  We study the basic relation between skew-symmetric Lotka-Volterra systems and
graphs, both at the level of objects and morphisms, and derive a classification
from it of skew-symmetric Lotka-Volterra systems in terms of graphs as well as
in terms of irreducible weighted graphs. We also obtain a description of their
automorphism groups and of the relations which exist between these groups. The
central notion introduced and used is that of decloning of graphs and of
Lotka-Volterra systems. We also give a functorial interpretation of the results
which we obtain.
