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.
Arctic Cod
Arctic cod, or polar cod, is a small, ice-associated Gadidae found throughout the circumpolar Arctic, recognized by its slender body, deeply forked tail, and role as the region's key forage fish.
pelagic
Basking Shark
The world's second-largest fish, a massive gray-brown filter feeder recognized by its enormous gaping mouth and huge gill slits, often seen basking at the surface in cool temperate seas.
cartilaginous
Atlantic Croaker
The Atlantic Croaker is a silvery-bronze estuarine fish with a single chin barbel and faint wavy mottling, abundant along the western Atlantic coast.
brackish
Bastard Halibut
An alternate name for the olive flounder, a large East Asian coastal flatfish with a muscular olive-brown mottled body, big toothy mouth, and left-sided eyes.
saltwater
Arctic Char
A cold-adapted char of circumpolar northern waters, showing extremely variable coloration and body form across isolated lake and anadromous populations.
freshwater
Atlantic Wolffish
A large, eel-like cold-water fish with powerful crushing jaws, sheltering solitarily in rocky dens across the North Atlantic.
saltwater
Auratus Cichlid
A small, strikingly striped mbuna from Lake Malawi, the auratus cichlid reverses its coloration between sexes as it matures, with golden juveniles giving way to dark, aggressive adult males.
freshwater
Balao
A slender, silvery halfbeak with a needle-like lower jaw that schools near the surface of warm Atlantic waters.
pelagic
Atlantic Cod
A large, heavy-bodied bottom fish with a distinctive chin barbel and three dorsal fins, the Atlantic Cod is one of the North Atlantic's most historically significant and heavily studied fish species.
saltwaterAustralian Lamprey
The Australian lamprey is a primitive, eel-like jawless fish that spends part of its life as a marine parasite before migrating into coastal rivers of southern Australia and New Zealand to spawn.
brackish
Australian Lungfish
One of the most primitive living fish, this large freshwater species has a single lung, paddle-like fins, and a lineage that has remained largely unchanged for over 100 million years.
freshwater
Atlantic Needlefish
A long, slender silvery fish with a needle-like toothy beak, common in coastal and estuarine waters of the western Atlantic where it hunts small fish near the surface.
brackish
Banded Archerfish
A silvery, deep-bodied fish famous for spitting jets of water to knock insects off overhanging vegetation into the water below. Bold dark bands and a flattened, upturned mouth make it easy to recognize.
brackish
Baltic Herring
A smaller, brackish-water subspecies of the Atlantic Herring, the Baltic Herring is adapted to the low-salinity Baltic Sea and forms one of the region's most abundant and ecologically important schooling fish.
brackishAtlantic Silverside
A slender, schooling coastal fish common along the western Atlantic shoreline, marked by a bright silver stripe running down each flank.
brackish
Azure Damselfish
A small, vividly blue damselfish common on Indo-Pacific reef flats and lagoons, easily spotted flitting among coral rubble in loose groups.
reef
Ballan Wrasse
The largest wrasse in northern European waters, a stout rocky-reef fish with highly variable green, brown, or reddish mottling.
saltwater
Argentine Pearlfish
A deep-bodied annual killifish from the pampas of Argentina and Uruguay, marked with pearly white spots. It lives in seasonal ponds and survives dry months as diapausing eggs in the mud.
freshwater
Antarctic Cod
Antarctic cod is a bottom-dwelling notothenioid fish of the Southern Ocean, adapted to near-freezing water and recognized by its mottled brown, camouflaged body and broad head.
saltwater
Atlantic Hagfish
The Atlantic hagfish is a primitive, eel-like, jawless scavenger known for producing enormous quantities of defensive slime and for its ability to feed inside the carcasses of dead or dying animals on the seafloor.
deepsea
American Shad
The largest member of the herring family in North America, this deep-bodied, silvery, anadromous fish spends most of its life at sea before migrating up coastal rivers each spring to spawn.
brackish
Arowana
The arowana is a large, ancient freshwater fish of the Amazon basin, genus Osteoglossum, known for its upturned mouth, long fins, and ability to leap for surface prey.
freshwater
Agujon Needlefish
One of the largest needlefish species, the Agujon Needlefish is a long, torpedo-like predator with an elongated toothy beak, found in warm coastal and offshore waters worldwide.
