Aphanomyces

Aphanomyces is a genus of water moulds. As of 2003 there were about 45 described species. Many of these water moulds are known as economically important pathogens of species of plants and animals, including fish, crustaceans, and agricultural crop plants. Aphanomyces water moulds are "one of the most important yield-limiting factors in production of legumes and sugarbeet."