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.
Beluga Sturgeon
One of the largest anadromous fish in the world, native to the Caspian and Black Sea basins. It migrates into major rivers like the Volga and Danube to spawn and is critically endangered.
brackish
Catfish
A vast, worldwide group of scaleless, whisker-faced bottom-dwelling fish; the channel catfish, one of the most familiar North American species, is shown here as representative.
freshwater
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
Bullhead Catfish
A hardy, whiskered bottom-dweller with a rounded tail and mottled brown skin, thriving in muddy, low-oxygen ponds and slow streams across North America.
freshwater
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
Celestial Pearl Danio
A tiny, jewel-like danio with a dark blue body covered in pearly spots and orange-red banded fins, discovered only in the mid-2000s in Myanmar.
freshwater
Blackfin Clownfish
An orange anemonefish with a single white head bar and distinctive black-edged pelvic and anal fins, endemic to reefs around the Maldives and Sri Lanka.
reef
Cabezon
The cabezon is the largest sculpin of the North American Pacific coast, a heavily mottled, scaleless ambush predator that blends into rocky reef and kelp habitat.
saltwater
Bigeye Tuna
A large, deep-diving tuna named for its notably large eyes, adapted for hunting in the dim light of deep water far below the ocean surface.
pelagic
Celebes Rainbowfish
A slender, sail-finned rainbowfish endemic to Sulawesi, easily recognized by its tall, translucent dorsal and anal fins edged in black and yellow.
freshwater
Black Crappie
A silvery panfish mottled with irregular dark speckling, closely related to the White Crappie but preferring clearer water, and one of the most popular schooling panfish in North America.
freshwater
California Grunion
A slender coastal fish famous for coming fully ashore on sandy California beaches during nighttime spawning runs timed to spring high tides.
saltwaterBlack Hagfish
The black hagfish is a jawless, deep-sea scavenger found on the muddy continental slope off the Pacific coast of North America, notable for its uniformly dark coloration.
deepsea
Blue Marlin
A massive, cobalt-blue billfish with a long spear-like bill, the Blue Marlin is one of the fastest and largest predators of the open tropical ocean.
pelagic
Black Marlin
A massive, powerful billfish of the Indo-Pacific known for its rigid, immovable pectoral fins and status as one of the largest bony fish in the ocean.
pelagic
Bighead Carp
A large, big-headed East Asian carp that filter-feeds on zooplankton, closely related to the silver carp and similarly established as an invasive species in North American rivers.
freshwater
Blue Catfish
North America's largest catfish species, silvery-blue to slate gray with a deeply forked tail, native to the Mississippi basin and now established as an invasive predator in several Atlantic drainages.
freshwater
Blacktip Reef Shark
A slender, small reef shark instantly recognized by the bold black tips on all its fins, commonly seen patrolling shallow lagoons and reef flats across the Indo-Pacific.
reef
Blue Whiting
Blue whiting is a slender, silvery-blue deep-water relative of cod that forms enormous schools across the northeastern Atlantic, distinguished by its large eyes and lack of a chin barbel.
pelagic
Black Drum
The Black Drum is a deep-bodied, greyish-black sciaenid with distinctive chin barbels, found in estuaries and coastal waters from the mid-Atlantic to Argentina.
brackish
Blue Ring Angelfish
An Indo-Pacific angelfish named for the vivid blue ring behind its head, with adults displaying a yellow-brown body crossed by curving electric-blue lines.
reef
Bird Wrasse
An Indo-Pacific wrasse instantly recognized by its long, bird-like snout used to probe coral for prey.
reef
Bluegill
A common North American sunfish recognized by its deep, rounded body and the dark blotch on its gill cover, widely found in lakes and ponds and popular with anglers.
freshwater
Blackwing Flyingfish
A stocky, wide-ranging flyingfish named for its large dusky-black pectoral wings, found gliding above open ocean surface waters across much of the world's warm and temperate seas.
pelagic
Blonde Naso Tang
A striking unicornfish with a gray body, black-and-yellow facial markings, and a bright yellow blaze along the back, best known in the aquarium trade as the Indian Ocean's 'blonde' color form.
