  A recently presented anisotropic generalization of the multicomponent
supersymmetric $t-J$ model in one dimension is investigated. This model of
fermions with general spin-$S$ is solved by Bethe ansatz for the ground state
and the low-lying excitations. Due to the anisotropy of the interaction the
model possesses $2S$ massive modes and one single gapless excitation. The
physical properties indicate the existence of Cooper-type multiplets of $2S+1$
fermions with finite binding energy. The critical behaviour is described by a
$c=1$ conformal field theory with continuously varying exponents depending on
the particle density. There are two distinct regimes of the phase diagram with
dominating density-density and multiplet-multiplet correlations, respectively.
The effective mass of the charge carriers is calculated. In comparison to the
limit of isotropic interactions the mass is strongly enhanced in general.
