Many species have developed specialized hyphal structures for nutrient uptake from living hosts; examples include haustoria in plant-parasitic species of most fungal phyla, and arbuscules of several mycorrhizal fungi, which penetrate into the host cells to consume nutrients [REF].
Although fungi are opisthokonts-a grouping of evolutionarily related organisms broadly characterized by a single posterior flagellum-all phyla except for the chytrids have lost their posterior flagella [REF].