reef
Blackfin Tuna
The smallest member of the true tuna genus, this fast schooling fish sports a dark blue-black back and yellow, black-edged finlets, ranging through warm western Atlantic waters.
pelagic
Blue Rockfish
A schooling rockfish with dark blue-gray coloring, commonly seen in large numbers around kelp forests and rocky reefs along the Pacific coast of North America.
saltwater
Blackbarred Halfbeak
A silvery halfbeak marked with faint dark vertical bars, common over seagrass beds and reef flats across the Indo-Pacific.
reef
Bogue
The bogue is a slender, silvery schooling sparid common throughout the Mediterranean and eastern Atlantic, feeding on plankton, algae, and small invertebrates in open coastal water.
saltwater
Black Molly
A solid-black, selectively bred color strain of the common molly, the black molly is one of the most recognizable and widely kept aquarium livebearers.
freshwater
Blue Damselfish
A small, brilliant electric-blue damselfish that fiercely defends its patch of shallow Indo-Pacific reef.
reef
Black Swallower
A small deep-sea fish renowned for an extraordinarily distensible stomach that lets it engulf prey several times its own body length and mass in a single strike.
deepsea
Blue Gourami (Three Spot Gourami)
A hardy, adaptable Southeast Asian labyrinth fish named for the two dark spots along its flank that, combined with the eye, form a "three spot" pattern; the wild form is blue-grey with darker mottling.
freshwater
Blue Ling
A slender, deep-water relative of the cod, the Blue Ling lives along northeastern Atlantic continental slopes and forms dense spawning aggregations at specific deep-sea sites.
deepsea
Bluestriped Grunt
A vividly striped Caribbean reef fish with a bright yellow body crossed by narrow electric-blue lines, often seen in dense daytime schools beneath reef ledges.
reef
Bridled Burrfish
A small Caribbean burrfish with fixed, non-erectile spines and a pale body marked with fine dark reticulations and scattered blotches, often resting motionless among seagrass.
reef
Blue Runner
A slender, greenish-blue jack common along the western Atlantic coast, often called the hardtail and known for its schooling habits and role as forage for larger predators.
pelagicBlue Gularis
One of the largest African killifish, males display an elongated lyre-shaped tail and vivid blue-green body with red barring, native to Nigerian and Cameroonian wetlands.
freshwater
Blind Cave Tetra
A ghostly pink, eyeless cavefish descended from surface-dwelling Mexican tetras, adapted over millennia to life in total darkness within Mexican limestone caves.
freshwater
Bocaccio
A large, streamlined rockfish with a prominent lower jaw and reddish-brown to olive coloring, once heavily depleted along the Pacific coast and now the focus of long-term rebuilding efforts.
saltwater
Blobfish
A gelatinous deep-sea sculpin whose flesh is slightly less dense than water, letting it hover just above the seafloor without expending much energy swimming.
deepsea
Blue Green Chromis
A small schooling damselfish with iridescent blue-green coloring, commonly seen in large groups hovering above branching coral on Indo-Pacific reefs.
reef
Bonito
A fast, streamlined relative of the tunas and mackerels, marked by bold dark diagonal stripes across its upper back, found in schools across temperate and warm seas.
pelagic
Botia
A genus of South and Southeast Asian freshwater loaches known for social behavior and varied patterning; the queen loach (Botia dario) is a representative species.
freshwater
Bluefin Trevally
A vividly colored reef jack covered in electric-blue spots, with matching blue fins, patrolling coral reefs across the Indo-Pacific.
reef
Blue Reef Chromis
A slender, brilliant blue schooling fish commonly seen hovering in large numbers above coral reef outcrops throughout the Caribbean and western Atlantic.
reef
Black Sea Bream
A deep-bodied porgy of the Mediterranean and Eastern Atlantic, notable for males that excavate and guard nest depressions on the seabed during spawning.
saltwater
Bluestripe Pipefish
The bluestripe pipefish is a tiny reef pipefish with a bright blue lateral stripe running along a tan or orange body, often seen hovering near crevices where it also cleans parasites from larger fish.
reef