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.
Polypterus senegalus
A fascinating, prehistoric-looking predatory fish often called the 'Dinosaur Eel'. They possess a modified swim bladder acting as a lung and must have access to the surface to breathe. Though peaceful with large, deep-bodied tank mates, they are strictly carnivorous and will consume any fish or invertebrate that fits in their mouths. Excellent escape artists; a heavy, tight-fitting lid is mandatory.
Chilatherina sentaniensis
A critically endangered and highly active shoaling fish endemic to Lake Sentani in Papua, Indonesia. Known for their energetic, almost chaotic swimming patterns and ravenous feeding habits. While rarely seen in the general trade, they are highly prized; males develop spectacular blood-red to pinkish hues and arched backs as they mature. Requires a large aquarium with significant open swimming space and clean, oxygen-rich water.
Glossolepis multisquamata
The Sepik Rainbowfish, also known as the Rosy Rainbowfish, is a vibrant schooling fish native to the floodplains, swampy lagoons, and slow-moving rivers of New Guinea. They are highly active swimmers that display stunning metallic and red coloration. They thrive in densely planted aquariums with ample open swimming space and require a group to feel secure and display their best colors.
Hyphessobrycon eques
A striking, deep-red schooling fish known for its highly active nature. While hardy and beautiful, Serpae Tetras are notorious fin-nippers. This behavior is usually localized within their own pecking order if kept in large enough schools (8+), but they should never be housed with slow-moving or long-finned tank mates like Bettas, Angelfish, or Gouramis.
Heros severus
Severums are large, deep-bodied South American cichlids often called the 'Poor Man's Discus'. They are relatively peaceful for their size compared to other large cichlids, but they are notorious plant destroyers with a highly herbivorous diet. They require spacious aquariums with excellent filtration.
Neolamprologus multifasciatus
The smallest known cichlid in the world, endemic to Lake Tanganyika. They live, breed, and seek refuge in empty snail shells. They form highly entertaining, constantly digging colonies where multiple generations live together. Sand substrate and an abundance of empty shells (such as escargot shells) are strictly required for their survival and natural behavior.
Pangasius micronemus
A massive, highly active riverine catfish native to Southeast Asia. Like its cousin the Iridescent Shark, it is a nervous and skittish swimmer prone to panicking and injuring itself on tank glass. Due to its enormous adult size of up to 1 meter (39 inches), it is strictly suited for only the largest custom aquariums, indoor ponds, or public aquaria. It is an opportunistic predator that will consume any tank mate small enough to fit in its large mouth.
Lepisosteus platostomus
A primitive, highly predatory North American 'monster fish' with a long, tooth-filled snout and armor-like ganoid scales. They are ambush predators that require massive aquariums or indoor ponds. They breathe atmospheric air via a modified swim bladder. Due to their size and predatory nature, they will consume any tank mate small enough to fit in their mouths.
Scaphirhynchus platorynchus
The Shovelnose Sturgeon is a prehistoric-looking, highly active cold-water fish native to the Mississippi and Missouri river basins. They are bottom-dwelling predators that sift through sand for invertebrates and small fish. They require massive aquariums or indoor ponds with heavy filtration, high oxygenation, and strong water flow to mimic their natural riverine habitats.
Crossocheilus oblongus
Famous for being one of the few freshwater fish that actively consumes Black Beard Algae (BBA). A torpedo-shaped, active bottom-to-midwater swimmer native to Southeast Asian streams. True Siamese Algae Eaters feature a distinct black horizontal stripe that extends all the way through the tail fin. As they mature, they can become lazy, preferring prepared foods over algae, and may occasionally chase other bottom dwellers.
Datnioides pulcher
The true Siamese Tiger Fish is a massive, highly sought-after, and critically endangered apex predator native to Southeast Asian river basins. Known for its striking wide black vertical bands against a gold body. It is a strictly freshwater species. Highly predatory, it will consume any fish that fits into its large protrusible mouth, but is generally peaceful with tank mates that are too large to eat.
Osteoglossum bicirrhosum
A massive, prehistoric-looking surface predator native to the Amazon Basin. Known for their metallic silver scales and incredible jumping ability (used in the wild to catch insects from low-hanging branches). They grow exceptionally fast and require gigantic aquariums. They will consume any tank mate small enough to fit into their large, trapdoor-like mouths.
