The digging motions of a razor clam.
The soft, pale foot of a six-inch long razor clam burrows through sand at an impressive rate of four body lengths per minute (video). When scientists put muscles in the razor clam to the strength test though, they found that its foot was only 1/10 as strong as it would need to be to dig so fast. What gives? The sand, literally.
Instead of relying on brute force, the burrowing razor clam turns the sediment around itself into quicksand, according to a study published in the Journal of Experimental Biology. And as Hollywood has taught us well, it’s easy to sink in quicksand.* The razor clam pulls its shell up, creating a vacuum that sucks water into the space surrounding its body. Quicksand is just sand with enough water between all its particles so that it no longer holds any weight, making it easy for the razor clam to tunnel down. Although most (big) pools of quicksand are created by earthquakes or flowing water, the razor clam’s small scale strategy is quite effective. In fact, the little buggers are so fast that recreational clam digging actually takes some practice.
*The human body is actually too buoyant to sink beyond the armpits in quicksand. So no, you can’t die of drowning in quicksand but you can get stuck and die of dehydration. Comforting thought, right?
Image via Winter et al. / J. Experimental Bio