Pisces - fish - a classification of fishes

I based this classification of fishes on two different sources.

For the higher categories (subphylum to superorder), I followed the traditional Linnaean classification of fishes given in most textbooks—such as Animal Diveristy, 2nd ed. (2000) (see also 3rd ed., 2002) and Zoology, 3rd ed. (1996) (see also 5th ed., 2001).

For the various orders of fishes, I followed Nelson's authoritative book Fishes of the World, 3rd ed. (1994). I also got the species figures from there. I didn't follow Nelson's classification of the higher groups of fish because Nelson's scheme contradicted all the up-to-date college textbooks I found. Nelson's scheme is on the cutting edge of fish classification, but for that very reason it is controversial and highly subject to change.

My other sources included Paxton & Eschmeyer, Encyclopedia of Fishes, 2nd ed. (1998) and Carl E. Bond, Biology of Fishes, 2nd ed. (1996).

Two final notes. The word fishes may not be in common usage, but it is used by scientists to refer to multiple fish species. Also, I use "Pisces" even though it's not the name of any taxonomic group, because there is no one taxonomic group for fishes. The Latin pisces means "fish."

						Described living species		Stories
Subphylum Vertebrata. Vertebrates. The main distinction of vertebrates is that they have a skull surrounding their brain; hence this subphylum is sometimes called Craniata. The vast majority of them also possess a spinal vertebral column; hence their other, more common name Vertebrata.							51,628 total; 24,618 fish
	Superclass Agnatha. Jawless fishes. Fish that have no jaws, no paired appendages, nor (in the case of hagfishes) even a true backbone, possessing instead a segmented notochord.						84
		Class Myxini. Hagfishes. A group of small, primitive, jawless, ocean-dwelling fishes, scavenging their food from dead and dying fish and invertebrates.					43
		Class Cephalaspidomorphi. Lampreys. Another group of small, primitive, jawless fishes. Many are parasites, latching onto the bodies of freshwater fish. Others, non-parasitic, are able to eat only in their larval form, dying as adults soon after reproducing.					41
	Superclass Gnathostomata. Jawed fishes and tetrapods. Vertebrates that possess jaws and usually a set of paired appendages. This includes 99.7% of all living fishes. It also includes all the tetrapods: amphibians, reptiles, birds, and mammals.						51,544 total; 24,534 fish
		Class Chondrichthyes. Cartilaginous fishes. Fishes whose skeletons are made of cartilage rather than bone, whose teeth are not fused to their jaws, and whose bodies lack a swim bladder.					846
			Subclass Elasmobranchii. Sharks and rays. This large group includes two widely recognized groups: sharks and rays. Typically, sharks are large, torpedo-shaped, marine carnivores, hunting and scavenging other sea creatures. And yet there are filter-feeding sharks, sharks of many different shapes, and sharks ranging from less than 20 cm (8 in.; dwarf lanternshark) to 12 m (39 ft.; whale shark; world's largest fish). Rays are fishes with broad bodies, winglike fins, and long tails, usually living on the shallow seabed and preying on invertebrates.				815
			Subclass Holocephali. Chimaeras. Bizarre-looking, often grotesquely shaped deep-sea fishes of the Arctic and Antarctic, lacking scales and with a long tail. Various chimaeras are also called ratfishes, rabbitfishes, and ghostfishes.				31
		Class Osteichthyes. Bony fishes. Fish that have a skeleton made at least partly of bone, and that usually have a swim bladder. This includes 96.2% of all living fishes.					23,688
			Subclass Sarcopterygii. Lobe-finned fishes: coelacanths and lungfishes. Coelacanths are lobe-finned fishes, thought to be extinct until a species was discovered in 1938 in Africa; a second species was discovered in the late 1990s in Indonesia. Lungfishes are unique in that they possess lungs and can live for a limited time outside of water. With their lungs and their lobed fins resembling proto-limbs, it's easy to see how these fishes are believed to be the closest living thing to the fishes that evolved into amphibians 350 million years ago.				7
			Subclass Actinopterygii. Ray-finned fishes. Fishes that have paired fins with sturdy rays, lacking fleshy lobes. This includes 96.2% of all living fishes.				23,681
				Superorder Chondrostei. Chondrostean ray-finned fishes. Ray-finned fishes that have a skeleton made mostly of cartilage, though partly of bone. This relatively primitive group retains into adulthood the notochord shared by invertebrate chordates.			36
