Abstract
A survey of freshwater hyphomycetes was conducted at Ton Nga Chang Wildlife-Sanctuary, Songkhla, Thailand. The viability of aquatic hyphomycetes trapped in fresh and old foam was estimated using tetrazolium bromide (MTT) staining. Percentages of conidia with at least one viable cell was in the range of 44-77% and 42-69% in fresh and old foam, respectively. Viability of conidia in fresh and old foam was not significantly different at (P>0.05). Anguillospora sp., Helicomyces sp., Thozetella sp. and Volutella sp. were tested for their viability under laboratory conditions. The conidial viability after aeration in water remained at 83-88%, after seven days. However only 3-45% remained viable after drying for 10 hours. Sixty-two fungi were recorded during this study, including 48 species in 34 genera and 14 unidentified taxa.