Sea cucumbers are deep sea-dwelling animals that owe their shape to endoskeletons below the skin. These endoskeletons have the peculiar property of being liquefacient; when a sea cucumber is in danger, it can essentially liquefy itself and slip through minuscule spaces, then re-harden when safe from harm’s way. Its transmutable nature presents a special challenge in containing it within aquariums that have large pumps or filtration systems.
Liquefacient (pronounced “lik-wih-FAY-shent”)
1. a substance that liquefies or causes liquefaction
2. *becoming or causing to become liquid
From Latin liquere, “be fluid”, plus facere, “to make”.