-
Liparidae – Sea snails
Family, Bony fish (Actinopterygii), Marine
-
Lophiidae – Anglerfishes
Family, Bony fish (Actinopterygii), Marine
-
Lotidae
Family, Bony fish (Actinopterygii), Marine, terrestrial
-
Luvaridae – Luvar
Family, Bony fish (Actinopterygii), Marine
-
Macrouridae – Grenadiers
Family, Bony fish (Actinopterygii), Marine, terrestrial
Grenadiers or rattails
-
Melamphaidae – Bigscale fishes
Family, Bony fish (Actinopterygii), Marine
-
Melanocetidae
Family, Bony fish (Actinopterygii), Marine
-
Melanonidae – Pelagic cods
Family, Bony fish (Actinopterygii), Marine
-
Merlucciidae – Hakes
Family, Bony fish (Actinopterygii), Marine
-
Microstomatidae
Family, Bony fish (Actinopterygii), Marine
-
Mirapinnidae – Mirapinnids
Family, Bony fish (Actinopterygii), Marine
-
Molidae – Sunfishes
Family, Bony fish (Actinopterygii), Marine
-
Moridae – Deep-sea cods
Family, Bony fish (Actinopterygii), Marine
-
Moronidae
Family, Bony fish (Actinopterygii), Marine, terrestrial
-
Mugilidae
Family, Bony fish (Actinopterygii), Marine, terrestrial
-
Mullidae
Family, Bony fish (Actinopterygii), Marine
-
Muraenidae
Family, Bony fish (Actinopterygii), Marine
-
Myctophidae – Lanternfishes
Family, Bony fish (Actinopterygii), Marine
-
Myliobatidae
Family, Cartilagenous fish (Chondrichthyes), Marine
-
Myxinidae – Hagfishes
Family, Jawless fish (Agnatha), Marine