Sea Dwelling Creatures has just recently released an article and pictures of a very rare coral called the Heteropsammia coclea. Like similar LPS corals from the family Fungiidae, it doesn’t attach itself to a rocky surface. Instead, it likes to dwell in the sand. But what
really makes this coral unique is that it lives on top of a sipunculid worm, also called a peanut worm.
While the coral is still in larval form, it attaches to the back of a peanut worm. As it grows, it envelops the worm and nearly engulfs in entirely. The worm takes up residence in the base of the coral, carving out a small hole from which it can gather food and move around. This is advantageous to the coral as the worm can prevent the coral from becoming buried in sand. The movement of the coral is achieved by the worm extending and retracting its feeding apparatus, which also helps keep the hole in the bottom of the coral open. The worm benefits from constantly
having a protective shell around it, while the coral gains mobility and a method of getting out of the sand if buried.
Sea Dwelling Creatures goes on to say that they will be donating many of their specimen to a public aquariums and scientists for study, but that a few of them will make it to the hobbyist. This is a very noble stance in my opinion, since the company is not only aiding the scientific community, potentially losing revenue in the process.