						Order Polypteriformes. Bichirs. Small, elongate, freshwater fishes of Africa, with a distinctive row of dorsal finlets down their backs.	10
						Order Acipenseriformes. Sturgeons and paddlefishes. Sturgeons are northern-hemisphere fishes covered with distinctive armor-like plates. Paddlefishes are freshwater fishes of China and the U.S., with long, paddle-shaped snouts.	26
				Superorder Neopterygii. Modern bony fishes. Bony ray-finned fishes that have a number of advanced characteristics: the same number of fin rays as support bones therefor, an improved upper jaw structure, and tooth-plates to help grind food. This group includes 96.0% of all living fishes.			23,645
					Nonteleost bony fishes. Scientists agree that among modern bony fishes, the most important dualism is between teleost and nonteleost fishes. Nonteleosts are the more primitive of the two, lacking certain tail bones that give other bony fishes more swimming power. (According to my research, neither this group nor the teleost fishes have any specific taxonomic rank.)		8
						Order Semionotiformes. Gars. Long fishes of North America, inhabiting mostly freshwater, having armorlike, "ganoid" scales and a long, beaklike snout.	7
						Order Amiiformes. Bowfin. A single small, freshwater species in North America, the closest living relative of the teleost fishes.	1
					Teleost bony fishes. Nearly all modern bony fishes are among the teleosts, possessing certain tail bones, called uroneurals, that provide greater swimming power and permit a greater diversity of body shapes. This includes 96.0% of all living fishes.		23,637
						Order Osteoglossiformes. Bonytongues, elephantfishes, and their allies. Freshwater fishes, mostly tropical. Included are bonytongues, a diverse and widely-distributed group; elephantfishes, African fishes with irregular, often trunk-like snouts; as well as mooneyes and featherbacks.	217
						Order Elopiformes. Tenpounders (ladyfishes) and tarpons. Slender fishes living in tropical and subtropical oceans around the world.	8
						Order Albuliformes. Halosaurs, spiny eels, and bonefishes. Bonefishes are tropical fishes sometimes fished for sport. Halosaurs and spiny eels are deep-sea fishes.	29
						Order Anguilliformes. Eels. This highly successful order consists of "true eels," those that are believed to share a common ancestry. Eels are long, thin, snake-like fishes, with a highly reduced set of fins, and usually live in the ocean. Exaples include snake eels, worm eels, moray eels, conger eels, freshwater eels, and many others.	738
						Order Saccopharyngiformes. Gulper eels. These deep-sea, eel-like fishes are among the most bizarre of all the vertebrates, with huge gaping mouths and enlargable stomachs. Little is known of these rarely-seen deep-sea fish.	26
						Order Clupeiformes. Herrings, anchovies, and their allies. These small fish are of great commercial importance to humans. Included are herrings, which include sardines, shads, sprats, and pilchards; anchovies; and a few others.	357
						Order Gonorhynchiformes. Shellears and their allies. A small order of fishes, living in the rivers of Africa and the Indian and Pacific oceans. Examples include the milkfish, beaked salmons, shellears, and snake mudhead.	35
						Order Cypriniformes. Carps and their allies. Freshwater fishes that are native and widespread throughout Eurasia, Africa, and North America. These fish are unique in that they lack jaw teeth, possessing instead teeth in the back of their throat. Examples include carps, minnows, loaches, suckers, and algae eaters.	2,662
						Order Characiformes. Characins and their allies. Fishes that live almost exclusively in the lakes, rivers, and streams of Africa and Latin America. Examples include characins, tetras, piranhas, pencilfishes, voladoras, and many others.	1,343
						Order Siluriformes. Catfishes. Highly successful fishes characterized by their whisker-like sensory organs called barbels, and by their sometimes venomous fin spines. They are common, mostly freshwater fish, to be found on all continents except Antarctica.	2,405
						Order Gymnotiformes. Knifefishes. Long, very slender fishes, inhabiting South American lakes and rivers.	62
						Order Esociformes. Pikes and mudminnows. Two freshwater fish families of the Northern hemisphere. Pikes are long, sharp-toothed carnivores; mudminnows are much smaller, sometimes used by anglers as bait.	10
