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
Shiloango spiny eel
Mastacembelus shiloangoensis
A neat little African spiny eel from the Shiloango River basin, it stays around 6 inches and shows a row of inky spots along the back. It loves to bury itself in fine sand and come out at dusk for worms and tiny crustaceans, so a soft substrate and tight lid make life way easier.
Shorthead sole
Brachirus breviceps
Brachirus breviceps (the shorthead sole) is a little bottom-hugging flatfish from Australia that lives right on soft sand or mud in shallow coastal water. Its whole thing is staying camouflaged and half-buried, so it is more of a "you spot it and smile" fish than a constant swimmer. Also worth knowing up front: there is basically no solid aquarium-care info published specifically for this exact species, so any tank recommendations are best treated as cautious, general "small sole" guidelines.
Shortspine cardinalfish
Ostorhinchus brevispinis
This is a small deepwater cardinalfish from French Polynesia. It has alternating brown/golden-brown and whitish longitudinal stripes and a dark mark on the caudal peduncle; the name refers to its very short first dorsal-fin spine.
Short-sword platyfish
Xiphophorus continens
Xiphophorus continens is a tiny little wild-type livebearer from the Rio Panuco drainage in Mexico, and the males have just a short "stub" sword instead of the big flowing one you see on common swordtails. They really shine in a planted, oxygen-rich tank with some current, where you can watch the males do their low-key "sneaker" style mating behavior and the females quietly cruise the plants.
Short Zaireichthys (dwarf loach catfish)
Zaireichthys brevis
Zaireichthys brevis is a tiny little African loach catfish from the Congo River basin - think "micro catfish" that spends its time down on the bottom. Its wild habitat is sandy stretches of big river, so it tends to appreciate fine sand and some rocks/cover, and it is more of a look-and-enjoy species than an interactive pet.
Sicklefin chub
Macrhybopsis meeki
Sicklefin chub is a sleek Midwestern river minnow with a neat sickle-shaped dorsal fin. It hugs sandy runs in fast, turbid water and relies on taste more than sight to pick off tiny drifting insects. If you ever keep it, plan on cool, high-oxygen flow and a soft sand river setup.
Signal pearleye
Scopelarchoides signifer
Tiny deep-sea pearleye with wild tubular eyes that let it see forward and sideways at once. It cruises tropical Indo-Pacific midwaters around 300-500 m, so it is a look-dont-keep species rather than an aquarium fish.
Silverbelly cardinalfish
Jaydia photogaster
Jaydia photogaster is a small, nocturnal cardinalfish from the western Pacific that hangs around deeper lagoon patch reefs and tends to be seen solo or in little loose groups. The really neat bit is the silvery belly light-organ system (hence the name) and the subtle dusky bars down the sides - it is one of those understated fish that looks way cooler the longer you stare at it.
Silver Tip Tetra
Hasemania nana
These little guys are like tiny sparks in the tank-silvery bodies with those warm orange "copper" fins that really pop when they're happy and colored up. Keep them in a proper group and you'll see them cruise around together, doing that classic tetra "we're all going this way now" thing, and the males will sometimes flash at each other without it turning into real drama.
Similis annual killifish
Simpsonichthys similis
Simpsonichthys similis is a small Brazilian annual killifish from temporary pools in the São Francisco River basin. Like other annual rivulids, it spawns in the substrate; the eggs develop in a dry medium (diapause) and hatch on re-wetting. Adults are small (roughly 3–6 cm), and the species is best handled as a short-lived, breeding-focused project.
Singapore glassy perchlet
Ambassis kopsii
Ambassis kopsii is one of those cool little see-through mangrove/estuary fish that likes to hang out in a tight group, flashing silver in the light. It naturally lives where fresh and saltwater mix, so it does best when you treat it like a calm, slightly brackish schooling fish and give it lots of friends.
Sixline Wrasse
Pseudocheilinus hexataenia
The Sixline Wrasse is that nonstop little reef torpedo that weaves through rockwork all day hunting tiny critters. It's awesome for picking at pests like small worms/flatworms, but once it settles in it can get pretty territorial-especially in smaller tanks or with similar-shaped fish.