Table of Contents

Fish name etymologies are published in a series of pages arranged in phylogenetic sequence. Each linked page below may comprise an entire order, individual families within an order, or a selection of genera (in alphabetical order) from an exceptionally diverse subfamily or subfamily.

updated/revised 22 March 2017

Class MYXINI
Order MYXINIFORMES Hagfishes
Family MYXINIDAE    (6 genera • 81 species)
Subfamily RUBICUNDINAE
Subfamily EPTATRETINAE
Subfamily MYXININAE

Class PETROMYZONTIDA
Order PETROMYZONTIFORMES Lampreys   (3 families • 11 genera/subgenera • 45 species)
Family PETROMYZONTIDAE Northern Lampreys   (9 genera/subgenera • 41 species)
Subfamily PETROMYZONTINAE
Subfamily LAMPRETINAE
Family GEOTRIIDAE Southern Lamprey   (monotypic)
Family MORDACIIDAE Southern Topeyed Lampreys   (1 genus • 3 species)

Class CHONDRICHTHYES Cartilaginous Fishes
chondros, cartilage; ichthos, fish, i.e., fishes (chimaeras, sharks, skates, rays) with cartilaginous skeleton

Subclass HOLOCEPHALI
holos, whole; cephalus, head, referring to how one gill opening gives heads an undivided appearance (compared to 5-7 gill openings of Subclass Elasmobranchii)

Order CHIMAERIFORMES Chimaeras   (3 families · 6 genera · 52 species)
Family CALLORHINCHIDAE Plownose Chimaeras   (1 genus • 3 species)
Family CHIMAERIDAE Shortnose Chimaeras   (2 genera • 41 species)
Family RHINOCHIMAERIDAE Longnose Chimaeras or Ratfishes   (3 genera • 8 species)

Class CHONDRICHTHYES Subclass ELASMOBRANCHII
elasmos, plate; branchos, gill, referring to platelike interbranchial septa (i.e., tissue layer separating two halves of gill)

Infraclass EUSELACHII
eu-, true, good or original; selachos, a cartilaginous fish, including all elasmobranchs that have an anal fin (secondarily lost in many living forms) and two dorsal fins each with an anterior, cylindroconical spine of enameloid and dentine supported by the fin skeleton (spines lost in most living neoselachians; the first dorsal fin is absent in a few living sharks, and one or both dorsals are absent in many rays)

Division NEOSELACHII
neo-, new or modern; selachos, a cartilaginous fish, including all living sharks and rays and certain Mesozoic sharks, including palaeospinacids (Palaeospinax and Synechodus) and possibly orthacodonts and anacoracids

Subdivision SELACHII (“The Sharks”)
selachos, a cartilaginous fish, comprising the sharks
(9 orders • 34 families • 108 genera/subgenera • 523 species/subspecies)

Order HETERODONTIFORMES Bullhead Sharks
Family HETERODONTIDAE   (1 genus • 9 species)

Order ORECTOLOBIFORMES Carpet Sharks   (7 families • 13 genera • 45 species)
Family PARASCYLLIIDAE Collared Carpet Sharks   (2 genera • 8 species)
Family BRACHAELURIDAE Blind Sharks   (1 genus • 2 species)
Family ORECTOLOBIDAE Wobbegongs   (3 genera • 12 species)
Family HEMISCYLLIIDAE Bamboo Sharks   (2 genera • 17 species)
Family STEGOSTOMATIDAE Zebra Shark   (monotypic)
Family GINGLYMOSTOMATIDAE Nurse Sharks   (3 genera • 4 species)
Family RHINCODONTIDAE Whale Shark   (monotypic)

Order LAMNIFORMES Mackerel Sharks   (7 families • 10 genera • 16 species)
Family ODONTASPIDIDAE Sand Tiger Sharks   (2 genera • 4 species)
Family MITSUKURINIDAE Goblin Shark   (monotypic)
Family PSEUDOCARCHARIIDAE Crocodile Shark   (monotypic)
Family MEGACHASMIDAE Megamouth Shark   (monotypic)
Family ALOPIIDAE Thresher Sharks   (1 genus • 3 species)
Family CETORHINIDAE Basking Shark   (monotypic)
Family LAMNIDAE Mackerel Sharks   (3 genera • 5 species)

Order CARCHARHINIFORMES Ground Sharks   (8 families • 53 genera/subgenera • 287 species/subspecies)
Family SCYLIORHINIDAE Cat Sharks    (17 genera • 155 species)
Family PROSCYLLIIDAE Finback Cat Sharks   (3 genera • 7 species)
Family PSEUDOTRIAKIDAE False Cat Sharks   (3 genera • 4 species)
Family LEPTOCHARIIDAE Barbled Hound Shark   (monotypic)
Family TRIAKIDAE Hound Sharks   (9 genera • 47 species/subspecies)
Subfamily TRIAKINAE Hound Sharks
Subfamily GALEORHININAE School Sharks
Family HEMIGALEIDAE Weasel Sharks   (4 genera • 8 species)
Family CARCHARHINIDAE Requiem Sharks   (12 genera • 56 species)
Family SPHYRNIDAE Hammerhead Sharks   (4 genera/subgenera • 9 species)

Order HEXANCHIFORMES   (2 families • 4 genera • 6 species)
Family CHLAMYDOSELACHIDAE Friled Sharks   (1 genus • 2 species)
Family HEXANCHIDAE Cow Sharks   (3 genera • 4 species)

