Abstract
A collection of fungi was isolated from macroalgae of the genera Gracilaria, Enteromorpha and Ulva in the estuary Ria de Aveiro in Portugal. These isolates were characterized through a multilocus phylogeny based on ITS region of the ribosomal DNA, beta-tubulin (tub2) and translation elongation factor 1 alpha (tef1-α) sequences, in conjunction with morphological and physiological data. These analyses showed that the isolates represented an unknown fungus for which a new genus, Neptunomyces gen. nov. and a new species, Neptunomyces aureus sp. nov. are proposed. Phylogenetic analyses supported the affiliation of this new taxon to the family Didymosphaeriaceae.