						Order Osmeriformes. Smelts and their allies. A diverse group of small, salmonlike fish. Included are the ocean-going smelts and barreleyes; the tiny herring smelts and microstomatids; the skinny icefishes and noodlefishes; the deep-sea slickheads and tubeshoulders; and the freshwater salamanderfish and galaxiids.	236
						Order Salmoniformes. Salmons and their allies. This order consists of a single successful and commercially important family: the salmons and their close relatives. This group lives entirely in the Northern hemisphere-some in freshwater, others in saltwater, in which case they return to freshwater to spawn. Included are salmons, trouts, chars, graylings, whitefishes, ciscoes, and others.	66
						Order Stomiiformes. Dragonfishes and their allies. Another group of bizarre fishes of the deep sea, most of them having light organs, and some of them looking like really monstrous sea serpents. They include dragonfishes, hatchetfishes, snaggletooths, bristlemouths, lightfishes, viperfishes, and loosejaws.	321
						Order Ateleopodiformes. Jellynose fishes. Long, flabby, bottom-dwelling, deep-sea fishes, about which biologists know very little.	12
						Order Aulopiformes. Lizardfishes and their allies. A wide variety of ocean-dwelling fishes, including the offshore lizardfishes and Bombay ducks; the deep-sea ipnopids and barracudinas (not to be confused with barracudas); the fierce, predatory daggertooths and lancetfishes; the continental-shelf-dwelling greeneyes and aulopuses; and the sharp-eyed telescopefishes and pearleyes.	219
						Order Myctophiformes. Lanternfishes and neoscopelids. The light-emitting lanternfishes may account for as much as 65% of all deep-sea, non-bottom-dwelling fish. Neoscopelids comprise another, lesser-known family of deep-sea fish.	241
						Order Lampridiformes. Oarfishes and their allies. A group of highly unusual ocean fishes. The enormous oarfishes are thought to be responsible for many sea-serpent stories; their relatives include ribbonfishes, opahs, velifers, and crestfishes.	19
						Order Polymixiiformes. Beardfishes. Marine fishes of middle depths with two whiskerlike "barbels" underneath their chins.	5
						Order Percopsiformes. Trout-perches and their allies. Small, freshwater fishes of North America, including trout-perches, the pirate perch, cavefishes, and swampfishes.	9
						Order Ophidiiformes. Cusk-eels and their allies. Eel-like fishes with small heads, tapering bodies, and smooth scales, living in oceans around the world. Included are cusk-eels, brotulas, carapids, and aphyonids.	355
						Order Gadiformes. Cods, hakes, and their allies. This order consists mostly of marine fishes in temperate and cold oceans. It includes the cods and hakes, which are some of the most important marine food fishes of the Northern hemisphere; as well as grenadiers (rattails), bottom-dwelling ocean fishes with long tails.	482
						Order Batrachoidiformes. Toadfishes. A single family of fishes with broad heads and round bodies, living near shore in tropical and temperate areas.	69
						Order Lophiiformes. Anglerfishes. The fishes in this order are interesting in that they possess a bony rod with a fleshy tip, which they use as bait to lure prey close to their mouths. They live in nearly all oceanic environments, from the tropics to cold temperate waters, from shallow shores to the deep sea.	297
						Order Mugiliformes. Mullets. Coastal fishes that live in ocean or brackish water, tropical or temperate. They feed on organic debris, and are important as food fish.	66
						Order Atheriniformes. Silversides and their allies. Small, elongate fishes that tend to live in schools. They live in both freshwater and saltwater, and in both tropical and temperate environments. Examples include silversides, rainbowfishes, blue-eyes, priapum fishes, and others.	285
						Order Beloniformes. Flying fishes and their allies. Included among these small, elongate fishes are flying fishes, with their winglike fins and their gliding ability; needlefishes and halfbeaks, with their unusually-shaped jaws; freshwater ricefishes of southeast Asia; and tropical, marine sauries.	191
						Order Cyprinodontiformes. Killifishes and their allies. A variety of tropical and subtropical fishes, inhabiting mostly freshwater, and including many popular aquarium fish. Included are killifishes, rivulines, topminnows, guppies, mollies, swordtails, pupfishes, and others.	807
