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.
Greenland Halibut
A cold-water, deep-sea North Atlantic and Arctic flatfish with a dark body on both sides, a large toothy mouth, and a less flattened posture than typical flounders.
deepsea
Horn Shark
A small, harmless bottom shark with heavy brow ridges and two sharp dorsal spines, common along the California coast.
cartilaginous
Greenland Cod
The Greenland cod is a stocky, cold-adapted cod relative found in shallow coastal Arctic waters around Greenland and eastern Canada, distinguished by its deep body and short head.
saltwaterHerring
One of the world's most abundant fish, the herring forms colossal schools in cold North Atlantic waters and underpins much of the region's marine food web.
pelagic
Lawnmower Blenny
The Lawnmower Blenny is a mottled brown-and-cream reef fish with a stocky body and comb-like teeth, known for grazing algae off rock and rubble surfaces on shallow Indo-Pacific reefs.
reef
Hake
A slender, silvery predatory fish with a large toothy mouth and two widely separated dorsal fins, Hake patrol continental shelf waters of the northeastern Atlantic and Mediterranean.
saltwater
Longsnout Seahorse
A slender, long-snouted seahorse native to the western Atlantic that anchors itself to soft corals and mangrove roots with its prehensile tail. It comes in a wide range of colors, from yellow and orange to red and black.
reef
Green Terror
A robust, iridescent-green South American cichlid whose bold turquoise spangling and feisty temperament earned it its combative common name.
freshwater
Longfin African Conger
A slender, sand-dwelling conger with a distinctly long dorsal fin and a two-tone body, found burrowing along reef flats and lagoons across the Indo-Pacific and East African coast.
reefHardhead Catfish
A common western Atlantic sea catfish with a bony plate on its head, short barbels, and a mouthbrooding reproductive strategy shared with related sea catfish.
saltwater
Lemon Sole
A thick-bodied northeastern Atlantic flatfish with smooth, slippery, mottled reddish-brown skin, a small mouth, and a preference for firm sand or gravel seabeds.
saltwater
High-hat
A striking black-and-white striped reef drum related to the jackknife-fish, easily recognized by its tall, elongated dorsal fin.
reef
Long-spined Porcupinefish
The Long-spined Porcupinefish is a spiny, balloon-shaped fish that can inflate its body dramatically, erecting long, permanently attached spines as a defense against predators.
reef
Gulf Flounder
A left-eyed flatfish common along the Gulf of Mexico and southeastern Atlantic coast, marked by three distinctive eyespots arranged in a triangle.
saltwater
Koi
Ornamental color varieties of the Amur carp, selectively bred in Japan for centuries into hundreds of red, white, black, and gold patterns kept in decorative ponds worldwide.
freshwater
Kissing Gourami
A large, elongated Southeast Asian gourami famous for its thick, protrusible lips, which it uses to graze algae and to engage in "kissing" contests, an actual test of strength between rivals.
freshwater
Iridescent Shark
Despite its name, this is a large freshwater catfish, not a shark, recognized in juveniles by an iridescent sheen and dark stripes that fade with age.
freshwater
Horse-eye Jack
A deep-bodied, silvery jack with an oversized eye, commonly seen in large stationary schools around Caribbean and Florida reefs and harbors.
reef
Humphead Wrasse
A massive, long-lived Indo-Pacific reef wrasse known for the prominent bulging hump on its forehead and its role as one of the few predators of toxic crown-of-thorns starfish.
reef
Horseface Loach
The Horseface Loach is a slender, burrowing loach recognized by its elongated, downturned snout, native to sandy-bottomed rivers of Southeast Asia.
freshwater
Jaguar Cichlid
A large, powerfully built Central American predator whose irregular black leopard-like blotches over a pale body give it its common name.
freshwater
Japanese Halfbeak
A slim, silvery surface fish with a long lower jaw, common in coastal and brackish waters around Japan, Korea, and China.
brackish
Kribensis
A small, colorful West African dwarf cichlid best known for the vivid magenta belly females display, especially during courtship.
freshwater
Huchen
The huchen, or Danube salmon, is Europe's largest freshwater salmonid, a powerful river predator native to the Danube basin that has become increasingly rare due to damming and habitat fragmentation.
freshwaterJapanese Sardine
A schooling pelagic fish abundant in the waters around Japan, the Japanese Sardine undergoes dramatic multi-decade population cycles and forms one of the largest single-species biomasses in the northwest Pacific.
