Antivarieties of unars

A complete description of the lattice of all antivarieties of unars is given. It is stated that there exist continuum many antivarieties of unars not having an independent basis of anti-identities and a necessary and sufficient condition is specified under which a finite unar has an independent or finite basis of anti-identities. In addition, it is proved that the lattice of all antivarieties of unars is isomorphic to a lattice of $$ {{\mathcal A}_{1,1}} $$ -antivarieties, where $$ {{\mathcal A}_{1,1}} $$ is a variety of unary algebras of a signature   defined by identities f(g(x)) = g(f(x)) = x.