Explore our growing database of freshwater fish species. Each profile includes detailed care requirements, compatibility data, and environmental needs to help you build the perfect aquarium.
Lepomis gibbosus
A beautiful but aggressive North American native sunfish. Known for its vivid orange, blue, and green speckling and the distinctive red spot on its gill cover. As a temperate/coldwater species, it does not require a heater. They are highly territorial, intelligent, and have large appetites, functioning much like Central American Cichlids in the aquarium.
Pangasius pangasius
A colossal riverine catfish native to the Indian subcontinent. While highly important for aquaculture, they are disastrous for home aquariums. They grow rapidly to enormous sizes (up to 150-300cm), are easily spooked (often resulting in them ramming the tank glass at high speeds), and will swallow any tank mate that fits in their massive mouths.
Mogurnda adspersa
A stunning, robust Australian native fish known for its dark chocolate hues and vivid red, blue, and purple spots. Found in slow-moving creeks and billabongs, they are ambush predators. While generally peaceful with similarly sized or larger tank mates, they will eat any fish or invertebrate that fits into their surprisingly large mouths. They are capable jumpers and require a tight-fitting lid.
Potamalpheops sp.
The Purple Zebra Shrimp is a fascinating, highly adaptable micro-shrimp. Although technically part of the Snapping/Pistol shrimp family (Alpheidae), they are incredibly tiny and entirely peaceful. Famous for their purple striping, they spend most of their time grazing on biofilm and hiding in crevices. While they thrive in freshwater or brackish setups (often kept with Opae Ula), their larvae require saltwater to develop, making captive breeding in freshwater impossible.
Corydoras pygmaeus
One of the smallest Corydoras species, the Pygmy Cory is a true nano fish. Unlike most of their bottom-dwelling cousins, Pygmy Corys are famous for hovering and schooling in the mid-water area. They are extremely peaceful but very shy, requiring a proper school to feel secure. A soft sand substrate is absolutely required to protect their delicate barbels.
Melanotaenia pygmaea
The smallest member of the Melanotaenia genus, endemic to the Prince Regent River area in Western Australia. They are highly active, schooling fish known for their stunning iridescent blue and mauve coloration in males. Despite their small size, they require ample horizontal swimming space to accommodate their energetic nature.
Nothobranchius rachovii
A stunning annual killifish native to temporary floodplains in East Africa. Because their natural habitats dry up seasonally, they have a short lifespan (usually 8-12 months) and grow incredibly fast. They spawn by diving into soft substrate to bury their eggs, which then require a dry incubation period. Best kept in species-only setups with a soft soil or peat substrate.
Herotilapia multispinosa
Widely regarded as one of the most peaceful and beginner-friendly Central American cichlids. They are known for their vibrant gold, orange, and black coloration which intensifies during breeding. In the wild, they inhabit muddy, slow-moving waters and have specialized teeth for grazing on algae. While peaceful for a cichlid, they become aggressively territorial when spawning and their herbivorous diet means they will happily consume soft-leaved aquarium plants.
Epalzeorhynchos frenatum
A popular, active freshwater 'shark' (actually a cyprinid) known for its striking red fins contrasting with a dark or albino body. They are highly territorial bottom-dwellers. Only keep one per tank, as they are notoriously aggressive toward their own kind, other 'sharks' (like the Red Tail Shark), and similar-looking bottom feeders.
Channa bleheri
A strikingly colorful dwarf snakehead native to the Brahmaputra River basin. It is a subtropical species requiring a seasonal temperature drop (winter resting period at 14-18°C) to thrive long-term. As an obligate air-breather and notorious escape artist, a tight-fitting, heavy lid is absolutely mandatory. Highly predatory, it is best kept in a dedicated species tank or as a solitary bonded pair.
Planorbidae fam.
Ramshorn snails are highly adaptable, peaceful invertebrates named for their shells, which resemble a coiled ram's horn. They are excellent clean-up crew members that consume detritus, uneaten food, and soft algae without harming healthy plants. Because they are hermaphroditic and can self-fertilize, they breed prolifically if an aquarium is overfed.
Glossolepis ramuensis
The Ramu Rainbowfish is a beautiful, active schooling fish native to the Ramu River basin in Papua New Guinea. In the wild, they inhabit clear creeks with rocky and gravel bottoms. They are fast, active swimmers requiring plenty of lateral swimming space. Males develop stunning greenish-purple backs with orange stripes, while females remain silvery. Best kept in groups with a higher ratio of females to males.
