chytrid

Chytrids are fungi in the phylum Chytridiomycota, among the earliest-diverging lineages within the fungal kingdom. They are characterized by their production of motile zoospores with a single posterior flagellum, a feature that links them to aquatic environments and distinguishes them from most other fungi. Most chytrids are unicellular or have simple thalli, and several forms are coenocytic. They inhabit fresh water, soils moist with organic matter, and in some cases marine environments. Many chytrids feed as saprobes on dead organic material, while others are parasites of algae, plants, or animals, including amphibians.

Reproduction typically involves zoospores that swim using their flagellum and settle to form new thalli or sporangia. Asexual reproduction is common, with zoospores released from sporangia to colonize substrates. Sexual reproduction occurs in some species through the formation of resting sporangia or zygotes, contributing to genetic diversity.

Ecological and economic importance is notable. Some chytrids decompose organic matter in aquatic ecosystems, contributing to nutrient cycling. Others are plant pathogens, such as Synchytrium endobioticum, which causes potato wart disease. The best known contemporary concerns involve amphibian health: Batrachochytrium dendrobatidis and B. salamandrivorans cause chytridiomycosis, associated with mass declines and extinctions in amphibian populations worldwide. Because chytrids represent a basal fungal lineage, their study helps illuminate fungal evolution and ecology.

Taxonomically, chytrids comprise the phylum Chytridiomycota, containing several hundred described species across diverse genera.