Similar aquatic biological creatures have struggled to break this mathematical locomotive paradox by varying their tail strokes to beat in non-symmetric cycles at small scales. For schistosomas, innovation comes from their unusual forked tail, which forms a "T-shape" joint. This passive torsional joint interacts with the fluid in surprising ways to break this time-varying symmetry -- hence the researchers call this a T-joint swimmer. Such a simple way to break this symmetry had never been seen before, Prakash noted.