| Noun | 1. | class Chytridiomycetes - a class of mostly aquatic fungi; saprophytic or parasitic on algae or fungi or plants class - (biology) a taxonomic group containing one or more orders Mastigomycota, Mastigomycotina, subdivision Mastigomycota, subdivision Mastigomycotina - fungi in which the spores and gametes are motile; in some systems placed in the Phycomycetes group with the Zygomycota Chytridiales, order Chytridiales - simple aquatic fungi mostly saprophytic but some parasitic on higher plants or animals or fresh water fungi; sometimes placed in class Oomycetes Blastocladiales, order Blastocladiales - fungi that carry out asexual reproduction by thick-walled resting spores that produce zoospores upon germination; sometimes placed in class Oomycetes |