Chytrids are one of the earliest diverging fungal lineages, and their membership in kingdom Fungi is demonstrated with chitin cell walls, a posterior whiplash flagellum, absorptive nutrition, use of glycogen as an energy storage compound, and synthesis of lysine by the α-amino adipic acid (AAA) pathway.

[5][6] Species of Chytridiomycota have traditionally been delineated and classified based on development, morphology, substrate, and method of zoospore discharge.

In older classifications, chytrids, except the recently established order Spizellomycetales, were placed in the class Phycomycetes under the subphylum Myxomycophyta of the kingdom Fungi.

It is generally accepted that the resulting zygote forms a resting spore, which functions as a means of surviving adverse conditions.

Once fertilized, the zygote either becomes an encysted or motile oospore,[4] which ultimately becomes a resting spore that will later germinate and give rise to new zoosporangia.

Operculate discharge involves the complete or incomplete detachment of a lid-like structure, called an operculum, allowing the zoospores out of the sporangium.

[7][4] However, recent taxonomic work has demonstrated that this ubiquitous and cosmopolitan morphospecies hide cryptic diversity at the genetic and ultrastructural levels.

[4] However, recent molecular inventories of lakes during the summer indicate that chytrids are an active, diverse part of the eukaryotic microbial community.

[23] The population of the Chytridiomycota species are able to be supported even though there is a lack of plant life in these frozen regions due to the large amounts of water in periglacial soil and pollen blowing up from below the timberline.

[28] The process leading to frog mortality is thought to be the loss of essential ions through pores made in the epidermal cells by the chytrid during its replication.

[29] Recent research has revealed that elevating salt levels slightly may be able to cure chytridiomycosis in some Australian frog species,[30] although further experimentation is needed.

[4] The earliest fossils of chytrids are from the Scottish Rhynie chert, a Devonian-age lagerstätte with anatomical preservation of plants and fungi.

[35] Holocarpic chytrid remains were found in cherts from Combres in central France that date back to the late Visean.

[36] Other chytrid-like fossils were found in cherts from the upper Pennsylvanian in the Saint-Etienne Basin in France, dating between 300~350 ma.

[37] The novel Tom Clancy's Splinter Cell: Fallout (2007) features a species of chytrid that feeds on petroleum and oil-based products.

It is then used by Islamic extremists in an attempt to destroy the world's oil supplies, thereby taking away the technological advantage of the United States.