  We analyze the concept of entanglement for multipartite system with bosonic
and fermionic constituents and its generalization to systems with arbitrary
parastatistics. We use the representation theory of symmetry groups to
formulate a unified approach to this problem in terms of simple tensors with
appropriate symmetry. For an arbitrary parastatistics, we define the S-rank
generalizing the notion of the Schmidt rank. The S-rank, defined for all types
of tensors, serves for distinguishing entanglement of pure states. In addition,
for Bose and Fermi statistics, we construct an analog of the Jamiolkowski
isomorphism.
