  We study the possibility of correctly identifying superclusters, from the
smooth galaxy density field of the PSCz redshift catalogue, and of recovering
their true shapes in the presence of a bias introduced by the coupling between
the selection function and the constant radius smoothing. Using simulations we
quantify such systematic biases in the smoothed PSCz density field and after
applying the necessary corrections we study the PSCz supercluster multiplicity
and morphologies using a differential geometry definition of shape. Our results
strongly suggest that filamentariness is the dominant morphological feature of
PSCz superclusters. Finally, we compare our results with those expected in
three different cosmological models and find that the LCDM model performs
better than Omega_m=1 CDM models.