						Order Stephanoberyciformes. Whalefishes and their allies. A collection of strange-looking, marine, deep-sea fishes, including the large whalefishes and bigscales, the rare pricklefishes and gibberfishes, and the exotic mirapinnids and largenose fishes.	86
						Order Beryciformes. Squirrelfishes and their allies. A collection of ocean-going fishes, including tropical squirrelfishes and soldierfishes; deep-sea fangtooths and spinyfins; widespread roughies and alfonsinos; heavily-armored pinecone (pineapple) fishes; and luminescent flashlight (lanterneye) fishes.	123
						Order Zeiformes. Dories and their allies. Fishes with compressed, sunfish-shaped bodies, inhabiting ocean coasts. Examples include dories, oreos, boarfishes, tinselfishes, and the parazen.	39
						Order Gasterosteiformes. Pipefishes and their allies. Unusual fishes, mostly marine, and most of them having distinctive long, tubular snouts. Included are pipefishes, seahorses, ghost pipefishes, snipefishes, shrimpfishes, trumpetfishes, cornetfishes, seamoths, sticklebacks, tubesnouts, the sand eel, tubesnouts, and the paradox fish.	257
						Order Synbranchiformes. Swampeels and their allies. Freshwater, eel-like, and virtually finless fishes, inhabiting tropical and subtropical lakes and rivers. Examples include swampeels, spiny eels, and chaudhuriids.	87
						Order Scorpaeniformes. Scorpionfishes and their allies. A large and diverse set of fishes, both freshwater and marine, with distinctive bony struts across their cheeks. Though distributed worldwide, most are tropical, and some are quite exotic. Included are scorpionfishes, velvetfishes, searobins (gurnards), flatheads, greenlings, sculpins, oilfishes, poachers, lumpfishes, and snailfishes.	1,271
						Order Perciformes. Perches and their allies. This is not only the largest order of fishes; it is also by far the largest order of vertebrates, containing nearly one-fifth of all vertebrate species. And it is as diverse as it is large, so diverse that its 9,000+ fish may not have a common ancestor. They live everywhere there is water, from the tropics to the arctic, from freshwater to saltwater, from wide estuaries to tiny mountain streams. They range in size from less than 1 cm (1/2 in.) (some gobies) to around 4.5 m (14 ft) (black marlin). Just a few examples of perciform fishes include angelfishes, archerfishes, armorheads, bandfishes, barracudas, basses, basslets, bigeyes, billfishes, blennies, bluefishes, butterfishes, butterflyfishes, cardinalfishes, chubfishes, cichlids, clingfishes, combtooth blennies, croakers, cutlassfishes, damselfishes, dartfishes, dolphinfishes, dottybacks, dragonets, drums, eelblennies, eelpouts, emperors, fusiliers, glassfishes, goatfishes, gobies, gouramies, grunters, grunts, gunnels, hawkfishes, icefishes, jacks, jawfishes, kelpfishes, knifejaws, leaffishes, mackerels, marblefishes, medusafishes, mojarras, moonfishes, morwongs, nurseryfishes, parrotfishes, perches, pikeblennies, plunderfishes, pomfrets, pompanos, ponyfishes, porgies, pricklebacks, pygmy sunfishes, quillfish, rabbitfishes, ragfish, remoras, rock whitings, ronquils, roosterfish, roundheads, rovers, sandburrowers, sandfishes, sandlances, sandperches, scats, sea basses, sillagos, sleepers, snakeheads, snappers, snooks, spadefishes, stargazers, sunfishes, surfperches, surgeonfishes, swallowers, sweepers, thornfishes, threadfins, tilefishes, triplefin blennies, trumpeters, tunas, wolffishes, wormfishes, wrasses, wrymouths, and many others.	9,293
						Order Pleuronectiformes. Flatfishes. Fishes with a very unique body plan: their bodies are compressed thin, and both their eyes are pushed over to one side of their head. In this shape, they lie flat on their "blind side," camouflaged well on the ocean floor, except when hunting for food. Examples include flounders, soles, tonguefishes, spiny flatfishes, and citharids.	570
						Order Tetraodontiformes. Triggerfishes and their allies. An unusual and diverse set of fishes that usually live on the ocean bottom near the coast. Included among them are triggerfishes, spikefishes, triplespines, as well as such exotic curiosities as inflatable pufferfishes, prickly porcupinefishes, oddly-shaped boxfishes, and gigantic ocean sunfishes (molas).	339

		Note: The same superclass (Gnathostomata) that includes the two main fish classes (Chondrichthyes and Osteichthyes) also includes all the tetrapod classes:
		Class Amphibia. Amphibians. Class Reptilia. Reptiles. Class Aves. Birds. Class Mammalia. Mammals.					5,819 7,131 9,620 4,440

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