Search Species
Search for fish species by common or scientific name, or use filters to browse by water type, size, temperament, and difficulty.
Found 541 species
Iberian arch-mouthed nase
Iberochondrostoma lemmingii
This is a temperate Iberian river leuciscid that typically inhabits middle-to-lower river reaches with weak to moderate current and abundant aquatic vegetation. It feeds largely on algae/detritus and also zooplankton and small aquatic invertebrates. It is a native conservation-interest species in parts of its range and is not commonly encountered in the aquarium trade.
Ichthyborus monodi
Ichthyborus monodi
A long-nosed African characin from lowland rivers in Nigeria, Benin, and Cameroon. It reaches about 8-9 inches and is an active, streamlined predator that will take small fish and even nip fins, so it needs sturdy, fast tankmates and lots of open swimming space. Super cool fish if you like oddball characins, but it is not a community tetra.
Imparfinis catfish
Imparfinis piperatus
Imparfinis piperatus is a tiny Brazilian heptapterid catfish that spends its time down on the bottom, scooting around like a little stream goblin. It stays really small (around 3.2 cm SL max), and the neat part is the subtle mottled/striped look and those long barbels that make it look way more "catfish" than its size suggests. Not super common in the aquarium trade, but it is a cool pick if you are into South American stream setups.
Imparfinis cochabambae
Imparfinis cochabambae
A little three-barbeled catfish from the upper Madeira-Beni system, this guy hugs the bottom and zips between stones once the lights go low. Keep it in clean, well-oxygenated flow with plenty of hiding spots and it will come out for sinking meaty foods. It stays small, so a calm community of similar-sized fish works nicely.
Imparfinis nemacheir
Imparfinis nemacheir
A small, nocturnal stream catfish from Colombia and the Lake Maracaibo basin, it zips around at lights-out and spends daytime wedged under wood and rocks. The coolest thing about it is the long thread-like first dorsal-fin ray and extra-long whiskers. Give it flow, high oxygen, and meaty bites like insect larvae and it will settle in nicely.
Indian glassy fish
Parambassis ranga
This is the classic see-through "glassfish" where you can literally see the bones and organs-super cool in a planted tank with calm tankmates. They're happiest when you keep a little crew of them (they get braver and way more active in a group). Also: skip any dyed/painted ones-those fish are usually in rough shape from the process.
Indian spaghetti-eel
Monopterus hodgarti
This is a small swamp-eel from northeast India that lives in super shallow, muddy stream edges and will happily bury itself when it feels exposed. Its an obligate air-breather, so it will cruise up for gulps of air and can be a real escape artist if you leave gaps. Breeding behavior is neat too - the male builds/guards a nest or burrow.
Inle loach
Yunnanilus brevis
This is the quirky little Inle loach from Myanmar (Lake Inle/He-Ho plain) that cruises around midwater in a loose shoal and often swims head-up (normal behavior). Unlike many loaches, it does well in calmer, well-planted setups with good water quality, and it’s best kept in groups to encourage natural schooling.
Intermedia lebiasina
Lebiasina intermedia
Lebiasina intermedia is one of those super-obscure South American lebiasinids where the science side knows it, but the hobby basically never sees it. It tops out around 10.7 cm (about 4.2 inches) and, like its close relatives, its whole vibe is a slim, surface-oriented little predator that would love a tight lid and some structure up top.
Iris hap
Haplochromis iris
A rare Lake Victoria hap that sticks to insect snacks and shows classic mouthbrooder behavior. Think medium, feisty Victorian cichlid energy - great color and attitude when settled, but it appreciates space and stable hard, alkaline water.
Iskenderun bleak
Alburnus kotschyi
Alburnus kotschyi is a freshwater bleak endemic to southern Turkey, known from the Seyhan and Ceyhan river drainages and coastal streams between Ceyhan and Arsuz (İskenderun Bay watershed). It is not a standard aquarium-trade species.
Italian spring goby
Knipowitschia punctatissima
This is a tiny little freshwater goby from northern Italy that spends most of its time glued to the bottom, scooting between sand, gravel, and cover. In the wild it is tied to cool, clear spring-fed habitats, so it does best in an oxygen-rich tank with gentle flow and lots of little hiding spots. Its size is cute, but its needs are kind of specific, and its wild status makes it a fish I would not treat as a casual impulse buy.