Order ECHINORHINIFORMES Bramble Sharks
Family ECHINORHINIDAE   (1 genus • 2 species)

Order SQUALIFORMES Dogfish Sharks   (6 families • 23 genera/subgenera • 129 species/subspecies)
Family CENTROPHORIDAE Gulper Sharks   (2 genera • 16 species/subspecies)
Family ETMOPTERIDAE Lantern Sharks   (4 genera • 48 species)
Family SOMNIOSIDAE Sleeper Sharks   (7 genera/subgenera • 17 species)
Family OXYNOTIDAE Rough Sharks   (1 genus • 5 species)
Family DALATIIDAE Kitefin Sharks   (7 genera • 9 species)
Family SQUALIDAE Dogfish Sharks   (2 genera • 34 species/subspecies)

Order SQUATINIFORMES Angel Sharks
Family SQUATINIDAE   (1 genus • 21 species)

Order PRISTIOPHORIFORMES Saw Sharks
Family PRISTIOPHORIDAE   (2 genera • 8 species)

Division NEOSELACHII Subdivision BATOIDES (“The Rays”)
-oides, having the form of: batis, Greek for a flat fish, usually applied to a skate or ray
(4 orders • 26 families • 105 genera/subgenera • 647 species/subspecies)

Order TORPEDINIFORMES Electric Rays   (5 families • 15 genera • 64 species)
Family PLATYRHINIDAE Fanrays   (2 genera • 5 species)
Family TORPEDINIDAE Electric Rays  (2 genera • 18 species)
Family HYPNIDAE Coffin Ray  (monotypic)
Family NARCINIDAE Numbfishes   (5 genera • 31 species) 
Family NARKIDAE Sleeper Rays  (5 genera • 9 species)

Order RHINOPRISTIFORMES Guitarfishes and Sawfishes    (5 families • 12 genera • 64 species)
Family TRYGONORRHINIDAE Banjo Rays   (3 genera • 8 species)
Family RHINOBATIDAE Guitarfishes   (3 genera • 32 species)
Family RHINIDAE Wedgefishes   (3 genera • 10 species)
Family GLAUCOSTEGIDAE Giant Guitarfishes   (1 genus • 9 species)
Family PRISTIDAE Sawfishes   (2 genera • 5 species)

Order RAJIFORMES Skates   (4 families • 39 genera/subgenera • 296 species/subspecies)
Family ARHYNCHOBATIDAE Softnose Skates   (14 genera/subgenera • 105 species)
Family GURGESIELLIDAE Pygmy Skates   (3 genera • 19 species)
Family RAJIDAE Skates   (17 genera • 158 species/subspecies)
Family ANACANTHOBATIDAE Legskates   (5 genera • 14 species)

Order MYLIOBATIFORMES Stingrays   (12 families • 39 genera • 223 species)
Family ZANOBATIDAE Panrays   (1 genus • 2 species)
Family PLESIOBATIDAE Giant Stingaree   (monotypic)
Family UROLOPHIDAE Stingarees   (3 genera • 28 species)
Family HEXATRYGONIDAE Sixgill Stingray   (monotypic)
Family DASYATIDAE Stingrays   (19 genera • 90 species)
Subfamily DASYATINAE   (8 genera • 34 species)
Subfamily NEOTRYGONINAE   (2 genera • 12 species)
Subfamily UROGYMNINAE   (7 genera • 38 species)
Subfamily HYPOLOPHINAE   (2 genera • 6 species)
Family POTAMOTRYGONIDAE Neotropical Stingrays   (5 genera • 34 species)
Subfamily STYRACURINAE   (1 genus • 2 species)
Subfamily POTAMOTRYGONINAE   (4 genera • 32 species)
Family GYMNURIDAE Butterfly Rays    (1 genus • 11 species)
Family UROTRYGONIDAE Round Rays   (2 genera • 17 species)

Family AETOBATIDAE Pelagic Eagle Rays   (1 genus • 5 species)
Family MYLIOBATIDAE Eagle Rays   (2 genera • 18 species)
Family RHINOPTERIDAE Cownose Rays   (1 genus • 8 species)
Family MOBULIDAE Devilrays   (2 genera • 8 species)

Class OSTEICHTHYES Bony Fishes and Tetrapods
osteo-, bone; ichthys, fish, i.e., fishes (and their tetrapod relatives) with skeletons (at least in part) made from bone

Subclass SARCOPTERYGII Lobe-finned Fishes and Tetrapods
sarco-, flesh; pteron, fin or wing, fishes with fleshy, lobed fins (a clade that now includes all four-limbed vertebrates), as opposed to the ray-finned fishes that characterize the subclass Actinopterygii

Infraclass ACTINISTIA
etymology not explained, perhaps actino-, ray, possibly referring to single fin ray to each basal bone; –ista, a signifying agent, “one with a ray”

Order COELACANTHIFORMES Coelacanths
Family LATIMERIIDAE Coelacanths   (1 genus • 2 species)

Subclass SARCOPTERYGII Infraclass DIPNOMORPHA
di-, two and pneuma, breath, i.e., double breathing, having both external and internal nostrils; morpha, form or shape

Order CERATODONTIFORMES Lungfishes   (3 extant families • 3 genera • 9 species/subspecies)
Family NEOCERATODONTIDAE Australian Lungfish   (monotypic)
Family LEPIDOSIRENIDAE South American Lungfish   (monotypic)
Family PROTOPTERIDAE African Lungfishes   (1 genus • 7 species/subspecies)

