Lamellibrachia luymesi in the Gulf of Mexico - with tubes died blue to measure growth rates

"Close-up photograph of the symbiotic vestimentiferan tubeworm Lamellibrachia luymesi from a cold seep at 550 m depth in the Gulf of Mexico.  The tubes of the worms are stained with a blue chitin stain to determine their growth rates.  Approximately 14 mo of growth is shown by the staining here."  Source: Microfauna–Macrofauna Interaction in the Seafloor: Lessons from the Tubeworm. Boetius A PLoS Biology Vol. 3/3/2005, e102