774 articles
Helicoprion
Helicoprion, an extinct Permian eugeneodont cartilaginous fish (not a true shark) known from spiral tooth whorls embedded in the lower jaw; named by Karpinsky in 1899, resolved by 2013 CT scans of Idaho specimen IMNH 37899.
Hemibagrus nemurus
Hemibagrus nemurus, the Asian redtail catfish or baung (Bagrus nemurus, Mystus nemurus), is a large bagrid river catfish of the Mekong, Chao Phraya, Malay Peninsula, Sumatra, Java, and Borneo, reaching 65 cm, farmed commercially, IUCN Least Concern.
Hemiramphus brasiliensis
Hemiramphus brasiliensis, the ballyhoo halfbeak (formerly Esox brasiliensis), is a schooling Atlantic halfbeak fish used mainly as bait for sailfish and marlin; IUCN Least Concern, matures near 20 cm.
Herring
Herring (Clupea harengus, C. pallasii, C. harengus membras): small silvery schooling Clupeidae forage fish of the North Atlantic and North Pacific, historic staple of European fisheries, now managed under stock assessments; Atlantic herring overfished per 2024 assessment.
Heterobranchus bidorsalis
Heterobranchus bidorsalis, African giant catfish or eel-like fattyfin catfish, a clariid catfish described 1809 from the Nile, ranging Senegal to Ethiopia, reaching 1500 mm and 30 kg, farmed and hybridized with Clarias gariepinus.
Heterobranchus longifilis
Heterobranchus longifilis (vundu, Sampa), Valenciennes 1840, a large African airbreathing clariid catfish up to 150 cm and 55 kg, widespread from the Nile to West Africa, Least Concern, farmed and used in heteroclarias hybrids.
Heterotis niloticus
Heterotis niloticus, the African bonytongue or African arowana, is a large obligate air-breathing osteoglossiform fish native to Sahelo-Sudanese African river basins, introduced elsewhere, IUCN Least Concern, and used in fisheries and aquaculture.
Hippoglossoides platessoides
Hippoglossoides platessoides, the American plaice (also Canadian plaice, long rough dab), is a right-eyed North Atlantic flatfish of the family Pleuronectidae, living on soft bottoms from Labrador to Rhode Island and the eastern Atlantic, managed as a groundfish fishery.
Hippoglossus hippoglossus
Hippoglossus hippoglossus, the Atlantic halibut, is the world's largest flatfish, a right-eyed demersal predator of the North Atlantic. Distinguished from Pacific halibut (Hippoglossus stenolepis) by scale, fin, and body shape; US stock overfished with a 2055 rebuilding target.
Hippoglossus stenolepis
Hippoglossus stenolepis, the Pacific halibut, is a large right-eyed flatfish native to the North Pacific from Japan to Baja California, reaching over 500 pounds.
Holocephali
Holocephali, also known as holocephalans, is a subclass of cartilaginous fish containing the chimaeras, or ghost sharks, with upper jaws fused to the skull and a fossil record reaching back almost 360 million years.
Hoplerythrinus unitaeniatus
Hoplerythrinus unitaeniatus, the jeju or gold wolf fish (aimara), a South American trahira fish of the Erythrinidae that breathes air through a vascularized swimbladder across five major river basins.
Hoplias malabaricus
Hoplias malabaricus, the trahira, is a carnivorous freshwater fish widespread from northern to southern South America, known as a top predator important to artisanal fisheries.
Hoplosternum littorale
Hoplosternum littorale (brown hoplo, atipa, tamboatá), a callichthyid armored catfish from South America; air-breathing bubble-nest builder, up to 26.3 cm, invasive and established in Florida since 1995, valued food fish.
Hoplostethus mediterraneus
Hoplostethus mediterraneus, the Mediterranean slimehead or silver roughy (Cuvier, 1829), a benthopelagic Trachichthyidae fish of 100–1,463 m depth, circumtropical, IUCN Least Concern, trawl bycatch, lifespan about 11 years.