Potamotrygon scobina
A relatively small freshwater stingray native to the Amazon basin. While smaller than other Potamotrygon species, it still requires massive aquariums with extremely strong filtration due to its high metabolism and extreme waste output. It is a benthic carnivore that needs a deep, fine sand substrate to bury itself and avoid scratching its soft underside. Warning: Possesses a venomous tail barb.
Piaractus brachypomus
A massive, extremely fast-growing freshwater fish closely related to the piranha, but with blunt, human-like teeth adapted for crushing nuts and seeds. While peaceful toward fish they cannot swallow, they are notorious 'tankbusters' that quickly outgrow standard home aquariums and require custom ponds or multi-thousand-liter setups.
Laetacara dorsigera
A peaceful and colorful dwarf cichlid native to the Amazon and Paraná River basins. Known for the stunning purple/red belly and face they develop, particularly when in spawning condition. Unlike many cichlids, they are relatively gentle and plant-safe, making them excellent centerpieces for community aquariums. They are exceptionally tolerant of cooler water temperatures.
Amphilophus labiatus
A massive, extremely aggressive Central American cichlid. Aptly named, the Red Devil is highly intelligent, interactive, and famous for 'glass-banging' at their owners. They are powerful diggers that will uproot plants and rearrange decor. Because of their sheer aggression and jaw strength, they are almost exclusively kept as 'wet pets' in solitary setups.
Microrasbora rubescens
A stunning but rare nano species endemic to Lake Inle, Myanmar. Unlike most rasboras that prefer soft acidic water, this species strictly requires harder, alkaline water (pH 7.5+) to thrive and display its vibrant orange-red coloration. They are peaceful, active schoolers that must be kept in large groups in planted aquariums.
Protomelas taeniolatus
A stunning and relatively peaceful Lake Malawi Haplochromine cichlid. Males develop breathtaking red and blue coloration, while females remain a camouflaged silvery-brown. Though considered a 'gentle Hap' compared to Mbuna, they are still large, active African Cichlids that require hard, alkaline water, plenty of swimming space, and rockwork.
Moenkhausia sanctaefilomenae
The Red Eye Tetra is a hardy, active schooling fish recognizable by the bright red upper half of its eye and a striking black and yellow band at the base of its tail. As a robust and highly adaptable species, it is excellent for beginners. However, they are highly active and can become 'fin nippers' if kept in groups smaller than 6 or in confined spaces.
Copadichromis borleyi
A popular African Cichlid from Lake Malawi belonging to the open-water Utaka group. Known for extreme sexual dimorphism, mature males display brilliant orange-red bodies with metallic blue heads, while females remain silver. They require hard, alkaline water, sandy substrates, and plenty of open swimming space.
Neolamprologus caudopunctatus
A small, spirited cichlid native to the transitional rocky-sandy shores of Lake Tanganyika. Recognizable by its pearly body, iridescent blue eyes, and striking orange/red dorsal fin margin. They are versatile breeders, utilizing both rock crevices and empty snail shells. While relatively peaceful for Tanganyikan cichlids, they fiercely defend their territory when spawning.
Caridina sp. Red Goldflake
The Red Goldflake Shrimp is a stunning but delicate freshwater invertebrate native to the ancient lakes of Sulawesi, Indonesia. It features a dark maroon base color heavily speckled with brilliant golden flecks. As a Sulawesi species, it strictly requires highly stable, warm, alkaline water with specific mineral content to thrive. They feed continuously on biofilm and algae. Highly sensitive, they are recommended only for advanced shrimp keepers.
Geophagus sp. 'Red Head Tapajos'
A stunning and relatively peaceful South American Eartheater, recently formally described as Geophagus pyrocephalus. They are named for the bright red/orange coloration that develops on the heads of mature adults. As 'eartheaters', they constantly sift substrate through their gills to find food, making fine sand an absolute requirement to prevent injury. They are social cichlids that must be kept in groups.
Geophagus steindachneri
A fascinating South American cichlid famous for its constant sand-sifting behavior to find food. They are maternal mouthbrooders. Unlike many large cichlids, they are relatively peaceful toward other species, making them excellent candidates for large community tanks, though conspecific males will clash.
