Lichen anatomy and physiology the Ascomycota, with about 40% of species forming such an association. Some of these lichenized fungi occur in orders with nonlichenized fungi that live as saprotrophs or plant parasites (for example, the Leotiales, Dothideales, and Pezizales). Other lichen fungi occur in only five orders in which all members are engaged in this habit (Orders Graphidales, Gyalectales, Peltigerales, Pertusariales, and Teloschistales). Lichenized and nonlichenized fungi can even be found in the same genus or species. Overall, about 98% of lichens have an ascomycetous mycobiont. Next to the Ascomycota, the largest number of lichenized fungi occur in the unassigned fungi imperfecti. Comparatively
Parasites in fiction subservient puppets, able to crawl but unable to act independently; or the barnacle-like crustaceans that castrate their crab hosts, or grow into their brains, altering their behaviour to care for the young barnacles. All the same, a 2013 poll of scientists and engineers by "Popular Mechanics" magazine revealed that the parasite-based science fiction films "The War of the Worlds" (Byron Haskin, 1953) and "Alien" were among their top ten favourites. Several types of parasite, corresponding more or less accurately to some of those known in biology, are found in literature. These include haematophagic parasites (fictional vampires), parasitoids, behaviour-altering parasites, brood