Fish Encyclopedia
Search and identify 1,000+ fish species — freshwater, saltwater, reef, and pelagic — with habitat, size, diet, behavior, and how to tell them apart.
Pygmy Corydoras
The Pygmy Corydoras is one of the smallest armored catfish species, a tiny schooling fish native to slow-moving tributaries of the Amazon basin.
freshwater
Plains Killifish
A slender, sand-colored killifish adapted to the wide, shallow, shifting-sand rivers of the North American Great Plains, marked with narrow dark vertical bars.
freshwater
Opaline Gourami
A marbled blue-and-silver color variety of the Three Spot Gourami, bred for its swirling opalescent pattern while retaining the same hardy biology and behavior as the wild form.
freshwater
Marbled Swamp Eel
A snake-like, limbless eel of Central and South American swamps and slow rivers, marked with a mottled, marbled pattern and equipped with air-breathing lungs-like tissue for surviving in stagnant water.
freshwater
Pikehead
An elongated, pike-shaped ambush predator from Southeast Asian blackwater swamps, unique among the gourami family as an obligate carnivore that snaps up prey with lightning speed.
freshwater
Mosquitofish
A small, drab livebearer native to the central and southeastern United States, the mosquitofish is famous for its voracious appetite for mosquito larvae and has been introduced worldwide for pest control.
freshwater
Pike Livebearer
A large, elongated predatory livebearer from Central America with a pike-like head and mouth built for ambushing small fish.
freshwater
Masu Salmon
Masu salmon is the southernmost and westernmost Pacific salmon species, native to Japan, Korea, and the Russian Far East, notable for males that can mature and spawn entirely within freshwater.
freshwater
Prickly Sculpin
A large freshwater sculpin of Pacific coast rivers and lakes, named for the tiny prickle-like scales scattered along its sides, and among the largest members of its genus.
freshwater
Mozambique Tilapia
A hardy, deep-bodied cichlid native to southeastern Africa, the Mozambique tilapia tolerates a huge range of salinities and temperatures and has become one of the world's most widely introduced freshwater fish.
freshwater
Pristella Tetra
A translucent, pale-golden tetra whose semi-transparent body reveals internal structures, marked by distinctive black-and-yellow fin patches.
freshwater
Merry Widow
A small, peaceful Central American livebearer with a translucent grayish body and a distinctive dark spot near the gill cover, popular among hobbyists for decades.
freshwater
Moonlight Gourami
A sleek, silvery-green Mekong basin gourami with an iridescent sheen and vivid orange-red pelvic fin filaments, notably lacking the dark body spots seen in many related species.
freshwater
Pink Salmon
The smallest and most abundant Pacific salmon, notable for its strict two-year life cycle and the pronounced dorsal hump males develop when spawning.
freshwater
Mekong Giant Catfish
One of the largest freshwater fish on Earth, this critically endangered giant inhabits the deep main channel of the Mekong River and undertakes long spawning migrations.
freshwater
Platy
A small, compact livebearer native to Mexico and Central America, the platy is prized for its bright colors, peaceful nature, and ease of breeding in home aquariums.
freshwater
Pygmy Swordtail
One of the smallest members of the swordtail genus, this diminutive Mexican livebearer lacks the elongated tail sword typical of its larger relatives.
freshwater
Mrigal
A slender, silvery Indian carp and one of the three traditional Indian major carps, the mrigal is a bottom-feeding scavenger with a small mouth and short barbels, farmed widely across South Asia.
freshwater
Midas Cichlid
A large, variably colored Central American cichlid, ranging from mottled gray to solid gold-orange, known for its bold and often combative nature.
freshwater
Panda Corydoras
A small, pale armored catfish with bold black patches around the eyes and tail, resembling its namesake in miniature form.
freshwater
Pallid Sturgeon
The pallid sturgeon is a large, pale, endangered fish of the Missouri and Mississippi rivers, adapted to fast, turbid water with a flattened snout and reduced eyes.
freshwater
Madagascar Rainbowfish
An elongated, silvery rainbowfish from Madagascar's eastern rainforest rivers, recognized by its bold black-edged yellow and red fin markings.
freshwater
Marbled Lungfish
The largest of the African lungfish, marked with a dark mottled pattern, capable of surviving prolonged drought buried in a mucus-lined mud burrow.
freshwater
Marble Trout
Marble trout are a large, distinctively patterned native trout of the Balkan Peninsula, named for the marbled, olive-and-brown pattern covering their body, and are now considered vulnerable due to hybridization with introduced brown trout.
