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
Halfbelt wriggler
Xenisthmus semicinctus
Xenisthmus semicinctus is a tiny little reef-dweller (barely 2 cm) from the Rowley Shoals off Western Australia. It is one of those blink-and-you-miss-it benthic fishes that lives right down on shallow coral reef habitat, kind of wriggling and hugging cover instead of swimming out in the open. Super cool fish biologically, but its so small and specialized that it is basically never seen in the normal aquarium trade.
Harelip cusk
Ophidion lagochila
This is a tiny Caribbean cusk-eel that sticks to sandy bottoms around reefs from Bermuda and the Bahamas down to Venezuela. It tops out under 3 inches and spends a lot of time tucked into the sand, darting out for tiny crustaceans and worms. Super cool little oddball, but you almost never see it for sale and it really needs a mature, stable marine setup with a decent sand bed.
Harlequin Rasbora
Trigonostigma heteromorpha
Harlequin rasboras are those little coppery-orange fish with the bold black "wedge" on their sides that somehow look even better once they're cruising in a group. Give them a nice school and some plants to weave through and they'll do this tight, synchronized swimming thing that's honestly kind of hypnotic.
Hartt's banjo catfish
Bunocephalus hartti
Bunocephalus hartti is a tiny little banjo catfish from the Sao Francisco basin in Brazil that lives its best life looking like a dead leaf and pretending it does not exist. Give it sand and leaf litter and it will vanish for days, then suddenly pop out at night like a little cryptid vacuuming up food off the bottom.
Hawaiian surf sardine
Iso hawaiiensis
Iso hawaiiensis is a tiny surf-zone silverside that lives right in the splashy, wave-battered edge of rocky headlands and reefs. Its whole vibe is fast, nervous, and built for rough water, so it is way more of a cool natural-history fish than a typical home-aquarium resident.
Head-and-Tail Light Tetra
Hemigrammus ocellifer
This little tetra does a neat trick in the light-there's a shiny "headlight" spot near the gills and a glowing "taillight" at the base of the tail, so the whole school kind of sparkles as they turn. They're super chill in a group, and they look way better the bigger the shoal is and the more plants you give them to cruise through.
Hermaphroditus mangrove killifish
Kryptolebias hermaphroditus
This is one of those weirdly amazing little mangrove killifish where most individuals are self-fertile hermaphrodites, so a single fish can produce eggs on its own. In the wild its tied to Brazilian mangroves and coastal canals, and it tends to live a pretty secretive, solo life in shallow, mucky, low-oxygen spots.
Hexi stone loach
Triplophysa hexiensis
This one is a little taxonomic curveball: Triplophysa rossoperegrinatorum (Prokofiev, 2001) is treated as a synonym of Triplophysa hexiensis in major references, so in the hobby you will basically want to think of it as T. hexiensis. Its a bottom-dwelling river loach from northern China that likes clean, well-oxygenated water and spends a lot of time hugging the substrate and darting between rocks.
Hi-fin headstander barb
Oreichthys cosuatis
Oreichthys cosuatis is a tiny Indian/Bangladeshi barb where the males can throw up a really cool tall dorsal fin and some nice red/yellow accents when they settle in. They spend a lot of time cruising midwater and picking around for food, and they do best when you keep them in a proper little group so they feel bold.
Highbody longnose gudgeon
Microphysogobio alticorpus
Little bottom-hugger from Taiwan’s fast, well-oxygenated streams that spends its day scooting over gravel and picking at biofilm between snacking on tiny insects. Keep a small group over a gritty-sandy bed with good current and they’ll settle in and school nicely, especially if you feed fine live or frozen foods.
Highfin Toadfish
Torquigener altipinnis
This is a little Southwest Pacific puffer that hangs over sandy areas and has those tall, sickle-y dorsal and anal fins that give it the "highfin" look. In photos it is usually a brown-grey fish dusted with milky white spots, and the original description even mentions bright yellow on the lower half and fins. Like most puffers it is a curious, nippy little carnivore, and it is not a great "community tank" type of fish.
Highland swordtail
Xiphophorus malinche
Xiphophorus malinche is a smaller, cooler-water swordtail from fast, clear rivers in Mexico, and the males can show a really neat golden-brown look with blue/purple sheen plus a short yellow sword. It is a livebearer, but it is not the "toss it in a warm community tank" kind of swordtail - it does best kept cool with very clean, oxygen-rich water.