THOUSANDS OF SEXES. “There are examples in which there are more than two mating types or sexes. These include the basidiomycete fungi we have discussed that have literally thousands and thousands and thousands of different mating types (multisexual) including Coprinopsis cinerea, the slime mold Dictyostelium with its three mating types (trisexual), and the ciliate Tetrahymena with seven (septasexual).”
http://www.sciencedirect.com/science/article/pii/S1749461315000391