Wallemia ichthyophaga is one of the three species of the genus Wallemia, which in turn is the only genus of the class Wallemiomycetes. The phylogenetic origin of the lineage was placed to various parts of Basidiomycota, but according to the analysis of larger datasets it is a (495-million-years-old) sister group of Agaricomycotina. The genome of the fungus contains no mating type locus and the species appears to be asexual.