Cuvierian tubules are clusters of fine tubes located at the base of the respiratory tree in some sea cucumbers in the genera Bohadschia, Holothuria and Pearsonothuria, all of which are included in the family Holothuriidae. The tubules can be discharged through the anus when the sea cucumber is stressed. They lengthen when they come into contact with seawater and become adhesive when they encounter objects so that they function as a defence against potential predators. They are named after the French zoologist Georges Cuvier, who first described them.