Phase contrast micrograph of spore formation and release in Aspergillus, an ascomycete, using a semi-thin stained section stained blue. Chains of asexual spores (conidia) bud off from the projections (phialides) on special hyphae called conidiophores, one of which is shown here, which in Aspergillus terminate in a characteristic 'mop head' . Most Aspergillus species are saprophytes, feeding on on decaying organic matter. Some species produce mycotoxins that can bulid up in livestock or humans that eat infected foodstuffs. Some are respiratory tract pathogens, causing lung diseases in humans, poultry and other animals when the spores are inhaled, for example, farmer's lung or aspergillosus. Fermentation by certain Aspergillus species is involved in the production of soy sauce.