774 articles
Milt
Milt is the sperm-containing seminal fluid of male fish, shed at spawning. Also called shirako in Japanese cuisine, it is used to fertilize farmed fish eggs, eaten as food, and processed into protamines for heparin overdose treatment.
Minnow
Minnow: true minnows are small freshwater fishes of the family Leuciscidae (Cypriniformes), also called shiners, chubs, and daces; used as bait fish, distinct from mosquitofish Gambusia and killifish mummichogs.
Mobula thurstoni
Mobula thurstoni (bentfin devil ray, Lloyd 1908), a mobulid ray of tropical and temperate seas worldwide, identified by double-curved pectoral fin margins; IUCN Critically Endangered since 2025 due to gill-plate fisheries.
Monopterus albus
Monopterus albus, the Asian swamp eel or rice-field eel (鳝鱼), is an air-breathing synbranchid fish of Asia, a major Chinese aquaculture species, a protogynous sex-reversing vertebrate, and a High-risk U.S. invasive established in Florida, Georgia, and Hawaii.
Moray eel
Moray eels (family Muraenidae), over 200 species of benthic predatory eels, are known for raptorial pharyngeal jaws that shoot forward to swallow prey, nocturnal crevice hunting, and cooperative hunting with groupers.
Mormyridae
Mormyridae (elephantfishes) are African freshwater Osteoglossiformes, about 240 species, that generate weak electric organ discharges for electrolocation and electrocommunication, with species-specific EOD waveforms and large cerebellums.
Morone chrysops
Morone chrysops, the white bass (bar blanc), a North American freshwater temperate bass of the Mississippi system; silvery schooling game fish, single tongue tooth patch, IUCN Least Concern, parent of hybrid striped bass.
Mosquitofish
Mosquitofish (Gambusia affinis) are small live-bearing fish of the southeastern United States, introduced worldwide for mosquito control and now among the world's worst invasive fish.
Mugil cephalus
Mugil cephalus, the flathead grey mullet or striped mullet, is a cosmopolitan euryhaline mugilid fish of coastal and estuarine waters, farmed for centuries, spawning at sea, and now shown by genetics to be a complex of at least 14 species.
Mugil curema
Mugil curema, the white mullet (also silver mullet, lisa blanca), is a mugilid fish of Atlantic and Pacific American coasts and the eastern Atlantic; a commercially important estuarine species later shown to be a complex of cryptic lineages.
Mugil liza
Mugil liza, the Lebranche mullet (tainha, liza), a grey mullet of the western Atlantic from Florida and the Caribbean to Argentina; catadromous, up to 80 cm, commercially fished and farmed, IUCN Data Deficient.
Mugilidae
Mugilidae, the grey mullets, sole family of Mugiliformes: coastal schooling fishes of tropical to temperate seas, about 26 genera and 78 species, revised to 25 genera after molecular phylogenies overturned morphology-based taxonomy.
Mullet (fish)
Mullet (fish): the grey mullets, family Mugilidae, coastal fishes of all tropical to temperate seas; detritus-feeding food fish including Mugil cephalus, with molecular phylogeny showing seven lineages and cryptic species.
Mullidae
Mullidae, goatfishes (rougets, surmullets), a family of marine perciform fish with two chemosensory chin barbels, two separated dorsal fins, 24 vertebrae; 101 species in 6 genera, tropical to temperate seas, valued food fish.
Mullus surmuletus
Mullus surmuletus, the striped red mullet or surmullet, is a goatfish (Mullidae) of the eastern Atlantic and Mediterranean, demersal at 5-409 m, up to 40 cm and 11 years, fished heavily, IUCN Least Concern.
Muraena helena
Muraena helena, the Mediterranean moray (Murène commune), is a moray eel of the Muraenidae from the Mediterranean and eastern Atlantic, a nocturnal rocky-reef predator of cephalopods and fish, reaching about 150 cm and 38 years.
Muskellunge
Muskellunge (Esox masquinongy), also musky or muskie, largest pike-family fish of eastern North America; trophy coolwater predator, 'fish of 10,000 casts', tiger muskie hybrid with northern pike.
Mustelus mustelus
Mustelus mustelus, the common smoothhound (emissole lisse, musola), is a triakid shark of the Mediterranean and east Atlantic to South Africa; IUCN Endangered A2bd, viviparous, 176 cm max, CITES Appendix II from 2027.
Myliobatiformes
Myliobatiformes, the stingray order of Batoidea, includes stingrays, eagle rays, cownose rays, and manta rays; 234 species with fused pectoral fins, whip-like tails, and stinging spines.
Myoxocephalus scorpius
Myoxocephalus scorpius, the shorthorn sculpin (basionym Cottus scorpius, Linnaeus 1758), is a North Atlantic and Arctic demersal sculpin of the family Cottidae, reaching 78 cm, spawning December to March with male-guarded eggs, and used as an Arctic pollution sentinel species.
Myxine glutinosa
Myxine glutinosa, the Atlantic hagfish (Atlantic hagfish, myxine du nord), is a jawless, slime-producing North Atlantic fish described by Linnaeus in 1758, living on muddy bottoms at 20-1200 m and listed as Least Concern.
Myzopsetta ferruginea
Myzopsetta ferruginea, the yellowtail flounder (formerly Limanda ferruginea), is a righteye flatfish of the Northwest Atlantic from southern Labrador to Chesapeake Bay; a commercial species listed IUCN Vulnerable, reaching 64 cm and 12 years of age.
Naucrates ductor
Naucrates ductor, the pilotfish (pez piloto, poisson pilote), a circumtropical carangid fish that accompanies sharks, rays, turtles, and ships, feeding on scraps, parasites, and excrement; IUCN Least Concern.
Needlefish
Needlefish (Belonidae) are slender surface predators with a full, toothed beak of equal jaws, from 6-7 cm freshwater forms to 2 m marine species, worldwide in tropical and temperate waters.
Nemipterus japonicus
Nemipterus japonicus, the Japanese threadfin bream (Japanese threadfin-bream), is an Indo-West Pacific demersal Nemipteridae fish, 5-80 m depth, to about 32 cm, Least Concern, with cryptic Indian Ocean and western Pacific lineages and major trawl fisheries.
Neoceratodus forsteri
Neoceratodus forsteri, the Australian or Queensland lungfish, is a single-lunged lobe-finned fish of the Burnett and Mary rivers, Queensland; a vulnerable living fossil and the closest living relative of tetrapods.
Neogobius melanostomus
Neogobius melanostomus, the round goby, a Ponto-Caspian gobiid fish invasive in the Great Lakes, Baltic Sea, and major European rivers; ballast-water introductions since 1990, mussel and fish-egg predation, and temperature-dependent salinity tolerance.
Neon tetra
Neon tetra (Paracheirodon innesi, formerly Hyphessobrycon innesi), a 2.5 cm Amazonian characid fish with a blue-red iridescent stripe; IUCN Least Concern, mostly captive-bred in Asia, one of the most popular aquarium fish.
Nile perch
Nile perch (Lates niloticus), a large African predatory fish up to 2 m and 200 kg, native to the Nilo-Sudan region; its 1950s-60s introduction to Lake Victoria caused mass haplochromine extinctions but created a major export fishery.
Ningyo (人魚)
Ningyo (人魚) is the Japanese human-fish of folklore, first recorded in the 937 Wamyō ruijūshō. Unlike Western mermaids, it was an ill omen in medieval Japan, later auspicious, inspiring Yao Bikuni legends and manufactured mummies exported worldwide.