Mackerel sharks [UK and USA], Familia
– synonym of Lamnidae, Familia
Macroparalepis, Genus
Macroramphosidae, Familia
Macroramphosus, Genus
Macrostomias, Genus
Macrouridae, Familia
Macrourus, Genus
Makaira, Genus
Malacocephalus, Genus
Malacosteidae, Familia
Malacosteus, Genus
Malarmats [France and Belgium], Familia
– synonym of Peristediidae, Familia
Mallotus, Genus
Man-of-war fishes [UK and USA], Familia
– synonym of Nomeidae, Familia
Mantes [France and Belgium], Familia
– synonym of Mobulidae, Familia
Maquereaux [France and Belgium], Familia
– synonym of Scombridae, Familia
Margrethia, Genus
Marlins [UK and USA], Familia
– synonym of Istiophoridae, Familia
Masturus, Genus
Mauligobius, Genus
Maulisia, Genus
Maurolicus, Genus
Megalomycteridae, Familia
Megalopidae, Familia
Melamphaes, Genus
Melamphaidae, Familia
Melanocetidae, Familia
Melanocetus, Genus
Melanogrammus, Genus
Melanonidae, Familia
Melanonus, Genus
Melanostigma, Genus
Melanostomias, Genus
Melanostomiidae, Familia
Melodichthys, Genus
Melodichthys Nielsen and Cohen, 1986
– synonym of Melodichthys, Genus
Merlangius, Genus
Merlucciidae, Familia
Merluccius, Genus
Merluccius Rafinesque, 1810
– synonym of Merluccius, Genus
Merlus [France and Belgium], Familia
– synonym of Merlucciidae, Familia
Mesogobius, Genus
Meteoria, Genus
Micrenophrys, Genus
Microchirus, Genus
Microichthys, Genus
Microlophichthys, Genus
Micromesistius, Genus
Microstoma, Genus
Microstomus, Genus
Milandres [France and Belgium], Familia
– synonym of Hemigaleidae, Familia
Millerigobius, Genus
Minyichthys, Genus
Mirapinna, Genus
Mirapinnidae, Familia
Mirognathus, Genus
Mitsukurina, Genus
Mitsukurinidae, Familia
Mobula, Genus
Mobulidae, Familia
Mola, Genus
Molidae, Familia
Molva, Genus
Monacanthidae, Familia
Monishia, Genus
Monochirus, Genus
Monognathidae, Familia
Monognathus, Genus
Monomitopus, Genus
Mora, Genus
Moray eels [UK and USA], Familia
– synonym of Muraenidae, Familia
Moridae, Familia
Moronidae, Familia
Mosaic-scaled fishes [UK and USA], Familia
– synonym of Megalomycteridae, Familia
Mourines [France and Belgium], Familia
– synonym of Rhinopteridae, Familia
Mugil, Genus
Mugilidae, Familia
Mugiloidei, Subordo
Mullidae, Familia
Mullus, Genus
Muraena, Genus
Muraenesocidae, Familia
Muraenesox, Genus
Muraenidae, Familia
Murenes [France and Belgium], Familia
– synonym of Muraenidae, Familia
Mustelus, Genus
Mycteroperca, Genus
Myctophidae, Familia
Myctophoidei, Subordo
Myctophum, Genus
Myliobatidae, Familia
Myliobatis, Genus
Myoxocephalus, Genus
Myxine, Genus
Myxines [France and Belgium], Familia
– synonym of Myxinidae, Familia
Myxinidae, Familia
Myxiniformes, Ordo