Datnioides polota
A striking predatory fish known for its deep body and tiger-like stripes. Unlike other Datnoids, the Silver Datnoid is euryhaline and naturally inhabits estuaries; while it can survive in freshwater, it thrives in light brackish conditions. They are ambush predators with highly protrusible jaws capable of swallowing surprisingly large prey.
Metynnis argenteus
A large, peaceful schooling characin renowned for its laterally compressed, coin-like silver body. They are notorious herbivores that will devour almost any live plant in the aquarium. Highly skittish, they are known to dart rapidly when startled, requiring ample unobstructed swimming space and a tight-fitting lid.
Crossocheilus reticulatus
A highly active, fast-swimming cyprinid from Southeast Asia renowned for its voracious appetite for nuisance algae, including Black Beard Algae (BBA). They are distinguished from the Siamese Algae Eater by a net-like (reticulated) scale pattern and a distinct black spot at the base of the tail. They require highly oxygenated, fast-flowing water. Due to their strict social hierarchy, it is highly recommended to keep them entirely solitary or in a group of 5 or more; keeping 2 to 4 often results in the subdominant fish being bullied to death.
Gasteropelecus sternicla
A uniquely shaped characin with a deep, keeled belly adapted for surface dwelling. Known as 'flying fish', they possess powerful pectoral fins used to leap from the water to catch insects or escape predators. A tight-fitting lid with absolutely no gaps is mandatory. They are peaceful schooling fish that require open surface swimming space and floating plants to feel secure.
Semaprochilodus taeniurus
A large, active riverine species famous for its striking striped tail and ability to consume massive amounts of algae. Commonly kept as a 'cleanup crew' in monster fish setups (with Arowanas or large Cichlids). They are peaceful towards other species but highly intolerant of their own kind unless kept in large shoals to disperse aggression.
Chilatherina crassispinosa
An active, schooling rainbowfish native to the clear, fast-flowing streams of Northern New Guinea. Known for their energetic swimming patterns and silvery bodies, they require long aquariums with strong water flow and high dissolved oxygen. Best kept in groups of 6 or more.
Datnioides polota
A large, predatory, and fascinating species widely known in the hobby as the 'American Tigerfish' (AT) or Silver Datnoid. Note: Scientific consensus now recognizes Datnioides polota as the valid name, with D. quadrifasciatus often used as a synonym. Naturally found in brackish estuaries and river mouths, they adapt to freshwater but thrive in hard, alkaline, light-brackish conditions. They are aggressive predators and best kept singly or in very large groups.
Hasemania nana
The Silvertip Tetra is an energetic, hardy schooling fish native to the blackwater creeks of Brazil. Uniquely for tetras, they lack an adipose fin. Males are a striking deep copper/gold, while females are paler yellow, but both feature the eponymous bright silver-white tips on their fins. They are extremely active, boisterous swimmers and can be prone to fin-nipping if kept in too small a group or with slow-moving tank mates.
Distichodus sexfasciatus
The Sixbar Distichodus is a massive, highly active African river fish. While sold as brightly colored, tiger-striped juveniles, they grow into enormous grayish adults. They are infamous for consuming all aquatic vegetation and becoming intensely territorial toward conspecifics as they age. They require enormous aquariums and robust tank mates.
Yasuhikotakia morleti
A strikingly patterned but notoriously aggressive loach from the Mekong basin. Named for the prominent black stripe running down its back, the Skunk Botia is highly territorial and prone to nipping the fins of slow-moving or long-finned tank mates. They are exceptionally efficient snail hunters but must be kept in groups of 5 or more to disperse their complex, hierarchical aggression. They require a soft, sandy substrate to protect their sensitive barbels from damage.
Corydoras arcuatus
A charming and peaceful bottom-dwelling catfish native to the Amazon basin, easily identified by the dark, skunk-like stripe running from its mouth along the ridge of its back to its tail. Like all Corydoras, they are obligate shoaling fish that require a group of conspecifics to feel secure. Fine sand substrate is mandatory to prevent damage to their delicate sensory barbels.
Melanotaenia gracilis
A streamlined and highly active schooling fish native to the Drysdale River system in Western Australia. Known for its slender body and subtle pastel colors with red-edged fins. They are peaceful but their fast, boisterous swimming can outcompete slower, shy fish for food. Needs a long aquarium with plenty of open swimming space.
