Search Species
Search for fish species by common or scientific name, or use filters to browse by water type, size, temperament, and difficulty.
Found 654 species
Japanese dory
Zenion japonicum
Zenion japonicum is a small deepwater dory from way down on the continental slope - silvery, big-eyed, and kind of "alien-cute" in that zeiform way. This is not an aquarium fish in any normal sense (it lives hundreds of meters deep in cold water), but it is a really neat bycatch species with that classic dory shape and spiny fins.
Japanese silver-biddy
Gerres equulus
Gerres equulus (Japanese silver-biddy) is a temperate, demersal coastal mojarra from the northwest Pacific (southern Korea to southern Japan), typically over sandy shallows; it is generally reported as absent from the Ryukyu Islands. It is primarily a coastal fish and is not commonly maintained in home aquaria; if kept, provide ample open swimming space and stable marine conditions.
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.
Jonathan's cusk-eel
Neobythites jonathan
Neobythites jonathan is a deepwater cusk-eel from the western Pacific (Solomon Sea) that lives way down on the lower shelf/upper slope. It is a small, slender bottom-associated fish with a bold ocellus (eye-spot) on the dorsal fin - cool little bit of "fake eye" patterning you see in a bunch of Neobythites.
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.
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.
Kampen's ilisha
Ilisha kampeni
Kampen's ilisha is a small, silvery coastal herring-relative that cruises nearshore waters and will also push into rivers when it feels like it. Its whole vibe is fast, open-water, plankton-and-small-fish hunting - not really a cozy planted-tank fish, more like a little pelagic sprinter that wants room and current.
Kanazawa sand lance
Ammodytoides kanazawai
Think of a tiny silver dart that lives to dive into sand - that is this little sand-burrowing planktivore from Japan’s Ogasawara Islands. It tops out around 6.3 cm and was described in 2013 from a specimen trawled at roughly 95-99 m off Chichijima, so you pretty much never see it in home aquariums. Neat fish to read about, but best left in the ocean unless you run a serious marine setup with open water and fine sand for it to rocket into. ([fishbase.se](https://fishbase.se/summary/Ammodytoides-kanazawai.html))
Kaup's pipefish
Enneacampus kaupi
Enneacampus kaupi is a skinny little West African pipefish that likes to lurk through algae and basically cosplay as a piece of vegetation. Its whole vibe is slow, sneaky, and ultra-picky at feeding time - super cool if you enjoy target-feeding and watching hunting behavior up close. It shows up from brackish estuaries and coastal rivers, so a slightly brackish setup is often the safest long-term direction.
Kazunagi
Zoarchias veneficus
A tiny eel-like prickleback from Japans cool rocky shores, it threads through seaweed and crevices like a living shoelace. Tops out around 7 cm and spends its time peeking from rock cracks and snapping up tiny crustaceans, so a tank full of snug caves is its happy place.
Kelp gunnel
Ulvicola sanctaerosae
This is a skinny little kelp-forest perch that literally hangs out up in the kelp canopy and chills on the fronds. One of the coolest bits is how it uses its tail to wrap onto kelp like a grip, then picks off tiny crustaceans drifting by. Not really an aquarium trade fish, but its a super neat West Coast oddball if you ever see one while diving.