Sea urchins grip rocks with hydraulic power

Sea urchins use hundreds of tiny tube feet to cling to rocks with remarkable hydraulic power. These feet are part of a water vascular system, a network of fluid-filled canals acting like a built-in pump. By contracting muscles, the urchin extends its tube feet, which end in suction-like discs, providing a strong hold against waves. This adaptation is crucial for survival in turbulent coastal waters, preventing dislodgement.