saltwater
Bigeye Scad Sardine
Often mistaken for a true sardine because of its silvery, schooling habits, the bigeye scad is actually a jack recognizable by its unusually large eyes.
pelagic
Alaska Pollock
An abundant, silvery schooling fish of the cold North Pacific and Bering Sea, closely related to Atlantic Cod and among the most numerous commercially significant fish in the world.
saltwater
Banded Pipefish
The banded pipefish is a slender reef fish patterned with bold reddish-brown and white rings along its entire body, ending in a fan-shaped yellow tail fin marked with a dark spot.
reef
African Pompano
A deep-bodied jack whose juveniles trail extraordinarily long fin filaments while drifting near floating debris, maturing into steep-headed adults over deep reefs and wrecks.
pelagic
Barreleye
The barreleye, or spookfish, is a deep-sea fish with a transparent, dome-shaped head revealing barrel-shaped, upward-rotating tubular eyes, unlike any other fish.
deepsea
American Brook Lamprey
The American brook lamprey is a small, non-parasitic freshwater lamprey found in clean streams across eastern North America, closely related to the Arctic lamprey but never feeding once it reaches adulthood.
freshwater
Banded Knifefish
An elongated, eel-like South American fish that generates weak electric fields to navigate and communicate in murky water.
freshwater
Almaco Jack
A deep-bodied jack with a tall, strongly notched dorsal fin and elongated fin lobes, commonly found around tropical reefs and offshore structure.
reef
Bay Anchovy
One of the most abundant fish in Atlantic and Gulf Coast estuaries, the tiny Bay Anchovy is a key forage species that tolerates a wide range of salinities from open bays to nearly fresh tidal creeks.
brackish
Allis Shad
A large anadromous herring relative native to Europe's Atlantic coast, the Allis Shad spends most of its life at sea but migrates into large rivers each spring to spawn, forming runs that have been much reduced.
brackish
Bandwing Flyingfish
A small, slender flyingfish of the tropical Atlantic, identified by the dark crossbands on its otherwise translucent pectoral wing fins as it glides over the open sea.
pelagic
American Paddlefish
The American paddlefish is a primitive filter-feeding fish famous for its long, paddle-shaped snout, native to the Mississippi River basin of North America.
freshwater
Barramundi Cod
The Australian common name for the panther grouper, a pale gray, black-spotted reef grouper instantly recognizable by its small head and steeply humped forehead.
reef
American Plaice
A right-eyed flounder of the cold North Atlantic, identifiable by its rough scales, curved lateral line, and reddish-brown upper body.
saltwater
Bicolor Angelfish
A vivid dwarf angelfish split sharply into a bright yellow front half and deep blue rear half, a favorite of reef aquarists.
reefAnthias
A small, brightly colored basslet that forms large shimmering schools over reef drop-offs, feeding on drifting plankton.
reef
Barbour's Seahorse
A small, spiny-crowned seahorse native to the coral reefs and seagrass beds of the western Pacific, distinguished by fine dark banding along its snout.
reef
Barred Mudskipper
An amphibious mangrove goby with bulging eyes and muscular fins that lets it crawl and hop across exposed mud at low tide throughout the Indo-Pacific.
brackish
Bicolor Anthias
A small Indo-Pacific reef fish sharply divided in color, with a violet-purple front half and a golden-yellow rear half, forming loose groups above reef structure.
reef
Betta
A small, vividly colored Southeast Asian freshwater fish famed for its flowing fins and the intense territorial aggression of males toward rivals.
freshwater
Albacore
A sleek open-ocean tuna easily recognized by its exceptionally long pectoral fins, ranging widely across temperate seas worldwide.
pelagic
Achilles Tang
A striking black surgeonfish with a bold orange-red teardrop marking near its tail and matching scalpel-like tail spine. It inhabits high-surf reef zones across the Pacific.
reef
Amazon Molly
An entirely female species that reproduces through a rare cloning-like process, the Amazon molly is a biological curiosity native to rivers along the Texas-Mexico border.
freshwater
Alewife
A small, silvery anadromous herring native to the Atlantic coast of North America, recognizable by a single dark shoulder spot, that migrates from the ocean into freshwater rivers and lakes each spring to spawn.
brackish
Allen's Damselfish
A slender, iridescent blue damselfish with a bright yellow tail, native to reefs of the Coral Triangle and known for its striking two-tone coloration.
reef