pelagic
Jacksmelt
A larger, long-bodied silverside found along the California and Baja coasts, often schooling in bays and nearshore waters alongside the smaller Topsmelt.
saltwater
Gulf Pipefish
The Gulf pipefish is a small, slender pipefish common in seagrass beds and estuaries around the Gulf of Mexico and southeastern United States, notable for tolerating salinities ranging from full seawater to nearly fresh water.
brackish
Klein's Butterflyfish
A golden-brown Indo-Pacific butterflyfish with a dark eye bar and dusky patches, common on many reefs.
reef
Hillstream Loach
A flattened, disc-bodied loach adapted to cling to rocks in fast mountain streams, using its wide fanned fins as a natural suction system.
freshwater
Knight Goby
A small, boldly patterned goby from Southeast Asian estuaries, pale gray-white with scattered black spots and blotches along its slender body. It perches on the bottom, propped on its fused pelvic fins, watching for small prey.
brackish
Harlequin Tuskfish
A vividly colored wrasse with a turquoise-blue body crossed by orange bars and prominent protruding tusk-like teeth used to crush hard-shelled prey. It inhabits coral-rich reef slopes across the western Pacific.
reef
King Mackerel
A large, streamlined mackerel of the warm western Atlantic, prized as a fast offshore game fish and recognizable by its silvery, unmarked body.
pelagic
Hogfish
A large western-Atlantic wrasse with a pig-like snout and long front dorsal spines, able to rapidly change color.
reef
Kelp Rockfish
A mottled brown-and-olive rockfish closely tied to kelp forest habitat along the California coast, where its coloring provides camouflage among kelp stipes and rocky understory.
saltwater
Hammerhead Shark
A shark instantly recognizable by its flattened, laterally extended hammer-shaped head, often seen in large daytime schools near seamounts and coastal areas.
cartilaginous
Island Trevally
The Island Trevally is a deep-bodied jack found around Indo-Pacific reefs, recognized by faint yellow-orange spots scattered along its silvery flanks and a forked yellow tail.
reef
Honeycomb Moray
One of the largest and most strikingly marked moray eels, its pale body covered in bold black honeycomb-shaped blotches makes it instantly recognizable across Indo-Pacific reefs.
reef
Golden Shiner
A slender, deep-bodied North American minnow with brassy golden-silver sides, the golden shiner is among the continent's most widely used baitfish, thriving in weedy ponds and slow-moving water.
freshwater
Longnose Butterflyfish
A bright yellow butterflyfish with a greatly elongated snout used to pluck small invertebrates from reef crevices. It is one of the most widespread and recognizable butterflyfish across the Indo-Pacific.
reef
Great White Shark
A massive, torpedo-shaped predator found in cool coastal and offshore waters worldwide, easily recognized by its sharp countershading and crescent-shaped tail.
cartilaginous
Inshore Hagfish
The inshore hagfish is a jawless, slime-producing scavenger found burrowing in muddy coastal seabeds off Japan, Korea, and China, closer to shore than most other hagfish species.
saltwater
Glass Knifefish
A slender, near-transparent South American fish that swims using a continuous rippling fin and emits a weak electric field to sense its surroundings.
freshwater
Humbug Damselfish
A small white damselfish marked with three bold black bars and a clear tail, living in tight groups among the branches of Indo-Pacific coral colonies.
reef
Gold Gourami
A selectively bred, solid golden-yellow color variety of the Three Spot Gourami, developed for the aquarium trade and sharing the same hardy, adaptable biology as its wild-type relative.
freshwater
Ide
A robust, silvery cyprinid of large European rivers and lakes, the ide (commonly bred as the golden 'orfe') forms active surface shoals and is a widely stocked ornamental pond fish worldwide.
freshwater
Goliath Grouper
One of the largest bony fish on Atlantic reefs, the goliath grouper is a massive, mottled brown ambush predator that shelters around wrecks, caves, and mangrove-lined shorelines.
reef
Keeltail Needlefish
A slender needlefish easily identified by the raised keel-like ridge on either side of its tail base, found cruising the surface of warm coastal waters worldwide.
saltwater
Giant Grouper
The largest bony fish found on coral reefs, the giant grouper is a massive Indo-Pacific predator with a huge head and mouth, capable of ambushing prey as large as small sharks and turtles.
reef