Class OSTEICHTHYES Subclass ACTINOPTERYGII Ray-finned Fishes
actino-, ray; pteron, fin or wing, i.e., fishes with fins of webbed skin supported by bony or horny spines (“rays”), as opposed to the fleshy, lobed fins that characterize the subclass Sarcopterygii

Infraclass CLADISTIA
etymology not explained, perhaps clado, branch; –ista, a signifying agent, i.e., “one that branches,” possibly referring to basally branching rays of polypterids (bichirs)

Order POLYPTERIFORMES Bichirs
Family POLYPTERIDAE   (2 genera • 19 species/subspecies)

Subclass ACTINOPTERYGII Infraclass CHONDROSTEI
chondros, cartilage; osteo, bone, being primarily cartilaginous fishes that show some ossification

Order ACIPENSERIFORMES   (2 families • 6 genera • 32 species/subspecies)
Family ACIPENSERIDAE Sturgeons   (4 genera • 30 species/subspecies)
Subfamily ACIPENSERINAE       
Subfamily SCAPHIRHYNCHINAE       
Subfamily PSEUDOSCAPHIRHYNCHINAE       
Subfamily HUSINAE
Family POLYODONTIDAE Paddlefishes   (2 genera • 2 species)

Subclass ACTINOPTERYGII [unranked taxon] NEOPTERYGII
neo-, new or modern; pterus, fin or wing, presumably referring to the “newness” or modernity of their rayed fins

Infraclass HOLOSTEI
holos, whole or entire; osteus, bone, referring to highly ossified skeleton in most taxa (a thin layer of bone covers a mostly cartilaginous skeleton in bowfins, Amiiformes)

Division GINGLYMODI
ginglymos, hinge; –oides, having the form of, referring to hinge-like joints of the vertebrae

Order LEPISOSTEIFORMES Gars
Family LEPISOSTEIDAE   (2 genera • 7 species)

Division HALECOMORPHI
haleco, shad or herring; morpha, form or shape; Edward Drinker Cope, who proposed the taxon, apparently believed that Amiiformes had more in common with shads and herrings (Clupeiformes) than with gars (Lepisosteiformes) based on the presence of a gular plate, which reappears in the herring-like family Elopidae (Elopiformes)

Order AMIIFORMES Bowfins
Family AMIIDAE   (one extant genus and species)

[unranked taxon] NEOPTERYGII Division TELEOSTEOMORPHA
teleosteo, teleost, proposed as a clade to include all extant teleostean fishes and all fossil taxa more closely related to extant teleosteans than to any other extant group of fishes; morpha, form or shape

Subdivision TELEOSTEI
teleos, perfect or complete; osteus, bone, possibly referring to entire skeletons comprised completely of true bone (rather than cartilage), but perhaps also referring to their evolutionary position as the most advanced of living fishes

Cohort ELOPOMORPHA

Order ELOPIFORMES   (2 families • 2 genera • 9 species)
Family ELOPIDAE Tenpounders   (1 genus • 7 species)
Family MEGALOPIDAE Tarpons   (1 genus • 2 species)

Order ALBULIFORMES Bonefishes
Family ALBULIDAE   (3 genera • 13 species)
Subfamily ALBULINAE
Subfamily PTEROTHRISSINAE

Order NOTACANTHIFORMES   (2 families • 8 genera/subgenera • 27 species)
Family HALOSAURIDAE Halosaurs   (4 genera/subgenera • 16 species)
Family NOTACANTHIDAE Deep-sea Spiny Eels   (4 genera • 11 species)

Order ANGUILLIFORMES Eels   (19 families • 166 genera/subgenera • 969 species/subspecies)
Family PROTANGUILLIDAE Primitive Cave Eel   (monotypic)
+ Family SYNAPHOBRANCHIDAE Cutthroat Eels   (12 genera • 39 species)
Subfamily SIMENCHELYINAE Pugnose Snubnose Eel
Subfamily ILYOPHINAE Arrowtooth Eels or Mustard Eels
Subfamily SYNAPHOBRANCHINAE Cutthroat Eels         
+ Family HETERENCHELYIDAE Mud Eels   (2 genera • 8 species)
+ Family MYROCONGRIDAE Myroconger Eels   (1 genus • 5 species)
+ Family MURAENIDAE Moray Eels   (19 genera/subgenera • 201 species)
Subfamily UROPTERYGIINAE  

Subfamily MURAENINAE
+ Family CHLOPSIDAE False Morays   (8 genera • 25 species)
+ Family DERICHTHYIDAE Longneck Eels and Shorttail Eels   (3 genera • 11 species) 
Family OPHICHTHIDAE Snake Eels and Worm Eels   (66 genera/subgenera • 338 species)
Subfamily OPHICHTHINAE Snake Eels
Subfamily MYROPHINAE Worm Eels
Family MURAENESOCIDAE Pike Congers   (6 genera • 15 species)
+ Family NETTASTOMATIDAE Duckbill Eels   (6 genera • 46 species)
+ Family CONGRIDAE Conger Eels   (29 genera • 198 species)
Subfamily CONGRINAE Conger Eels
Subfamily HETEROCONGRINAE Garden Eels
Subfamily BATHYMYRINAE
+ Family MORINGUIDAE Spaghetti Eels   (2 genera • 15 species)
+ Family CYEMATIDAE Bobtail Snipe Eels   (2 genera • 2 species)
+ Family MONOGNATHIDAE Onejaw Gulpers   (1 genus • 15 species)
+ Family SACCOPHARYNGIDAE Swallowers   (1 genus • 10 species)
+ Family EURYPHARYNGIDAE Gulper or Pelican Eel   (monotypic)
+ Family NEMICHTHYIDAE Snipe Eels   (3 genera • 9 species)
+ Family SERRIVOMERIDAE Sawtooth Eels   (2 genera • 10 species)
+ Family ANGUILLIDAE Freshwater Eels   (1 genus • 20 species/subspecies)

