Search Species
Search for fish species by common or scientific name, or use filters to browse by water type, size, temperament, and difficulty.
Water Type
Search for fish species by common or scientific name, or use filters to browse by water type, size, temperament, and difficulty.
Found 352 species
Gymnotus darwini
Gymnotus darwini is a smaller banded knifefish from coastal river drainages in Pernambuco, northeastern Brazil. Like other Gymnotus, it navigates and hunts using a weak electric field and tends to be most active after lights-out, cruising along the bottom and through cover. It is a cool oddball fish, but its exact aquarium needs are not well documented because it is a recently described species and not common in the trade.
Yunnanilus macrogaster
This is a little Chinese stone loach from a weedy marsh system in Yunnan, and it tops out around 7 cm (under 3 inches). Its name literally points at the chunky, swollen-belly look (macrogaster = large stomach), and it is an insect-and-worm picker that hangs along the bottom.
Iodotropheus declivitas
Iodotropheus declivitas is a little Lake Malawi mbuna that hangs around rocky reefs and spends a lot of its day picking at algae and tiny bits of food off the rocks. It stays pretty small for an mbuna, but it still does that classic cichlid thing of claiming a cave and showing off once it settles in. The big catch is its ID and availability - its often discussed alongside (and sometimes confused with) Iodotropheus sprengerae.
Eustomias decoratus
Eustomias decoratus is a deep-sea dragonfish (family Stomiidae) from the western central Atlantic around Bermuda. Like other Eustomias, it is a pelagic predator built for the dark - long body, big mouth, and a chin barbel used in hunting and signaling. This is absolutely not an aquarium species in any normal sense, since its real habitat is open ocean at depth and it will not tolerate typical captive conditions.
Yunnanilus polylepis
Yunnanilus polylepis is a tiny, newly-described stone loach from Yunnan, China that lives over plants in a deep pool, not a raging riffle. Males and females even look different (males show a dark side stripe), and the species name is literally about having lots of scales, which is a fun oddball trait for this group.
Moenkhausia pittieri
Diamond tetras are one of those fish that look kind of plain in the bag, then you get them settled in and they start throwing off this glittery, diamond-like shine when the light hits them-super satisfying to watch. They're active, always cruising around the midwater, and in a nice little school they'll do that tight, synchronized swimming thing that makes the tank feel alive.
Valenciennea puellaris
This is that sand-sifting goby you'll see cruising the bottom, taking huge mouthfuls of sand and spitting it out like a little construction crew. It's awesome for keeping a sandy substrate looking clean, but it'll also redecorate-so anything sitting on the sand is gonna get buried or undermined sooner or later. Super cool personality too, especially once it picks a favorite burrow and starts "working" all day.
Sphaerophysa dianchiensis
This is a tiny Chinese nemacheilid (stone loach) that lived on the bottom in Lake Dianchi, Yunnan. Sadly, its whole story in the hobby is basically that it is a super-local endemic that is listed as Critically Endangered and may even be gone from the wild, so it is not something you should expect to ever see for sale.
Moenkhausia doceana
Moenkhausia doceana is a Brazilian characin from the Doce and Mucuri river basins - basically a regional "lambari" type tetra. In the wild it hangs in the water column of clear, moving streams and picks off insect larvae and other little buggy bits, so it tends to do best in a roomy tank with good flow and a group of its own kind.
Diapoma terofali
This is a little South American characin from the Parana-Uruguay system that stays pretty small but has a neat "glandulocaudine" twist - males have a special caudal gland tied to breeding. In a calm planted setup they act like a typical small tetra-ish fish, cruising midwater and looking best in a group.
Melanotaenia praecox
These little rainbows are like living sparks-electric blue bodies with those punchy red/orange fins, and they look even better the more you keep together. They're constantly cruising the mid-water, flashing at each other and doing that classic rainbowfish "look at me" shimmy, especially when the lights first come on or at feeding time.
Ambastaia sidthimunki
This is the little "Sid" loach people fall in love with once they see a whole group doing their goofy zoomies and clicking at each other. They stay tiny but act like big loaches - always busy, always social, and way more confident when you keep them in a proper gang. Give them sand, hiding spots, and lots of buddies and they really shine.