When submerged, platypuses close their nostrils and ear openings to prevent water entry. This ensures that sensitive electroreceptors and hearing mechanisms function properly. It also protects against debris and sediment while foraging in riverbeds. Combined with waterproof fur, this adaptation allows long underwater excursions. Juveniles learn to coordinate breathing, nostril closure, and diving techniques. It is essential for semi-aquatic life in fast-flowing streams. Such precise anatomical control is rare in mammals.
Protective closure enhances underwater sensory function and survival.
It supports efficient and safe diving behavior.
Platypuses keep water out of nostrils and ears when submerged.
National Geographic (nationalgeographic.com)