Species of Phytophthora and Pythium as Nematode-destroying Fungi.

Pythium monospermum,, P. aphanidermatum, and Phytophthora palmivora were found to be capable of destroying certain nonstylet-bearing nematodes through endozoic parasitism by hyphae from ingested zoospores. Hyphae of P. monospermum parasitized nematode eggs but could not capture or otherwise prey upon living nematodes. We suggest that endoparasitism of free-living nematodes may be common among Oomycetes in nature.