous sponges (Class Calcarea) have been identified to date, representing 73 genera, 44 families, within 16 orders. Several species are adventive. Approximately 30% (40) of the species encountered are undescribed, but not all are endemics, as the authors know them from other locations. Approximately 30% (38) of the species are known from diverse locations within the Indo West Pacific, but several well-known, widespread species are absent. The actual diversity of sponge fauna of the Marianas is considerably higher, as many species, especially cryptic and encrusting taxa, remain to be collected and studied.