  For the kappa-symmetric super IIA D-brane action by the canonical approach we
construct an equivalent effective action which is characterized by an auxiliary
scalar field. By analyzing the canonical equations of motion for the
kappa-symmetry-gauge-fixed action we find a suitable conformal-like covariant
gauge fixing of reparametrization symmetry to obtain a simplified effective
action where the non-linear square root structure is removed. We discuss how
the two effective actions are connected.
