"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."
One of the more common and often more disturbing observations for many newer reef hobbyists is seeing their corals extend their mesenterial filaments. Reactions