  We present the results of a redshift survey of both cluster and intercluster
galaxies in the central part of the Shapley Concentration, the richest
supercluster of clusters in the nearby Universe, consisting of ~2000 radial
velocities.
  We estimate the total overdensity in galaxies of the supercluster and its
mass and we discuss the cosmological implications of these results.
  Moreover, using a Principal Components Analysis technique, we study the
influence of the cluster and supercluster dynamics on the galaxy spectral
morphology.
