What kind of fungus is Saprolegnia?

Saprolegnia is a genus of water mold belonging to the class Oomycetes, which are often referred to as "water molds." These organisms are typically found in freshwater environments and are known for their filamentous structures. Saprolegnia species are saprophytic, feeding on decaying organic matter, but they can also act as pathogens, particularly affecting fish and amphibians by causing diseases like saprolegniasis. Their growth is often characterized by fluffy, white or grayish tufts on affected organisms or surfaces.