Mesenterial filaments are string-like extensions of the mesenteries—the internal folds of tissue which create structure within a coral polyp's body. They are typically bright white and full of nematocysts—specialized stinging cells that corals use to capture and kill prey, and to sting their competitors.
Yeah I noticed some receding on one side almost looked cut. Brought the scoly closer to front and on a small piece of rock to stay elevated and long behold a hermit crab comes right to the spot it’s receding.