Advances in the Study of So‐called Aquatic Hyphomycetes

Abstract

Progress in the study of the freshwater aquatic fungal flora (mainly hyphomycetes) of submerged decaying leaves of dicotyledonous trees and shrubs, since the discovery of the flora in 1942, is reviewed. The abundant occurrence of liberated conidia, which tend to be of distinctive form, in persistent foam on a stream is noted and illustrated by an example from Scotland. Developments in the taxonomy of these fungi since 1942 are noted. About 60 genera and around 120 species are now recorded. In a number the perfect stage has been discovered. In most cases it has proved to be an ascomycete, but it is sometimes a basidiomycete. Conidium development in aquatic hyphomycetes is discussed in the light of recent views on the classification of conidial types. It is argued that the most valid distinction is between phialoconidia and other types, rather than between those of blastic and those of thallic development. Dispersal is discussed with special reference to upstream spread and the problem of dispersal from one isolated water system to another. Finally, attention is given to the ecology and general physiology of these fungi. Their possible importance in processing decaying leaves for subsequent consumption by small aquatic animals is considered. The terrestrial occurrence of many “aquatic hyphomycetes” is noted and it is suggested that “amphibious hyphomycetes” might be a better term.

The simple-septate basidiomycetes: a synopsis

“…Conidia of Classicula are similar to those of Jaculispora in size and in form: in both species, the conidia are naviculate, with three to four distal setose branches. These conidia in Classicula and in Jaculispora with broadly diverging branches resemble those of aquatic hyphomycetes (Ingold 1979). In fact, as noted by Marvanová and Bandoni (1987), Classicula and Jaculispora were frequently found in freshwater habitats.…”

“…is also a member of the Cystobasidiomycetes. The conidia of Cyrenella with radiating arms resemble those of aquatic hyphomycetes and may have evolved as an adaptation to water dispersal (Ingold 1979). This fungus is dimorphic and produces an orange-pigmented yeast stage.…”

Hyphomycetes in the stream at the Royal Botanic Garden, Edinburgh and notes on their distribution in Scotland

“…Slides were made and permanently sealed. Ingold (1973Ingold ( , 1975Ingold ( & 1979, Bandoni (1972), Crane (1967), Nilson (1964 and Brathen (1984) were consulted for identification of the species.…”

Fungi and bacteria associated with pine (Pinus kesiya Royle) needles and teak (Tectona grandis L.) leaf litters during processing in a freshwater lake

“…The conspicuous absence of aquatic hyphomycetes (Ingold 1979) might also be due to the unsuitability of the plate culture technique for this group of fungi, although this group is rarely found in lakes and ponds. Further, they are generally absent from the gymnosermic needles (Ingold 1976) except for a few isolations by Barlocher & Oertli (1978).…”