Seasonal fluctuations of aquatic fungi recovered from Egyptian soil (Delta Region)

One hundred and eleven identified and seven unidentified species in addition to 5 varieties belonging to forty‐three aquatic fungal genera were recovered from 452 soil samples collected randomly from different localities in Nile Delta and Suez canal regions including eleven governorates. The investigated soil samples were collected seasonally during the period from autumn 1990 to summer 1991 (113 samples each season). The richest season (85 identified and 5 unidentified species in addition to 2 varieties) in aquatic fungi was the winter season (10.0‐15.5°C) whereas the poorest (32 identified and 5 unidentified species in addition to one variety) was summer (24.0‐27.5°C). The richest soil samples in aquatic fungi were those of low or moderate temperature seasons, high contents of organic matter and considerably poor in total soluble salts. The pH value did not show any regular seasonal variation and did not exhibit any considerable influence on fungal populations. Some aquatic fungal genera and species were disappeared completely in certain seasons and vice versa. The most dominant aquatic fungal genera were Pythium, Allomyces, Aqualinderella and Nowa‐kowskiella. The commonest aquatic fungal species were Allomyces anomalus, Aqualinderella fermentans, Nowakowskiella elegans, Blastocladiopsis parva and Dictyuchus sterilis.