  We report measurements of magnon spin transport in a spinel ferrite,
magnesium aluminum ferrite $\mathrm{MgAl_{0.5}Fe_{1.5}O_4}$ (MAFO), which has a
substantial in-plane four-fold magnetic anisotropy. We observe spin diffusion
lengths $> 0.8$ $\mathrm{\mu m}$ at room temperature in 6 nm films, with spin
diffusion length 30% longer along the easy axes compared to the hard axes. The
sign of this difference is opposite to the effects just of anisotropy in the
magnetic energy for a uniform magnetic state. We suggest instead that
accounting for anisotropy in exchange stiffness is necessary to explain these
results.