Cohort OSTEOGLOSSOMORPHA
osteo-, bone and glossum, tongue, referring to toothed tongue; morpha, form or shape

Order HIODONTIFORMES Mooneyes
Family HIODONTIDAE   (1 genus • 2 species)

Order OSTEOGLOSSIFORMES   (6 families • 32 genera/subgenera • 252 species/subspecies)
Family PANTODONTIDAE Freshwater Butterflyfish   (monotypic)
Family OSTEOGLOSSIDAE Bonytongues   (3 genera/subgenera • 6 species)
Family ARAPAIMIDAE Arapaimas   (2 genera • 5 species)
Family NOTOPTERIDAE Featherfin Knifefishes   (4 genera • 10 species)
Subfamily NOTOPTERINAE
Subfamily XENOMYSTINAE
Family MORMYRIDAE Elephantfishes   (21 genera • 229 species/subspecies)
Subfamily MORMYRINAE
Subfamily PETROCEPHALINAE
Family GYMNARCHIDAE Aba   (monotypic)

Cohort OTOCEPHALA
oto-, referring to otophysic (hearing) connection between swim bladder and inner ear in most members; cephala, head, perhaps used here to delineate a “crown group” of euteleostean fishes

Superorder CLUPEOMORPHA
clupea, a herring; morpha, form or shape, i.e., herring-like fishes

Order CLUPEIFORMES   (5 families • 89 genera/subgenera • 436 species/subspecies)
Family DENTICIPITIDAE Denticle Herring   (one extant species)
+ Family PRISTIGASTERIDAE Longfin Herrings   (9 genera • 39 species)
Subfamily PELLONINAE

Subfamily PRISTIGASTERINAE
+ Family ENGRAULIDAE Anchovies   (18 genera • 156 species/subspecies)
Subfamily COILIINAE

Subfamily ENGRAULINAE
+ Family CHIROCENTRIDAE Wolf Herrings   (1 genus • 2 species)
Family CLUPEIDAE Herrings   (60 genera/subgenera • 238 species/subspecies)
Subfamily DUSSUMIERIINAE Round Herrings   (4 genera • 19 species)
Subfamily EHIRAVINAE    (8 genera • 19 species)
Subfamily PELLONULINAE Freshwater Herrings   (16 genera • 34 species)
Subfamily CLUPEINAE Herrings, Sardines and Sprats   (17 genera/subgenera • 86 species/subspecies)
Subfamily ALOSINAE Shads   (8 genera/subgenera • 56 species/subspecies)
Subfamily DOROSOMATINAE Gizzard Shads   (7 genera/subgenera • 24 species)      

Superorder ALEPOCEPHALI
Order ALEPOCEPHALIFORMES Slickheads   (3 families • 33 genera • 142 species/subspecies)
Family PLATYTROCTIDAE Tubeshoulders   (13 genera • 40 species)
Family BATHYLACONIDAE   (1 genus • 3 species)
Family ALEPOCEPHALIDAE Slickheads   (19 genera • 99 species/subspecies)

Superorder OSTARIOPHYSI
ostar, small bone; physa, bladder, referring to Weberian apparatus, a complex of modified vertebrae and ligaments that connect the gas bladder to the inner ear (except for Series Anotophysi)

Series ANOTOPHYSI
an-, without; oto-, ear; physa, bladder, referring to lack of Weberian apparatus; instead, anotophysans possess a primitive homolog consisting of three modified anterior vertebrae associated with cephalic rib bones

Order GONORYNCHIFORMES   (4 families • 7 genera • 37 species)
Family CHANIDAE Milkfishes   (one extant species)
Family GONORYNCHIDAE Beaked Sandfishes   (1 genus • 5 species)
Family KNERIIDAE Knerias   (4 genera • 30 species)
Family PHRACTOLAEMIDAE Snake Mudhead   (monotypic)

Series OTOPHYSI
oto-, ear; physa, bladder, referring to Weberian apparatus, a complex of modified vertebrae and ligaments that connect gas bladder to inner ear, giving otophysans the most sensitive hearing among fishes 

Order CYPRINIFORMES   (13 families • 510 genera/subgenera • 4,583 species/subspecies)
Family CYPRINIDAE Carps and Minnows   (379 genera/subgenera • 3,243 species/subspecies)
Subfamily DANIONINAE   (41 genera • 354 species)
Subfamily CYPRININAE   (154 genera/subgenera • 1,670 species/subspecies)
AcrossocheilusEpalzeorhynchos

