Age-estimation of the Christmas Tree Worm Spirobranchus giganteus (Pomlychaeta, Serpulidae) Living Buried in the Coral Skeleton from the Coral-growth Band of the Host Coral

The tubicolous polychaete, Spirobranchus giganteus lives buried in coral skeletons. Its age and longevity were estimated indirectly from the annual coral-growth rings of the host coral counted on soft X-rays radiographs. Since the polychaete tube grows 0.2 to 1mm per year in orifice diameter, some had lived more than 10 years, and a few had lived more than 40 years. The application of soft X-rays for age determination of coral associated polychaete is useful for determining the correct age.