  We present the observational properties of the dwarf galaxy population (Mr >
M*+1) corresponding to one of the largest samples of spectroscopically
confirmed galaxy cluster members reported in the literature. We have observed
that red dwarf galaxies (u-r > 2.22) share the same cluster environment as the
brightest cluster members (Mr < -21), but are not in dynamical equilibrium. We
computed the dwarf-to-giant ratio (DGR) using a spectroscopically selected
sample. The DGR was found to vary with clustercentric distance, essentially due
to the blue dwarf population (u-r < 2.22). The u-r color of red dwarf galaxies
was independent of their environment and similar to the color of red isolated
dwarfs. Blue dwarf galaxies located outside r200 show similar u-r colors to
those of the field population, while strong reddening was observed toward the
cluster center. We also present evidence that the fraction of red to blue dwarf
galaxies in clusters is larger in the innermost cluster regions. We conclude
that the present red dwarf population observed in the central regions of nearby
galaxy clusters could be related to the blue dwarf population observed in
clusters at high redshift.
