  We examine the dependence of the dynamics of three-dimensional active fluids
on persistence time $\tau_p$ and average self-propulsion force $f$. In the
large persistence time limit many properties of these fluids become
$\tau_p$-independent. These properties include the mean squared velocity, the
self-intermediate scattering function, the shear-stress correlation function
and the low-shear-rate viscosity. We find that for a given $f$ in the large
$\tau_p$ limit the mean squared displacement is independent of the persistence
time for times shorter than $\tau_p$ and the long-time self-diffusion
coefficient is proportional to the persistence time. For a large range of
self-propulsion forces the large persistence time limits of many properties
depend on $f$ as power laws.
