1 Introduction Active fluids exhibit spontaneous turbulent flows at low Reynolds number (Re), which have been observed in bacterial suspensions,[1-3] sperm swarms,[4] mixtures of microtubules and motor proteins,[5-7] epithelial cells,[8, 9] and artificial motile colloids.[10] These active fluids are constituted of a large number of self-driven agents that inject kinetic energy individually into the systems. These agents generate active stress and drive the formation of turbulence.
