Free-living nematodes, commonly known as eelworms, eat bacteria in the soil and may succumb to infection by delicate endoparasitic fungi. In the wild these fungi are host-dependent and infect nematodes with small unicellular spores that either lodge inside the nematode following ingestion, or adhere to the nematode cuticle. Some endoparasites, such as Drechmeria coniospora and Harposporium leptospira, are readily isolated, ubiquitous species, infecting common soil nematodes in a variety of substrates. Others, like the elusive Plesiospora globosa, are seldom seen because they are host-specific for rarer species of nematode occurring in specific habitats.
