Order Chytridiales is a group of primitive fungi that belong to the class Chytridiomycetes. There are several synonyms that have been used to refer to this group of fungi, including Chytridio-mycetes, Chytridiales incertae sedis, and Gonapodyales. These synonyms are based on different taxonomic classification systems that have been used over time to classify organisms. The Chytridiales are unique in that they have a zoosporic life cycle, where they produce flagellated spores that swim through water, allowing them to colonize various habitats. Some notable members of the Chytridiales include Batrachochytrium dendrobatidis, which is responsible for causing the decline of amphibian populations worldwide, and Rhizophydium planktonicum, which plays a significant role in the marine food web.