Paraphysoderma sedebokerense , gen. et sp. nov., an aplanosporic relative of Physoderma (Blastocladiomycota)

A monocentric blastocladialean fungus was identified as a parasite of the green alga Haematococcus pluvialis in aquaculture and isolated into pure culture. Phylogenetic analysis suggests the fungus is a sister taxon to the obligately biotrophic plant parasitic genus Physoderma. The parasite, which has not been observed to reproduce by zoospores, instead forms amoeboid aplanospores. We formally describe the new genus and species Paraphysoderma sedebokerense to accommodate this unusual member of the Blastocladiomycota.