Prakash's lab work runs the gamut from small-scale problems to field work. The researchers at Stanford were puzzled, however, when they filmed the parasite swimming at high speeds. Cercaria, the free-swimming form of schistosoma, gets around by beating its forked tail back and forth. According to mathematical theories developed over the past 50 years, this reciprocal beating at small scales shouldn't enable cercaria to move at all, but merely bob in place, essentially treading water. 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.