Key ecological roles for zoosporic true fungi in aquatic habitats

The “Aquatic Phycomycetes” (sensu Sparrow) ( 1 ) constitutes an ecologically and economically important assemblage of eukaryotic microorganisms that share many morphological traits and ecological functions and interact with each other in the same aquatic ecosystems. There is molecular and structural evidence that the aquatic phycomycetes is a diverse, polyphyletic assemblage of species. For many years little research has been conducted with the aquatic phycomycetes, possibly because they were thought to be ecologically and commercially insignificant, but this perception has recently changed. Many of these species have been found to play key roles in biomass conversion in food webs ( Fig. 1 ) and in the carbon cycle ( 2 ).