Anaerobic fungi are the sole members of the phylum Neocallimstigomycota.
Within this phylum, there is only one class (Neocallimastigomycetes), one order (Neocallimastigales) and one family (Neocallimastigaceae).
Wthin the Neocallimastigaceae, there are currently 20 recognized anaerobic fungal genera. Many more genera remain to be isolated and/or characterized.
The 20 characterized anaerobic fungal genera are (listed in chronological order of characterization): Neocallimastix, Piromyces, Caecomyces, Orpinomyces, Anaeromyces, Cyllamyces, Buwchfawromyces, Oontomyces, Pecoramyces, Feramyces, Liebetanzomyces, Agriosomyces, Aklioshbomyces, Capellomyces, Ghazallomyces, Joblinomyces, Khoyollomyces, Tahromyces, Aestipascuomyces and Paucimyces.
A table providing an up to date overview of the key morphology features of all 20 different anaerobic fungal genera (modified from the review of Hess et al (2020)) is available to download as a pdf here.
Pictured below is a phylogenetic tree of anaerobic fungal LSU sequences, illustrating the relatedness of the different anaerobic fungal genera to each other.

As of January 2021, we will regularly feature details of one of these genera – building up an online resource that describes all these different anaerobic fungal genera.
This month we’d like to introduce you to the anaerobic fungal genus Aestipascuomyces.
Previous featured genera include: