Stramenopiles Oomycetes Laura Huerta Margulis, L., and K. V. Schwartz. 2000. Five kingdoms: an illustrated guide to the phyla of life on earth. W. H. Freeman and Co., New York, N.Y. Oomycetes form a diverse group of fungus-like eukaryotic microorganisms, also known as water molds, that include both saprophytes and pathogens of plants, insects, crustaceans, fish, vertebrate animals, and various microorganisms.