FoliferLuciocyprinus
MekonginaPuntius
QianlabeoXenobarbus
Subfamily LEUCISCINAE (Old World)   (42 genera/subgenera • 363 species/subspecies)
Subfamily LEUCISCINAE (New World)   (60 genera/subgenera • 374 species/subspecies)
Subfamily LEPTOBARBINAE   (1 genus • 5 species)
+ Subfamily ACHEILOGNATHINAE Bitterlings   (5 genera • 82 species/subspecies)
+ Subfamily GOBIONINAE Gudgeons   (30 genera/subgenera • 230 species/subspecies)
+ Subfamily TINCINAE Tench   (monotypic)
Subfamily XENOCYPRIDINAE   (45 genera • 164 species/subspecies)
Family PSILORHYCHIDAE Mountain Carps   (1 genus • 29 species)
+ Family GYRINOCHEILIDAE Algae Eaters   (1 genus • 3 species)
+ Family CATOSTOMIDAE Suckers   (14 genera/subgenera • 95 species/subspecies)
Subfamily MYXOCYPRININAE
Subfamily CYCLEPTINAE
Subfamily ICTIOBINAE
Subfamily CATOSTOMINAE
Family BOTIIDAE Botia Loaches   (8 genera • 59 species)
Subfamily LEPTOBOTIINAE
Subfamily BOTIINAE
+ Family VAILLANTELLIDAE Longfin Loaches   (1 genus • 3 species)
+ Family COBITIDAE Spined Loaches   (21 genera/subgenera • 204 species/subspecies)
Family BALITORIDAE Hillstream or River Loaches   (15 genera • 100 species/subspecies)
+ Family GASTROMYZONTIDAE Sucker Loaches   (20 genera/subgenera • 150 species)
+ Family BARBUCCIDAE Fire-eyed Loaches  (1 genus • 2 species)
+ Family ELLOPOSTOMATIDAE Squarehead Loaches  (1 genus • 2 species)
+ Family SERPENTICOBITIDAE Snake Loaches   (1 genus • 3 species)
Family NEMACHEILIDAE Stone Loaches   (47 genera • 690 species/subspecies)

Order CHARACIFORMES   (23 families • 284 genera/subgenera • 2,158 species/subspecies)
Family DISTICHODONTIDAE   (16 genera • 103 species/subspecies)
+ Family CITHARINIDAE Lutefishes   (3 genera • 10 species/subspecies)
+ Family CRENUCHIDAE South American Darters  ( 12 genera • 95 species)  
Subfamily CRENUCHINAE
Subfamily CHARACIDIINAE
+ Family ALESTIDAE African Tetras   (20 genera • 121 species/subspecies)
+ Famliy HEPSETIDAE African Pikes   (1 genus • 6 species)
Family ERYTHRINIDAE Trahiras   (3 genera • 18 species)
+ Family PARODONTIDAE   (3 genera • 32 species)
+ Family CYNODONTIDAE Dogtooth Tetras   (3 genera • 8 species)
+ Family SERRASALMIDAE Pacus and Piranhas   (16 genera • 92 species)
+ Family HEMIODONTIDAE Halftooths   (5 genera • 32 species/subspecies)
Subfamily ANODONTINAE        
Subfamily HEMIODONTINAE
+ Family ANOSTOMIDAE Toothed Headstanders   (15 genera • 155 species/subspecies)
+ Family CHILODONTIDAE Headstanders   (2 genera • 8 species)
Family CURIMATIDAE Toothless Characiforms   (8 genera • 108 species)
+ Family PROCHILODONTIDAE Bocachicos   (3 genera • 21 species)
+
Family LEBIASINIDAE Pencilfishes   (6 genera • 77 species/subspecies)
Subfamily LEBIASININAE        

Subfamily PYRRHULININAE
+ Family CTENOLUCIIDAE Pike-Characids   (2 genera • 7 species)
+ Family ACESTRORHYNCHIDAE   (7 genera • 26 species)
Subfamily ACESTRORHYNCHINAE Smallscale Pike Characins
Subfamily HETEROCHARACINAE
Subfamily ROESTINAE Biting Tetras
Family CHARACIDAE Characins   (142 genera/subgenera • 1,122 species/subspecies)
Subfamily STETHAPRIONINAE Silver Dollar Tetras   (6 genera • 17 species)
+ Subfamily RHOADSIINAE   (5 genera • 29 species)
+ Subfamily CHARACINAE    (11 genera • 89 species)

+ Subfamily TETRAGONOPTERINAE   (8 genera/subgenera • 196 species/subspecies) 
+ Subfamily APHYOCHARACINAE    (9 genera • 22 species) 
+ Subfamily APHYODITEINAE   (8 genera • 20 species) 
Subfamily CHEIRODONTINAE   (18 genera • 69 species)
+ Subfamily GYMNOCHARACINAE   (6 genera • 13 species) 
+ Subfamily PRISTELLINAE  (14 genera • 328 species/species)
Subfamily STEVARDIINAE   (44 genera • 325 species)   
+ Subfamily Incertae sedis   (13 genera • 14 species)  
Family IGUANODECTIDAE   (4 genera/subgenera • 32 species)  
+ Family TRIPORTHEIDAE Keeled Characins   (5 genera • 21 species)   
Subfamily TRIPORTHEINAE
Subfamily AGONIATINAE
Subfamily CLUPEACHARACINAE
+
Family BRYCONIDAE   (4 genera • 50 species)
Subfamily BRYCONINAE
Subfamily SALMININAE
+ Family CHALCEIDAE   (1 genus • 5 species)  
+ Family GASTEROPELECIDAE Freshwater Hatchetfishes   (3 genera • 9 species)

