Stress-induced butt-vomiting might sound comical, but it serves a useful purpose – the eviscerated organs of some sea cucumbers (like the black sea cucumber, Holothuria leucospilota) can entangle and neutralize predators.

“[S]timulus-selective response in H. leucospilota may be turned on only when an encroaching predator exerts a sufficiently large physical force directly onto the Cuvierian organ,” the researchers explain.

(Roberto Pillon/World Register of Marine Species/CC BY-NC-SA)