Tethya fastigata

Tethya fastigata is a type of sponge belonging to the family Tethyidae. It is found in the temperate waters of the Southwest Pacific, particularly around New Zealand. These sponges are sessile, meaning they remain attached to a substrate rather than moving freely. They are typically located in environments such as rocky reefs, where they can anchor themselves securely. Divers may encounter these sponges at various depths, with records indicating they are commonly found at depths shallower than 40 meters, and occasionally deeper, up to about 90 meters. The life cycle of Tethya fastigata involves a free-swimming larval stage known as the parenchymella. This stage allows the sponge to disperse before settling down on a suitable substrate, where it matures into a sessile adult. As members of the Demospongiae class, they are hermaphroditic, possessing both male and female reproductive organs. While diving, encountering Tethya fastigata can be an interesting experience due to their unique sponge-like appearance. They pose no threat to humans and are considered harmless. Currently, there is no evaluation of their conservation status by the IUCN, and they are not listed under CITES or CMS.