Hexactinellida from the Perth Canyon, Eastern Indian Ocean, with descriptions of five new species.

Glass sponges (Class Hexactinellida) are described from the Perth Canyon in the eastern Indian Ocean, resulting in 10 genera being recorded, including 11 species, five of which are new to science. In addition, the study resulted in two new records for Australia, Pheronema raphanus and Monorhaphis chuni, and one new record for the Indian Ocean, Walteria flemmingi. A second species of Calyptorete is described over 90 years after the genus was first established with a single species. A significant difference was noted between the condition of sponges collected on the RV Falkor, which used an ROV, and the earlier RV Southern Surveyor expedition, which used sleds and trawls. The ROV collected specimens were in excellent condition, while those from the sleds and trawls tended to be damaged or fragmented.