Order SILURIFORMES Catfishes   (41 families • 505 genera/subgenera • 3,801 species/subspecies)
Family DIPLOMYSTIDAE Velvet Catfishes   (2 genera • 7 species)
+ Family CETOPSIDAE Whale Catfishes   (5 genera • 42 species)
Subfamily HELOGENINAE
Subfamily CETOPSINAE
+ Family TRICHOMYCTERIDAE Pencil Catfishes   (41 genera • 297 species)
Subfamily COPIONODONTINAE
Subfamily TRICHOGENINAE
Subfamily TRICHOMYCTERINAE
Subfamily VANDELLIINAE
Subfamily TRICHOGENINAE
Subfamily STEGOPHILINAE
Subfamily TRIDENTINAE
Subfamily GLANAPTERYGINAE
Subfamily SARCOGLANIDINAE
+ Family NEMATOGENYIDAE Mountain Catfishes   (1 extant species)
Family CALLICHTHYIDAE Armored Catfishes   (8 genera • 214 species)
Subfamily CALLICHTHYINAE
Subfamily CORYDORADINAE Cory Cats
+ Family SCOLOPLACIDAE Spiny Dwarf Catfishes   (1 genus • 6 species)
+ Family ASTROBLEPIDAE Climbing Catfishes   (1 genus • 81 species)
Family LORICARIIDAE Suckermouth Armored Catfishes   (107 genera • 933 species)
Subfamily LITHOGENINAE Climbing Armored Catfishes   (1 genus • 3 species)
Subfamily NEOPLECOSTOMINAE    (8 genera • 59 species)
Subfamily HYPOPTOPOMATINAE Cascudinhos    (10 genera • 51 species)

Subfamily OTOTHYRINAE    (13 genera • 106 species)
Subfamily LORICARIINAE    (30 genera • 239 species)
Subfamily HYPOSTOMINAE    (42 genera/subgenera • 462 species)
+ Subfamily RHINELEPINAE    (3 genera • 6 species)

+ Subfamily DELTURINAE    (2 genera • 7 species)
Family SILURIDAE Sheatfishes   (13 genera • 100 species)
+ Family KRYPTOGLANIDAE Indian Cave Catfish   (monotypic)
+ Family AUSTROGLANIDIDAE Rock Catfishes   (1 genus • 3 species)
+ Family PANGASIIDAE Shark Catfishes   (5 genera/subgenera • 28 species)
+ Family CHACIDAE Frogmouth Catfishes   (1 genus • 4 species)
+ Family PLOTOSIDAE Eeltail Catfishes   (10 genera  • 41 species)
Family RITIDAE   (2 genera  • 14 species)
+ Family AILIIDAE Asian Butter Catfishes   (7 genera  • 25 species)
+ Family HORABAGRIDAE Sun or Imperial Catfishes   (4 genera • 11 species)
+ Family BAGRIDAE Naked or Bagrid Catfishes   (17 genera • 204 species)
Family AKYSIDAE Stream Catfishes   (5 genera • 57 species)
Subfamily AKYSINAE
Subfamily PARAKYSINAE
+ Family AMBLYCIPITIDAE Torrent Catfishes   (4 genera • 40 species)
+ Family SISORIDAE Hillstream Catfishes   (23 genera • 273 species)
Subfamily SISORINAE
Subfamily GLYPTOSTERNINAE
+ Family AMPHILIIDAE Loach Catfishes   (13 genera • 99 species)
Subfamily AMPHILIINAE
Subfamily LEPTOGLANIDINAE Sand Catlets
Subfamily DOUMEINAE
Family MALAPTERURIDAE Electric Catfishes   (2 genera • 19 species)
+ Family MOCHOKIDAE Squeaker or Upside-down Catfishes   (9 genera • 211 species)
Subfamily CHILOGLANIDINAE
Subfamily MOCHOKINAE
+ Family SCHILBEIDAE African Butter Catfishes   (5 genera • 33 species)
+ Family AUCHENOGLANIDIDAE Giraffe Catfishes  (3 genera • 26 species)
+ Family CLAROTEIDAE Grunter Catfishes   (12 genera/subgenera • 65 species)
+ Family LACANTUNIIDAE Chiapas Catfish   (monotypic)
Family CLARIIDAE Airbreathing Catfishes   (20 genera/subgenera • 120 species)
+ Family HETEROPNEUSTIDAE Airsac Catfishes   (1 genus • 4 species)
+ Family ANCHARIIDAE Madagascar Catfishes   (2 genera • 6 species)
+ Family ARIIDAE Sea Catfishes   (32 genera/subgenera • 148 species)
Subfamily GALEICHTHYINAE
Subfamily ARIINAE
Subfamily BAGREINAE
Family ASPREDINIDAE Banjo Catfishes   (13 genera • 44 species)
+ Family DORADIDAE Thorny Catfishes   (32 genera • 94 species)
Subfamily WERTHEIMERINAE
Subfamily ASTRODORADINAE
Subfamily DORADINAE
+ Family AUCHENIPTERIDAE Driftwood Catfishes   (26 genera/subgenera • 122 species)
Subfamily AUCHENIPTERINAE
Subfamily CENTROMOCHLINAE
+ Family CRANOGLANIDIDAE Armorhead Catfishes   (1 genus • 5 species)
+ Family ICTALURIDAE North American Catfishes   (9 genera/subgenera • 52 species/subspecies)
Family HEPTAPTERIDAE Three-barbeled Catfishes   (24 genera • 212 species/subspecies)
+ Family PIMELODIDAE Long-whiskered Catfishes   (32 genera/subgenera • 110 species)
+ Family PHREATOBIIDAE Cistern Catfishes   (1 genus • 3 species)
+ Family PSEUDOPIMELODIDAE Bumblebee Catfishes   (6 genera • 45 species)

