  Degeneracy patterns and hyper-multiplet structure in the spectrum of the
su($m|n$) supersymmetric Polychronakos spin chain are studied by use of the
"motif''. Using the recursion relation of the supersymmetric Rogers-Szeg{\"o}
polynomials which are closely related to the partition function of the $N$ spin
chain, we give the representation for motif in terms of the supersymmetric skew
Young diagrams. We also study the distribution function for quasi-particles.
The character formulae for $N\to \infty$ are briefly discussed.
