<p>Surface electromagnetic waves in graphene in a static magnetic field have been theoretically studied in the hydrodynamic regime. The antisymmetric conductivity tensor of graphene is obtained taking into account the spatial dispersion arising due to the effect of hydrodynamic pressure. It is shown that the spatial dispersion leads to a uniaxial anisotropy of the graphene conductivity in addition to the gyrotropy of graphene arising in the magnetic field. Dependences of the frequency of magnetoplasmoacoustic waves on the dispersion, magnetic field, and electron density are calculated. At large wave vectors, the magnetoplasmon is transformed into electronic magnetosound with a nearly linear dependence of the frequency on the wave vector. It is shown that the magnetic gyrotropy of graphene does not hybridize the polarization states of magnetoplasmons in the quasielectrostatic regime.</p>