Zoospores of a Chlamydomyzium oviparasiticum (Oomycota) species have encysted on a nematode egg. The zoospore of the fungus is attracted to the egg by chemical secretions that leak from the egg. Zoospores encyst on the surface of the egg, penetrate the wall and then proliferate inside as it consumes the contents. Originally described in the genus Lagenidium now shown to attack adult nematodes (?) as well as rotifer eggs.