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.
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
Kokanee Salmon
Kokanee are a landlocked, non-migratory form of sockeye salmon that spend their entire life in freshwater lakes, turning bright red during their autumn spawning run into tributary streams.
freshwater
Bull Trout
A large, cold-water char native to the Pacific Northwest and Rocky Mountains, requiring exceptionally cold, clean streams and listed as threatened across much of its range in the United States.
freshwater
Common Lumpsucker
Shaped like a rounded ball with a sucker disc instead of pelvic fins, the Common Lumpsucker drifts through cold North Atlantic waters before moving inshore to spawn on rocky shores.
saltwater
Channel Catfish
A widespread North American catfish recognized by its deeply forked tail, scattered dark spots, and long barbels around the mouth. It is the most abundant catfish species in the United States.
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
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
Yellowtail Flounder
A slender northwest Atlantic flatfish recognized by the rusty-yellow tint along its tail edge, reddish-brown upper body, and preference for sandy continental shelf bottoms.
saltwater
Pollock
A streamlined, greenish-bronze cod relative that schools around rocky reefs and wrecks in the northeastern Atlantic, told apart from cod by its protruding lower jaw and lack of a chin barbel.
saltwater
Lyretail Killifish
A slender, non-annual West African killifish named for the male's elegant lyre-shaped tail, ranging in color from golden-orange to deep red across its native populations.
freshwater
Masu Salmon
Masu salmon is the southernmost and westernmost Pacific salmon species, native to Japan, Korea, and the Russian Far East, notable for males that can mature and spawn entirely within freshwater.
freshwater
Moonlight Gourami
A sleek, silvery-green Mekong basin gourami with an iridescent sheen and vivid orange-red pelvic fin filaments, notably lacking the dark body spots seen in many related species.
freshwater
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
Gambusia
A small, hardy North American livebearer famous for its voracious appetite for mosquito larvae, widely introduced worldwide for mosquito control with significant ecological consequences.
freshwater
European Brook Lamprey
The European brook lamprey is a small, non-parasitic freshwater lamprey found across Europe, closely related to the river lamprey but spending its entire life cycle in streams and never feeding as an adult.
freshwater
Brown Trout
A golden-brown salmonid native to Europe and western Asia, marked by dark and reddish spots along its body, now widely introduced across the globe. It favors cool, clear rivers, streams, and lakes.
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
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
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
Pajama Cardinalfish
A small, egg-shaped reef fish with a yellow-striped head and red-spotted rear body, resembling patterned sleepwear.
reefSkipjack Shad
A slender, fast-swimming river herring native to major drainages of central and eastern North America, the Skipjack Shad is known for leaping clear of the water while pursuing prey near the surface.
freshwater
Silver Lamprey
The silver lamprey is a freshwater parasitic lamprey of central and eastern North America, recognized by its single-cusped teeth and silvery body, native to Great Lakes and Mississippi River basin drainages.
freshwater
Saithe
The saithe, or coalfish, is a dark, streamlined Gadidae found in North Atlantic coastal and offshore waters, recognized by its near-black coloring and preference for open midwater schooling.
pelagic
Nassau Grouper
A stocky Caribbean reef grouper known for its ability to rapidly change color and pattern, from pale to dark barred phases, and for forming large seasonal spawning aggregations now heavily protected.
reef