  We investigate the behavior of dark solitons in a superfluid Fermi gas along
the BCS-BEC crossover by solving the Bogoliubov - de Gennes equations and
looking for real and odd solutions for the order parameter. We show that in the
resonance unitary region, where the scattering length is large, the density
profile of the soliton has a deep minimum, differently from what happens in the
BCS regime. The superfluid gap is found to be significantly quenched by the
presence of the soliton due to the occurrence of Andreev fermionic bound states
localized near the nodal plane of the order parameter.
