title: Key Ecological Roles for Zoosporic True Fungi in Aquatic Habitats.
abstract: The diversity and abundance of zoosporic true fungi have been analyzed recently using fungal sequence libraries and advances in molecular methods, such as high-throughput sequencing. This review focuses on four evolutionary primitive true fungal phyla: the Aphelidea, Chytridiomycota, Neocallimastigomycota, and Rosellida (Cryptomycota), most species of which are not polycentric or mycelial (filamentous), rather they tend to be primarily monocentric (unicellular). Zoosporic fungi appear to be both abundant and diverse in many aquatic habitats around the world, with abundance often exceeding other fungal phyla in these habitats, and numerous novel genetic sequences identified. Zoosporic fungi are able to survive extreme conditions, such as high and extremely low pH; however, more work remains to be done. They appear to have important ecological roles as saprobes in decomposition of particulate organic substrates, pollen, plant litter, and dead animals; as parasites of zooplankton and algae; as parasites of vertebrate animals (such as frogs); and as symbionts in the digestive tracts of mammals. Some chytrids cause economically important diseases of plants and animals. They regulate sizes of phytoplankton populations. Further metagenomics surveys of aquatic ecosystems are expected to enlarge our knowledge of the diversity of true zoosporic fungi. Coupled with studies on their functional ecology, we are moving closer to unraveling the role of zoosporic fungi in carbon cycling and the impact of climate change on zoosporic fungal populations.
authors.affiliation: School of Life and Environmental Sciences, Faculty of Science, University of Sydney, NSW 2006, Australia.
authors.forename: Frank H
authors.initials: FH
authors.lastname: Gleason
authors.affiliation: Faculty of Natural Resource Sciences, University of Akureyri, Borgir v. Nordurslod, IS 600 Akureyri, Iceland.|BioPol ehf., Einbúastig 2, 545 Skagaströnd, Iceland.
authors.forename: Bettina
authors.initials: B
authors.lastname: Scholz
authors.affiliation: School of Life and Environmental Sciences, Faculty of Science, University of Sydney, NSW 2006, Australia.
authors.forename: Thomas G
authors.initials: TG
authors.lastname: Jephcott
authors.affiliation: School of Life and Environmental Sciences, Faculty of Science, University of Sydney, NSW 2006, Australia.
authors.forename: Floris F
authors.initials: FF
authors.lastname: van Ogtrop
authors.affiliation: School of Life and Environmental Sciences, Faculty of Science, University of Sydney, NSW 2006, Australia.
authors.forename: Linda
authors.initials: L
authors.lastname: Henderson
authors.affiliation: School of Life and Environmental Sciences, Faculty of Science, University of Sydney, NSW 2006, Australia.
authors.forename: Osu
authors.initials: O
authors.lastname: Lilje
authors.affiliation: AgResearch Ltd., Grasslands Research Centre, Palmerston North, New Zealand.
authors.forename: Sandra
authors.initials: S
authors.lastname: Kittelmann
authors.affiliation: School of Science, Faculty of Health Sciences, Australian Catholic University, NSW 2059, Australia.
authors.forename: Deborah J
authors.initials: DJ
authors.lastname: Macarthur
mesh_terms: D000818:Animals; D017753:Ecosystem; D005658:Fungi / Q000166:cytology* / Q000254:growth & development*; D013172:Spores, Fungal / Q000166:cytology*; D013559:Symbiosis; D014871:Water Microbiology