freshwater
Madtom
A small North American freshwater catfish that hides under rocks by day and carries venomous pectoral and dorsal spines used defensively when handled or threatened.
freshwater
Pacu
A large Amazon and Orinoco characin related to piranhas but herbivorous, identified by its reddish belly and flattened, fruit-crushing teeth.
freshwater
Lemon Tetra
A pale yellow tetra from the Amazon basin, easily recognized by its lemon-tinted body and black-edged anal fin bordered in yellow.
freshwater
Paddlefish
A large, ancient North American fish with a long paddle-shaped snout used to detect plankton, related to sturgeon rather than sharks despite its shark-like tail.
freshwater
Julii Corydoras
A small, finely spotted armored catfish from coastal Brazil, frequently confused in the trade with the very similar Corydoras trilineatus.
freshwater
Loach Goby
The Loach Goby is an elongated, flat-bodied fish that clings to rocks in fast-flowing Indo-Pacific streams, combining goby and loach-like features.
freshwater
Penguin Tetra
An Amazonian characin recognized by its bold black tail stripe and unusual head-up swimming posture resembling a penguin's stance.
freshwater
Japanese Eel
The Japanese Eel is an East Asian catadromous fish that migrates from freshwater rivers to offshore Pacific spawning grounds, and is now classified as Endangered.
freshwater
Peacock Cichlid
A brilliantly colored Lake Malawi cichlid whose males flash iridescent blues, oranges, and yellows to attract mates and rivals alike.
freshwater
Lake Wanam Rainbowfish
A deep-bodied rainbowfish endemic to the small crater Lake Wanam in Papua New Guinea, with males showing rich orange-red body coloration.
freshwater
Northern Brook Lamprey
The northern brook lamprey is a small, non-parasitic freshwater lamprey of the Great Lakes and St. Lawrence River region, believed to have evolved from a parasitic ancestor but never feeding as an adult.
freshwater
Jardini Arowana
A large, metallic-scaled arowana from northern Australia and New Guinea, known for its bronze-green body and upward-facing mouth built for surface feeding.
freshwater
Keyhole Cichlid
A calm, mild-mannered South American cichlid named for the distinctive dark keyhole-shaped blotch on its flank, this species is known for its subdued coloration and unusually peaceful temperament.
freshwater
Mottled Sculpin
A small, mottled brown freshwater sculpin found in clear, cold streams and lakes across North America, identified by its large head, wide pectoral fins, and lack of scales.
freshwater
Largemouth Bass
A robust, olive-green freshwater fish with a distinctive dark lateral stripe and a very large mouth, one of North America's most popular sport fish now established worldwide.
freshwater
Muskellunge
A large, elongated predatory fish native to North American lakes and rivers, marked by dark vertical bars or spots on a lighter body. It is the largest member of the pike family and a well-known apex freshwater predator.
freshwater
Nile Tilapia
A deep-bodied African cichlid with bold stripes on its tail fin, the Nile tilapia is one of the world's most widely distributed freshwater fish through aquaculture and introductions.
freshwater
Molly
A hardy, adaptable livebearer native to Mexico and Central America, the common molly thrives in fresh, brackish, and even marine water and is one of the most popular beginner aquarium fish.
freshwater
Leopard Bush Fish
A round-bodied Congo basin ambush predator patterned with dark leopard-like spots, prized in aquariums for its striking camouflage and air-breathing labyrinth organ.
freshwater
Least Killifish
One of the smallest vertebrates in North America, the least killifish is a tiny livebearer native to slow, vegetated wetlands of the southeastern United States despite its misleading name.
freshwater
Lionhead Cichlid
Also known as the buffalohead cichlid, this Congo River rapids specialist gets its "lionhead" nickname from the rounded, maned appearance of the fatty hump on a mature male's forehead.
freshwater
Montezuma Swordtail
A Mexican livebearer notable for the male's exceptionally long, trailing sword-shaped tail extension, among the longest relative to body size of any swordtail.
freshwater
Licorice Gourami
A tiny, secretive Sumatran blackwater specialist with a dark body crossed by iridescent turquoise stripes and red-edged fins, one of several closely related "licorice gourami" species from acidic peat swamps.
freshwater
Murray River Rainbowfish
A slender, schooling rainbowfish native to Australia's Murray-Darling river system, displaying subtle pink-red stripes and yellow-tinted fins along its silvery-blue body.
freshwater