Order GYMNOTIFORMES Neotropical Knifefishes   (5 families • 35 genera/subgenera • 242 species/subspecies)
Family GYMNOTIDAE Nakedback Knifefishes   (2 genera • 41 species)
Family RHAMPHICHTHYIDAE Sand Knifefishes   (3 genera • 16 species)
Family HYPOPOMIDAE Bluntnose Knifefishes   (9 genera/subgenera • 46 species)
Family STERNOPYGIDAE Glass Knifefishes   (6 genera • 45 species)
Family APTERONOTIDAE Ghost Knifefishes   (15 genera • 94 species)

Subdivision TELEOSTEI Cohort EUTELEOSTEI
eu-, an intensive (e.g., very), often interpreted as the “true” teleosts but proposed for fishes “mostly of distinctively teleostean level ancestry” (“Division III” fishes in Greenwood et al., 1966, “Phyletic studies of teleostean fishes, with a provisional classification of living forms”), which, at the time, included groups now placed in Subdivision Ostarioclupeomorpha; name and etymology date to Greenwood et al., 1967, “Named main divisions of teleostean fishes”

Order LEPIDOGALAXIIFORMES Salamanderfish
Family LEPIDOGALAXIIDAE   (monotypic)

Superorder PROTACANTHOPTERYGII
protos, first; acanthus, spine; pteron, fin or wing, ray-finned fishes that lack spines and therefore are presumed to resemble ancestors of spiny rayed fishes

Order ESOCIFORMES Pikes and Mudminnows   (2 families • 4 genera • 15 species/subspecies)
Family ESOCIDAE Pikes   (1 genus • 8 species/subspecies)
Family UMBRIDAE Mudminnows   (3 genera • 7 species)

Order SALMONIFORMES Salmonids
Family SALMONIDAE   (17 genera/subgenera • 272 species/subspecies)
Subfamily COREGONINAE Whitefishes       
Subfamily THYMALLINAE Graylings
Subfamily SALMONINAE Trouts, Salmons and Chars

Superorder OSMEROMORPHA
Osmerus, the smelt (Osmeriformes: Osmeridae); morpha, form or shape, i.e., smelt-like fishes

Order ARGENTINIFORMES Marine Smelts   (4 families • 23 genera/subgenera • 96 species)
Family ARGENTINIDAE Argentines   (3 genera/subgenera • 28 species)
Family OPISTHOPROCTIDAE Barreleyes or Spookfishes   (8 genera • 19 species)
Family MICROSTOMATIDAE Pencilsmelts   (3 genera • 22 species)
Family BATHYLAGIDAE Deepsea Smelts   (8 genera • 25 species)

Order GALAXIIFORMES Galaxiids  
Family GALAXIIDAE Galaxiids   (7 genera • 66 species)
Subfamily APLOCHITONINAE Peladillas
Subfamily GALAXIINAE White Bait and Mudfishes

Order OSMERIFORMES Freshwater Smelts   (5 families • 17 genera • 43 species/subspecies)
Family OSMERIDAE Smelts   (6 genera • 17 species/subspecies)
Family PLECOGLOSSIDAE Ayu or Sweetfish   (1 genus • 3 species/subspecies)
Family SALANGIDAE Icefishes or Noodlefishes   (7 genera • 17 species)
Family RETROPINNIDAE Southern Smelts   (2 genera • 4 species)
Family PROTOTROCTIDAE Southern Graylings   (1 genus • 2 species)

Order STOMIIFORMES   (4 families • 66 genera/subgenera • 433 species/subspecies)
Family GONOSTOMATIDAE Bristlemouths   (8 genera • 33 species)
Family STERNOPTYCHIDAE Marine Hatchetfishes   (10 genera/subgenera • 75 species)
Subfamily STERNOPTYCHINAE
Subfamily MAUROLICINAE
Family PHOSICHTHYIDAE Lightfishes   (7 genera • 24 species)
Family STOMIIDAE Barbled Dragonfishes   (41 genera/subgenera • 302 species/subspecies)
Subfamily CHAULIODONTINAE Viperfishes

Subfamily STOMIINAE Scaly Dragonfishes
Subfamily ASTRONESTHINAE Snaggletooths
Subfamily MELANOSTOMIINAE Scaleless Black Dragonfishes
Subfamily MALACOSTEINAE Loosejaws
Subfamily IDIACANTHINAE Black Dragonfishes

Superorder ATELEOPODOMORPHA
Order ATELEOPODIFORMES Jellynose Fishes
Family ATELEOPODIDAE   (4 genera • 11 species)

Superorder CYCLOSQUAMATA
cyclo, cycloid; squamata, scaled, referring to predominance of cycloid scales among its taxa, compared to the Ctenosquamata (=Scopelomorpha), in which ctenoid scales predominate

