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
Long-barbel torrent catfish
Chimarrichthys longibarbatus
A chunky Chinese hillstream catfish with extra-long whiskers and a body built to hug slick rocks in roaring current. It thrives in cool, super-oxygenated flow and spends its day clinging to stones and prowling for meaty bites. You will also see it listed under the older name Euchiloglanis longibarbatus.
Long-dorsal Yasuhikotakia (no established common name)
Yasuhikotakia longidorsalis
This is one of those super-under-the-radar Mekong botia/loach species that you almost never see for sale. It stays fairly small (around 8 cm/3 inches max reported), but it still acts like a proper botiid - busy, social, and very into wedging itself under wood and rocks when it wants to chill.
Long-finned glass tetra
Xenagoniates bondi
Xenagoniates bondi is a small South American characin from the Orinoco basin and nearby coastal drainages of Venezuela and Colombia. It has been reported as an aggressive fin-nipper, so it may not be suitable for slow or long-finned community fish.
Long-finned goby
Valenciennea longipinnis
This is that sand-sifting goby that pairs up, digs tidy little burrows, and keeps the substrate looking fresh while it snacks on tiny critters. Give it a mature sand bed and a tight lid, and it will reward you with tons of personality and those blue cheek markings showing off while it works.
Longfin sculpin
Jordania zonope
Jordania zonope is a super cool coldwater marine sculpin from the NE Pacific that clings to rocks and kelp and will even hang vertically on rock faces. Males get very territorial in breeding season, and some individuals are reported to act like little cleaner fish on bigger predators like lingcod - wild stuff for a fish this small.
Longray fangjaw
Zaphotias pedaliotus
This is a tiny deep-sea bristlemouth that lives way down in the midwater-dark and comes up and down the water column on a day-night cycle. Its little light organs (photophores) and even a slight nightly color shift are part of the whole "life in the deep" vibe - super cool, but absolutely not a home-aquarium fish.
Longtail pencilsmelt
Nansenia longicauda
This one is a deepwater pencilsmelt that lives way down in the mesopelagic zone, so its more of a research-species than an aquarium fish. It tops out around 13 cm and seems to show up in patchy spots in the subtropical Atlantic and North Pacific, typically hundreds of meters down.
Long tail pipefish
Festucalex prolixus
This is a tiny little marine pipefish from the Western Central Pacific, and it tops out around 3.6 cm standard length. What's wild is that most of what we know comes from planktonic specimens collected in the upper water column, with adults expected deeper than about 40 m - so it is not really an aquarium species you will run into.
Lowe's tetra
Hyphessobrycon loweae
This is a tiny Upper Xingu tetra that can glow gold in the right light, with males showing that cool elongated dorsal fin. It does best when you keep a real group and give it a calm, planted setup so it feels bold enough to come out and color up.
Lucap sole
Zebrias lucapensis
A small marine demersal sole (family Soleidae) described from Lucap Bay / Hundred Islands area of Lingayen Gulf, Philippines; known from very limited records. Aquarium care information is not species-specific in the literature; if kept, husbandry would likely follow general small marine sole/flatfish needs (fine sand, peaceful tankmates, benthic meaty foods).
Lutea sleeper
Eleotris lutea
Eleotris lutea is a tiny little sleeper (eleotrid) that hangs out on the bottom in coastal/estuary type habitats and tends to just park itself and watch the world go by. Its wild environment is listed as marine and brackish (and it is amphidromous), so it is one of those fish people often mis-label as "freshwater goby" even though it usually does best with some salt and stable conditions.
Lyretail dottyback
Pseudochromis steenei
Pseudochromis steenei is a punchy little reef dottyback from Indonesia and northern Australia that loves living in the rockwork and claiming a cave as its own. Its lyre-shaped tail and bold purple-yellow look really stand out, but its attitude can be bigger than its body, so tankmate choice matters.