Smooth Urn Sponge

Leucilla nuttingi

The smooth urn sponge, Leucilla nuttingi, is a calcareous sponge known for its distinctive urn shape and cream-white color. It features a single osculum at its free end, which is a characteristic opening through which water exits. Typically, these sponges are found in clusters of 5 to 10 individuals, attached to rocks in low intertidal zones. Divers can encounter these sponges in the Eastern Pacific and Arctic regions, ranging from Northern Alaska to Baja California. They thrive in both subtropical and polar climates, inhabiting depths from the surface down to 155 meters. However, most sightings occur at depths shallower than 40 meters, with a significant number found at depths less than 20 meters. The smooth urn sponge is sessile, meaning it remains fixed in one place, and it is part of the filter-feeding community. As a member of the class Calcarea, it is hermaphroditic, with a life cycle that includes a free-swimming larval stage before settling on a substrate to mature into a young sponge. This species has not been evaluated for conservation status by the IUCN, CITES, or CMS, leaving its conservation status officially unassessed. For divers, encountering the smooth urn sponge offers an opportunity to observe the life of marine filter feeders. These sponges are not known to pose any threat to humans, making them a safe and intriguing subject for underwater observation.