The tube of Kuphus polythalamius is known as a crypt and is a calcareous secretion designed to enable the animal to live in its preferred habitat, the mud of mangrove swamps.

A specimen owned by Victor Dan in the United States has a length of 1,532 mm (60 in), which is considerably longer than the largest giant clam.

[6] Marine biologist Ruth Turner studied shipworms and considered that their common ancestor would have been very like Kuphus polythalamius, the most primitive of the teredinids.

[1] In April 2017, the species became the focus of international attention when the announcement of a scientific study conducted in the Philippines was misinterpreted by foreign news reporters as the discovery of a rare live specimen.

While other shipworms feed on submerged wood, K. polythalamius was found to use bacteria in its gills to use hydrogen sulphide in the water as an energy source used to convert carbon dioxide into nutrients.