  The momentum conservation law for general dissipationless reduced-fluid
(e.g., gyrofluid) models is derived by Noether method from a variational
principle. The reduced-fluid momentum density and the reduced-fluid canonical
momentum-stress tensor both exhibit polarization and magnetization effects as
well as an internal torque associated with dynamical reduction. As an
application, we derive an explicit gyrofluid toroidal angular-momentum
conservation law for axisymmetric toroidal magnetized plasmas.
