Kuphus

Kuphus is a genus of shipworms, marine bivalve molluscs in the family Teredinidae. While there are four extinct species in the genus, the only extant species is Kuphus polythalamius (also incorrectly spelled as Kuphus polythalamia). It is the longest bivalve mollusc in the world, where the only known permanent natural habitat is Kalamansig, Sultan Kudarat in the Philippines.

Members of this genus secrete calcareous tubes. Based only on the calcareous tube, this species was originally thought by Linnaeus to be a tube worm, so he placed it in the genus Serpula. Despite the fact that Kuphus polythalamius is now known to be a mollusc, its common name is the giant tube worm. Since 1981 however, the name "giant tube worm" has also been applied to the hydrothermal vent species Riftia pachyptila, which is indeed a worm, an annelid.