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.
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
Atlantic Blue Marlin
A massive, powerful billfish of the open Atlantic, known for its cobalt-blue back, silvery flanks, and a long spear-like bill used to stun prey.
pelagic
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.
brackish
Atlantic Saury
A slender, silvery, beaked fish of the open North Atlantic, closely related to needlefish, recognized by its elongated jaws and a row of small finlets near the tail.
pelagic
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
Balloonfish
The balloonfish is a spine-covered porcupinefish that inflates by gulping water when threatened, using its beak-like teeth to crush hard-shelled prey on tropical reefs.
reef
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
Atlantic Flyingfish
A streamlined, silvery flyingfish of the tropical Atlantic that uses its oversized wing-like pectoral fins to glide over the surface for long distances to escape predators.
pelagic
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
Atlantic Halibut
The Atlantic halibut is the largest flatfish species, a right-eyed flounder with a diamond-shaped body found on cold seabeds of the North Atlantic.
saltwater
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
Asian Swamp Eel
A slender, limbless, snake-like eel native to rice paddies and marshes of East and Southeast Asia, known for its air-breathing ability and its establishment as an introduced species in parts of the southeastern United States.
freshwater
Auriga Butterflyfish
A very common Indo-Pacific butterflyfish with cross-hatched white body, yellow rear, and often a trailing dorsal filament.
reef
Arctic Lamprey
The Arctic lamprey is a jawless, circumpolar species found across Arctic and sub-Arctic rivers and coastal waters of North America and Asia, recognized by its sucker mouth and slender eel-like body.
brackish
Albacore
A sleek open-ocean tuna easily recognized by its exceptionally long pectoral fins, ranging widely across temperate seas worldwide.
pelagic