  We apply the magneto-roton theory of the fractional quantum Hall effect to
study the collective excitation spectrum of rotating dipolar Fermi gases. The
predicted spectrum has a finite energy gap in the long wavelength limit and a
roton minimum at finite wave vector. The roton minimum being deepened from
filling factor 1/3 to filling factor 1/5 is a signature of incipient
crystallization near filling factor 1/7. We also demonstrate that there are no
low-lying single-particle excitations below the roton mode. The
fractional-quantum-Hall fluid rotating dipolar fermions behaves as an
incompressible superfluid at low temperature.
