Search Species
Search for fish species by common or scientific name, or use filters to browse by water type, size, temperament, and difficulty.
Found 665 species
Jadova minnow
Delminichthys jadovensis
This is a tiny karst-stream minnow that lives in just a sliver of Croatia, and it actually ducks into subterranean waters (or hides in mud) when conditions get rough. Its whole life is tied to super clear, slow-flowing streams, so it is more of a conservation fish than something you will realistically see for sale.
Jaguar livebearer
Jenynsia onca
Jenynsia onca is an unusual anablepid livebearer often called a one-sided livebearer; males have an asymmetrical gonopodium and mating may involve lateralized positioning (though some sources dispute strict left/right-only pairing). In aquaria they are active schooling fish that prefer cooler, well-oxygenated water and are best kept in groups.
Japanese deepwater clingfish
Aspasma minima
Aspasma minima is a tiny little marine clingfish from southern Japan that spends its life hugging hard surfaces with that cool suction-disc belly. Its whole vibe is secretive and bottom-oriented, more like a micro predator you design a tank around than a "community fish" you toss in with everything.
Japanese scorpionfish
Rhinopias argoliba
Rhinopias argoliba is one of those sit-and-wait ambush predators that basically looks like a chunk of reef rubble until it decides to inhale something whole. Its claim to fame is that pale teardrop mark under the eye and the more "clean" look (fewer frilly appendages) compared to some other Rhinopias. Super cool fish, but you plan the whole stocking list around its mouth size and the fact it is a venomous scorpionfish.
Jewelled blenny
Salarias fasciatus
This is the classic "lawnmower" blenny - a little reef perch-fish that spends its day scooting around the rocks, scraping film algae and looking like it has tiny eyebrows. Give it a mature tank with lots of live rock to graze and it will stay busy all day, but if the tank is too clean it can slowly starve unless you supplement greens.
Jingxi Yunnan loach
Yunnanilus jinxiensis
This is a small Chinese stone loach from Guangxi, and its whole vibe is "hang out on the bottom and poke around". It comes from a pretty specific local area (Jingxi County), so you are not likely to see it in the regular aquarium trade. If you do run into one, think cool, clean, well-oxygenated water and lots of hiding spots like you would for other little nemacheilid loaches.
Jordan's cod
Gadella jordani
This is a deep-water morid cod from the western Pacific that hangs out way down on the continental slope, hundreds of meters below the surface. It reaches about 28 cm and even carries a little luminous organ on its belly. Super interesting fish to learn about, but it is not a home aquarium candidate.
Jupiaba apenima
Jupiaba apenima
A tiny stream-loving tetra out of the upper Tapajos basin in Brazil, Jupiaba apenima is an active little shoaler that loves clean, moving water. It even has a neat forward-pointing pelvic spine, and there are Moenkhausia that mimic its look in the wild. Give it a soft, slightly acidic, well-oxygenated setup and a good-sized group and it will stay busy all day.
Jupiaba tetra
Jupiaba pinnata
Jupiaba pinnata is a small South American characin from the Guianas that stays around 5.8 cm standard length. Its vibe is very "tetra-like" - quick, active, and happiest when its kept in a proper group with open swimming space and some cover.
Jupiaba yarina
Jupiaba yarina
A small characin endemic to Brazil’s Tapajós River drainage (type locality: Rio Arinos) that reaches about 7.7 cm SL. It inhabits clearwater streams with low conductivity and slightly acidic pH (about 6.0–6.8); keep in clean, well‑oxygenated water and a group to encourage schooling behavior.
Kaie's shield pleco
Corymbophanes kaiei
Small loricariid catfish from the Upper Potaro (Potaro River drainage above Kaieteur Falls) in Guyana; described as having distinct alternating light/dark bands on the caudal fin and diagnostic armored-pleco morphology.
Kamdem's killifish
Fundulopanchax kamdemi
This is a rainforest Fundulopanchax from western Cameroon, found in shallow swampy pools and tiny forest creeks. Males get a really striking red band along the belly area and are classic "surface killi" escape artists, so a tight lid is non-negotiable. It's not a hard fish once settled, but it appreciates very soft, acidic-leaning water and some cover so the female can get breaks from a pushy male.