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.
Maroon Clownfish
The largest and most aggressive anemonefish, with a deep maroon body and bold white or gold bars, fiercely guarding its host anemone.
reef
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
Megrim
A slender, left-eyed flatfish of the Northeast Atlantic and Mediterranean, valued commercially and recognizable by its thin, elongated body and large mouth.
saltwater
Lionfish
A striking, striped reef predator native to the Indo-Pacific, now a widespread and ecologically disruptive invasive species across the Western Atlantic and Caribbean, easily recognized by its fan-like fins and venomous spines.
reef
Mummichog
A stout, hardy killifish common in salt marshes and estuaries along the North American Atlantic coast, well known for its extreme tolerance of changing salinity and oxygen levels.
brackish
Longhorn Cowfish
The Longhorn Cowfish is a boxfish encased in a rigid bony shell, instantly recognizable by the pair of long horns projecting forward above its eyes.
reef
Mono Argentus
A flat, disc-shaped, mirror-silver fish with tall yellow-tinged fins, commonly seen schooling in brackish estuaries and harbors across the Indo-Pacific.
brackish
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
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
Leopard Shark
A slender, boldly patterned houndshark common in shallow California bays, easily recognized by its dark saddle-like blotches and spots.
cartilaginous
Mola Mola
The heaviest bony fish in the world, an enormous, flattened, disc-shaped giant that appears to be missing a tail, often seen basking sideways at the ocean's surface.
pelagic
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
Mudskipper
An amphibious goby that spends much of its life out of water, hopping across mudflats on muscular pectoral fins. Bulging, periscope-like eyes let it watch for predators while it hunts and defends its burrow.
brackish
Lined Seahorse
A medium-sized seahorse of the western Atlantic coast, variably colored from black to bright orange, often marked with fine pale lines on the neck and named for these subtle streaks.
saltwater
Marlin
A large, powerful open-ocean billfish with a long rounded spear-like bill and a tall crested back, prized as one of the ocean's fastest and most sought-after game fish.
pelagic
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
Neon Damselfish
A small, brilliant iridescent blue damselfish with a touch of yellow on the tail, commonly seen in loose groups over rubble and coral on Indo-Pacific reefs.
reef
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
Moon Wrasse
A fast-swimming green Indo-Pacific wrasse with pink-magenta facial streaks and a bright yellow crescent-moon tail.
reef
Lemon Shark
A stocky, yellow-brown coastal shark named for its sandy coloration, recognized by two nearly equal-sized dorsal fins, common in shallow mangrove and reef habitats of the western Atlantic and eastern Pacific.
cartilaginous
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
Leopard Coral Grouper
A striking Indo-Pacific reef predator with a reddish-orange body densely covered in small electric-blue spots, giving it a leopard-like pattern.
reef
Mbu Pufferfish
The Mbu Pufferfish is the largest freshwater pufferfish species, native to Central Africa's Congo River system and known for its maze-like yellow body markings.
freshwater
Florida Gar
A heavily spotted gar endemic to the Florida peninsula, recognized by dark markings covering its head, body, and every fin.
freshwater
Marbled Hatchetfish
A tiny South American fish with a deep, keeled belly and enlarged pectoral fins that let it skim and glide just above the water surface to escape predators.
freshwater
Gudgeon
A small, bottom-dwelling cyprinid with a pair of sensory barbels at the mouth corners, the gudgeon forages over gravel and sand in loose shoals, well camouflaged among stones.
freshwater
Naso Tang
A large surgeonfish with bright orange lips and a yellow tail-base marking, grazing algae along Indo-Pacific reef slopes.
reef
Julii Corydoras
A small, finely spotted armored catfish from coastal Brazil, frequently confused in the trade with the very similar Corydoras trilineatus.
freshwater
Neon Rainbowfish
A small, brilliantly colored rainbowfish from New Guinea whose males flash iridescent blue-violet when displaying to rivals or mates.
freshwater
Jackknife-fish
A boldly black-and-white striped reef drum with a dramatic, curved dorsal fin that resembles the blade of an open jackknife.
reef
Lake Sturgeon
The lake sturgeon is a large, armored, long-lived freshwater fish native to the Great Lakes and Mississippi basin, recognizable by its bony scute rows and shovel-shaped snout.
freshwater
Giant Moray
The Giant Moray is the largest moray eel species, a densely spotted Indo-Pacific reef predator that shelters in crevices by day and hunts fish and invertebrates at night.
reef
Kuhli Loach
An eel-like, nocturnal loach with a banded body that burrows through substrate in streams across Southeast Asia.
freshwater
Giant Gourami
The largest gourami species, a deep-bodied Southeast Asian labyrinth fish that can exceed two feet in length and shifts from an insect-eating juvenile diet to a largely plant-based adult diet.
freshwater
Hedgehog Seahorse
One of the spiniest seahorses, the Hedgehog Seahorse is covered in numerous sharp, elongated body spines that give it a distinctly bristled silhouette against reef rubble.
reef
Green Chromide
A deep-bodied cichlid from South Asian estuaries, olive-green with rows of shimmering pearly spots along its flanks. It is one of the largest brackish-water cichlids and an important species in coastal lagoon ecosystems.
brackish
Halfbeak
The common name for slender, surface-swimming fish of the family Hemiramphidae, marked by a short upper jaw and a long, needle-like lower jaw; the Common Halfbeak represents the group.
saltwater
Gulf Menhaden
A deep-bodied, oily-scaled herring relative that forms enormous schools in Gulf of Mexico estuaries, playing a major role as a forage fish in coastal food webs.
brackish
Gulf Kingfish
The palest and most silvery of the surf kingfishes, found in wave-swept sandy beaches from the mid-Atlantic to the Gulf of Mexico.
saltwater
Grunt Sculpin
A small, oddly shaped sculpin with an elongated, beak-like snout and orange-and-brown striped body, famous for mimicking the appearance of an empty giant acorn barnacle shell.
saltwaterGuppy
A small livebearing fish native to northeastern South America, famous for the males' vividly colored, ornately shaped tails and its worldwide popularity in the aquarium hobby.
freshwater
Green Tiger Barb
A green-toned color variant of the popular Tiger Barb, retaining the same bold dark bands and active, schooling nature as the classic orange form.
freshwater
Grenadier
Grenadiers, or rattails, are deep-sea fish found on ocean slopes worldwide, unmistakable for their oversized head tapering into a long, thin, whip-like tail with no true tail fin.
deepsea
Grey Gurnard
A bottom-dwelling gurnard with an armored, pale-spotted grey-brown back and large bluish pectoral fins, common across sandy shelf waters of Europe.
saltwater
Green Wrasse
A slender Mediterranean wrasse, often green to brownish, associated with seagrass meadows and rocky reefs.
saltwater
Grouper
A heavy-bodied reef predator with a large mouth and mottled camouflage pattern, known for lying in wait near reef structure before ambushing fish and crustaceans.
reef
Grey Snapper
The grey snapper, also called mangrove snapper, is an adaptable western Atlantic species with a dark reddish-grey body and a dark streak through the eye, ranging from mangrove estuaries to coral reefs.
reef
Kryptopterus
A small, almost entirely transparent Southeast Asian catfish whose internal skeleton and organs are visible through its glass-like body, popular in the aquarium trade.
freshwater