User:Muffin110/citing sources

Diogenes heteropsammicola is a species of hermit crab that lives within "walking corals" of the genera Heterocyathus and Heteropsammia.

http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0184311

These coral have an internal cavity that is typically occupied by a symbiotic sipunculan worm; in the crab's habitat in the Ōshima Straight south of Amami Ōshima, it is often found inside the corals instead.