Order AULOPIFORMES Lizardfishes   (16 families • 50 genera/subgenera • 282 species/subspecies)
Family SYNODONTIDAE Lizardfishes    (4 genera • 81 species)
Subfamily SYNODONTINAE Lizardfishes
Subfamily HARPADONTINAE Bombay Ducks
Family AULOPIDAE Flagfins   (4 genera • 15 species)
Family PSEUDOTRICHONOTIDAE Sand-diving Lizardfishes   (1 genus • 4 species)
Family PARAULOPIDAE Cucumberfishes   (1 genus • 14 species)
Family IPNOPIDAE Deepsea Tripod Fishes   (8 genera/subgenera • 34 species/subspecies)
Subfamily IPNOPINAE
Subfamily BATHYSAUROPSINAE
Family GIGANTURIDAE Telescopefishes   (1 genus • 2 species)
Family BATHYSAUROIDIDAE Largescale Deepsea Lizardfish   (monotypic)
Family BATHYSAURIDAE Deepsea Lizardfishes   (1 genus • 2 species)
Family CHLOROPHTHALMIDAE Greeneyes   (2 genera • 20 species)
Family NOTOSUDIDAE Paperbones or Waryfishes   (3 genera • 17 species)
Family SCOPELARCHIDAE Pearleyes   (5 genera • 18 species)
Family EVERMANNELLIDAE Sabertooth Fishes   (3 genera • 8 species)
Family SUDIDAE   (1 genus  • 2 species)
Family PARALEPIDIDAE Barracudinas   (7 genera • 26 species/subspecies)
Family ALEPISAURIDAE Lancetfishes   (4 genera • 9 species)
Family LESTIDIIDAE Naked Barracudinas   (4 genera • 29 species)

Superorder SCOPELOMORPHA
Scopelus, an old name of some large-eyed fish, from scopus, to look, historically applied to lanternfishes and other pelagic or deep-sea fishes with large eyes; morpha, form or shape

Order MYCTOPHIFORMES Lanternfishes   (2 families • 41 genera/subgenera • 264 species)
Family NEOSCOPELIDAE Blackchins   (3 genera • 6 species)
Family MYCTOPHIDAE Lanternfishes   (38 genera/subgenera • 258 species)

Superorder LAMPRIMORPHA
Order LAMPRIFORMES Opahs   (6 families • 11 genera • 24 species)
Family VELIFERIDAE Velifers   (2 genera • 2 species)
Family LAMPRIDAE Opahs   (1 genus • 2 species)
Family LOPHOTIDAE Crestfishes   (2 genera • 5 species)
Family RADIICEPHALIDAE Tapertail   (monotypic)
Family TRACHIPTERIDAE Ribbonfishes   (3 genera • 11 species)
Family REGALECIDAE Oarfishes   (2 genera • 3 species)

Superorder PARACANTHOPTERYGII
para, near; acanthus, spine; pteron, fin or wing, representing a “spiny-finned radiation more or less comparable morphologically with that of the [superorder] Acanthopterygii”; name and explanation date to Greenwood et al., 1966, “Phyletic studies of teleostean fishes, with a provisional classification of living forms”

Order POLYMIXIIFORMES Beardfishes
Family POLYMIXIIDAE   (1 genus • 10 species)

Order PERCOPSIFORMES Trout-Perches   (3 families • 8 genera • 13 species/subspecies)
Family PERCOPSIDAE Trout-Perches   (1 genus • 2 species)
Family APHREDODERIDAE Pirate Perches   (1 genus • 2 species/subspecies)
Family AMBLYOPSIDAE Cavefishes   (6 genera • 9 species)

Order ZEIFORMES Dories   (6 families • 16 genera • 33 species)
Family CYTTIDAE Lookdown Dories   (1 genus • 3 species)
Family OREOSOMATIDAE Oreos   (4 genera • 10 species)
Subfamily PSEUDOCYTTINAE
Subfamily OREOSOMATINAE
Family PARAZENIDAE Smooth Dories   (3 genera • 4 species)
Subfamily PARAZENINAE

Subfamily CYTTOPSINAE
Family ZENIONTIDAE Armoreye Dories   (3 genera • 7 species)
Family GRAMMICOLEPIDIDAE Tinselfishes   (3 genera • 3 species)
Subfamily MACRUROCYTTINAE
Subfamily GRAMMICOLEPIDINAE

Family ZEIDAE Dories   (2 genera • 6 species)

Order STYLEPHORIFORMES Tube-eye
Family STYLEPHORIDAE   (monotypic)

Order GADIFORMES Cods and Hakes   (13 families • 89 genera/subgenera • 630 species/subspecies)
Family MELANONIDAE Pelagic Cods   (1 genus • 2 species)
+ Family STEINDACHNERIIDAE Luminous Hake   (monotypic)
+ Family BATHYGADIDAE Codhead Rattails   (2 genera • 27 species)
+ Family MACROURIDAE Grenadiers or Rattails   (36 genera/subgenera • 373 species/subspecies)
+ Family TRACHYRINCIDAE Rough Rattails   (3 genera • 8 species)
Subfamily MACROUROIDINAE
Subfamily TRACHYRINCINAE
Family EUCLICHTHYIDAE Eucla Cod   (monotypic)
+ Family MORIDAE Deepsea Cods   (18 genera • 108 species/subspecies)
+ Family MACRURONIDAE Southern Hakes    (3 genera • 7 species/subspecies)
+ Family MERLUCCIIDAE Hakes    (1 genus • 17 species/subspecies)
Family RANICIPITIDAE Tadpole Cod   (monotypic)
+ Family BREGMACEROTIDAE Codlets    (1 genus • 14 species)
+ Family MURAENOLEPIDIDAE Eel Cods    (2 genera • 8 species)
+ Family GADIDAE Cods and Haddocks    (19 genera • 63 species/subspecies)
Subfamily PHYCINAE Phycid Hakes
Subfamily GAIDROPSARINAE Rocklings
Subfamily LOTINAE Burbot, Cusk and Lings
Subfamily GADINAE Cods and Haddocks

Order HOLOCENTRIFORMES Squirrelfishes and Soldierfishes
Family HOLOCENTRIDAE   (8 genera • 88 species)
Subfamily HOLOCENTRINAE Squirrelfishes       
Subfamily MYRIPRISTINAE Soldierfishes