Ecology of aquatic nematode-trapping hyphomycetes in southwestern China

Aquatic nematode-trapping hyphomycetes have rarely been studied. The current study examined 1000 waterlogged soil samples in order to systematically investigate resources of aquatic nematode-trapping hyphomycetes and to compare species diversity and community similarities in polluted and unpolluted aquatic environments. Many nematode-trapping hyphomycetes live in shallow freshwater (at a water depth of 20 cm). No nematode-trapping hyphomycetes were isolated from the 20 samples collected at the bottom (at a water depth of 4 m) of Dianchi Lake. Among the 35 isolated species of predacious fungi, Arthrobotrys oligospora, A. musiformis, Monacrosporium thaumasium and M. longiphorum were the most common species. Species with adhesive networks were the most frequently isolated. The similarity indices between fungal communities living in similar aquatic environments were higher than those from dissimilar aquatic environments, and the level of species diversity for the brooks of the nature reserves was higher than that for the contaminated lake or river.