Open Access

Nisit Ruengsawang, Narumon Sangpradub, Taksin Artchawakom, Roberto Pronzato, Renata Manconi

• Umborotula bogorensis (Weber, 1890) is a freshwater sponge species that is recorded occasionally, mainly on islands and peninsulas of Australasia. Less than 10 records with morphological descriptions and illustrations have been published so far, and the most recent record is dated 1978. A list of the few voucher specimens from museum collections is provided here together with the rich unpublished Sasaki collection from Japan, Korea, and Taiwan, recently deposited in a Japanese museum. The present new record from Northeast Thailand enlarges the geographic range of U. bogorensis to the Indochina mainland. A comparison of historical data vs present Thai records is performed by morpho-analysis(SEM) as well as biogeographic, ecological and climatic data. Results show low variability in shape and size of the diagnostic morphotraits in populations scattered over the wide geographic range. Here we also formally accept the new taxonomic status (rank elevation) of the previous suborder Spongillina as a new order Spongillida. The presence of this potentially threatened species in the Sakaerat Biosphere Reserve, together with its possible long-term persistence in the Bogor Botanical Garden, may support its conservation. Only a census of the known, extremely scattered populations will define the status of this species.