Neptune’s Cup Sponge (Cliona patera) is a marine sponge belonging to the family Clionaidae, distinguished by its characteristic cup-shaped structure and potentially exceptional size. First described in the nineteenth century, the species was extensively collected for natural history collections, contributing to its increasing rarity. Following the last recorded observation of a living specimen in 1908, new specimens were discovered in the waters off Singapore in 2011. This rediscovery made it possible to investigate the species’ growth and develop conservation strategies. The specimen held at the Museo Civico di Storia Naturale “Giacomo Doria”, registered under inventory number 985, is recorded as originating from Singapore in 1913 and is displayed on the first floor, in the Invertebrates Room.