Hucho hucho
Hucho hucho, the huchen or Danube salmon (Salmo hucho, Linnaeus 1758), is a large Danube-endemic salmonid top predator reaching 150 cm and 52 kg; IUCN Endangered 2008, Vulnerable 2024, sustained largely by stocking.
Hucho taimen
Hucho taimen, the Siberian taimen, is the world's largest salmonid (up to 2 m, 100 kg), a Vulnerable predatory fish of northern Asia from the Urals to the Pacific, declining 30-95% across China, Kazakhstan, Mongolia, and Russia.
Hybodus
Hybodus is an extinct genus of hybodontiform shark, type species H. reticulatus from the Lower Jurassic of Lyme Regis; a wastebasket taxon of 2-3 m spined sharks from Triassic to Late Cretaceous.
Hydrocynus goliath
Hydrocynus goliath, the giant or goliath tigerfish, is a large piscivorous African freshwater fish (Alestidae) of the Congo basin and Lake Tanganyika, reaching 133 cm and 50 kg, IUCN Least Concern.
Hydrolycus scomberoides
Hydrolycus scomberoides, the payara (basionym Hydrocyon scomberoides Cuvier 1819), is a fanged piscivorous characiform fish of the Amazon basin, family Cynodontidae, IUCN Least Concern, max 117 cm TL and 17.8 kg.
Hyperoplus lanceolatus
Hyperoplus lanceolatus (Le Sauvage, 1824), greater sandeel or great sandeel, largest Ammodytidae sand lance of the NE Atlantic to 40 cm; dark snout spot, two palate teeth, non-protrusible upper jaw; COI barcoding cannot separate it from Ammodytes tobianus.
Hypophthalmichthys nobilis
Hypophthalmichthys nobilis, the bighead carp, a large East Asian filter-feeding cyprinid farmed worldwide and invasive in the Mississippi River basin; introduced to the US in 1973, listed injurious in 2011.
Hypostomus plecostomus
Hypostomus plecostomus, also known as the common pleco, is an armored suckermouth catfish native to the Guianas in northern South America, a popular algae-eating aquarium fish.
Ichthyology
Ichthyology is the branch of zoology devoted to the scientific study of fishes, covering their taxonomy, anatomy, behavior, ecology, and conservation; about 36,000 species are known.
Ichthys
Ichthys (ἰχθύς, Greek for fish), also called the Jesus fish, is an early Christian symbol of two intersecting arcs read as an acrostic for "Jesus Christ, Son of God, Savior", used from the second century in the Roman catacombs and revived on car emblems in the 1970s.
Ictalurus furcatus
Ictalurus furcatus, the blue catfish, is a large North American catfish native to the Mississippi, Missouri, Ohio, and Rio Grande basins and, since 1970s introductions in Virginia, invasive in the Chesapeake Bay.
Ilish (ইলিশ)
Ilish (ইলিশ), hilsa or Indian shad (Tenualosa ilisha), is the anadromous national fish of Bangladesh, a prized Bengali food fish; a US$2 billion fishery, overfished in parts, with Ganga restoration and 2026 India-to-Bangladesh exports.
Infection with infectious salmon anaemia virus
Infection with infectious salmon anaemia virus (ISAV, Isavirus salaris), a WOAH-listed orthomyxovirus disease of Atlantic salmon; avirulent HPR0 versus virulent HPRΔ variants, first outbreak Norway 1984, now in most salmon-farming countries.
Infectious haematopoietic necrosis
Infectious haematopoietic necrosis (IHN), caused by IHNV (Salmonid novirhabdovirus, Novirhabdoviridae), is a WOAH-notifiable rhabdovirus disease of salmonid fish, first seen in 1953 in Washington sockeye hatcheries, with fry mortality up to 90–95% at 8–14 °C.
Iridescent shark
Iridescent shark (Pangasianodon hypophthalmus, striped catfish, swai): a large Mekong-basin migratory catfish, IUCN Endangered in the wild, farmed at over a million tonnes yearly in Vietnam, and sold as an aquarium fish that outgrows home tanks.