M. americanus may refer to: Menticirrhus americanus, a kingcroaker species in the genus Menticirrhus Mergus americanus, a duck species, now a subspecies of the common merganser Merops americanus, a bee eater from the Philippines Metasiro americanus, a harvestman species in the genus Metasiro Monomitopus americanus, an eel species in the genus Monomitopus Morone americanus, a bass species
See also Americanus (disambiguation)