How does barnacle survive both in and out of the water?

Barnacles survive both in and out of water by tightly closing their shells to retain moisture when the tide recedes. They have adapted to withstand desiccation by sealing their bodies and reducing water loss. Additionally, barnacles can filter feed when submerged, using their specialized appendages to capture food particles. This ability to endure varying conditions allows them to thrive in intertidal zones.