These fungi are heterotrophic eukaryotes that use decaying organic material as a food source. They are called saprophytes. Examples include yeast and mushrooms. Fungi have filamentous structures called hyphae that can come together to form a visible mat known as mycelium. They can reproduce both sexually, through the fusion of hyphae with different mating types, and asexually via spores. Fungal spores are produced via specialized structures like sporangiophores or through fragmentation. Fungi play an important ecological role in decomposing dead organic matter and recycling nutrients.