  We analyze the anisotropy of turbulence in an electrically conducting fluid
in the presence of a uniform magnetic field, for low magnetic Reynolds number,
using the quasi-static approximation. In the linear limit, the kinetic energy
of velocity components normal to the magnetic field decays faster than the
kinetic energy of component along the magnetic field [Moffatt, JFM 28, 1967].
However, numerous numerical studies predict a different behaviour, wherein the
final state is characterized by dominant horizontal energy. We investigate the
corresponding nonlinear phenomenon using Direct Numerical Simulations. The
initial temporal evolution of the decaying flow indicates that the turbulence
is very similar to the so-called "two-and-a-half-dimensional" flow [Montgomery
& Turner, Phys. Fluids 25(2), 1982] and we offer an explanation for the
dominance of horizontal kinetic energy.
