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.
Figure-Eight Puffer
A small brackish-water pufferfish named for the bold black figure-eight-shaped markings across its yellow-green back. Like other puffers, it can inflate its body with water as a defense against predators.
brackish
Electric Eel
A long, air-breathing South American knifefish, not a true eel, famous for generating powerful electric discharges from specialized organs used to stun prey, navigate, and defend itself.
freshwater
Estuarine Stonefish
A heavily camouflaged, encrusted-looking fish that lies motionless on muddy estuary and mangrove bottoms across the Indo-Pacific, bearing venomous dorsal spines as a natural defense.
brackish
European Anchovy
A slender, small-bodied schooling fish with a distinctive pointed snout and underslung mouth, found in enormous shoals along European and North African coasts and throughout the Mediterranean.
pelagic
Cisco
Cisco, also known as lake herring, are slender silvery relatives of whitefish that form large open-water schools in the cold lakes of the northern United States and Canada, feeding mainly on plankton.
freshwater
Brook Trout
A colorful char native to cold, clear streams of eastern North America, marked by worm-like back markings and red spots haloed in blue along its sides. It is highly sensitive to water quality and temperature.
freshwater
Butterfish
A disc-shaped, silvery schooling fish of the northwestern Atlantic shelf, the Butterfish migrates seasonally between inshore and offshore waters and often shelters near jellyfish as a juvenile.
pelagic
Bluehead Wrasse
A small, abundant Caribbean reef fish famous for changing color and sex as it matures, with terminal males developing a striking blue head and green body. It is one of the most numerous fish on western Atlantic reefs.
reef
Big-belly Seahorse
The largest seahorse species in the world, recognized by its notably rounded, protruding belly and mottled brown-yellow coloration, found along the temperate coasts of Australia and New Zealand.
saltwater
Bala Shark
A torpedo-shaped, silver freshwater fish named for its shark-like body outline, though it is a true minnow relative, not a shark. Bold black margins on its fins make it a striking, fast-swimming schooler of Southeast Asian rivers.
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
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
Starry Flounder
The starry flounder is a distinctive North Pacific flatfish recognized by alternating orange and black bands across its fins and rough, star-shaped scales, and notable for tolerating a wide range of salinities.
brackish
Peacock Goby
A small, brightly colored sleeper goby from Papua New Guinea, with a rounded body patterned in iridescent blue spots over an orange-to-purple base. A dark eye-like spot near the tail gives it its scientific species name.
freshwaterPacific Sardine
A silvery, spot-flanked schooling fish found along the Pacific coast of North America, famous for boom-and-bust population cycles driven by shifting ocean temperatures and historically massive coastal schools.
pelagic
Midas Blenny
An elongated, brightly colored blenny that ranges from golden-yellow to blue-violet and often mimics the appearance and swimming style of similarly colored basslets. It hovers near reef crevices along drop-offs.
reef
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
Mono
A shimmering, disc-shaped fish with a strongly flattened body and tall, angular fins, native to Indo-Pacific estuaries. Adults school in brackish coastal waters and shift gradually toward full seawater as they mature.
brackish
Long-snouted Seahorse
The long-snouted seahorse, also known as the spiny seahorse, is a slender species of the Mediterranean and northeastern Atlantic with a proportionally long snout and often ornate skin filaments used for camouflage in seagrass beds.
saltwater
Dusky Grouper
The dusky grouper is a large, dark brownish-grey grouper native to rocky reefs of the Mediterranean and eastern Atlantic, once heavily depleted by spearfishing and now a conservation priority in parts of its range.
reef
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
Whitetip Reef Shark
A slender nocturnal reef shark marked by distinctive white-tipped fins, often seen resting motionless inside reef caves and under ledges by day across the Indo-Pacific.
reef
Yellowtail Rockfish
A slender, olive-brown Pacific rockfish with yellow-tinted fins that schools in large midwater aggregations over rocky reefs and open water along the North American coast.
saltwater
Western Brook Lamprey
The western brook lamprey is a small, non-parasitic jawless fish that spends most of its life as a burrowing larva in Pacific Northwest streams before a brief, non-feeding adult stage.
freshwater