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.
Apistogramma cacatuoides
A highly popular and vibrant dwarf cichlid native to the Amazon basin. Named for the male's flamboyant, crest-like dorsal fin. They are cave-spawners that require a fine sand substrate (which they sift through their gills) and plenty of hiding spots. While generally peaceful in community tanks, they become fiercely territorial when breeding.
Ariopsis seemanni
A highly active, shark-like catfish that undergoes a dramatic physiological change during its life. While often sold as freshwater fish, juveniles require brackish water and adults MUST be transitioned to high-brackish or full marine conditions to survive and prevent disease. They are predatory and will eat any fish small enough to fit in their mouths. Caution: Their dorsal and pectoral spines are venomous.
Hyphessobrycon columbianus
A larger, deep-bodied tetra known for its striking metallic blue body and bright red fins. They are very active and can be somewhat boisterous. They are known to occasionally nip fins if kept in groups that are too small or in tanks that lack adequate swimming space.
Hypostomus plecostomus
A heavily armored, nocturnal catfish famous for eating algae. However, they grow incredibly large, produce massive amounts of waste, and frequently outgrow standard aquariums. They require driftwood in their diet for digestion. As they age, they may become territorial or develop a taste for the slime coat of slow-moving, flat-bodied tank mates.
Pterygoplichthys pardalis
One of the most widely sold (and misunderstood) fish in the aquarium trade. Often purchased as small 'algae eaters', Common Plecos grow into massive, heavy-waste-producing giants. They require driftwood for digestion and large aquariums. As they age, they may become territorial and lazy, sometimes latching onto flat-bodied fish (like Discus) to eat their slime coat.
Synodontis nigrita
A robust and adaptable African catfish often mistaken for the true Upside-Down Catfish (Synodontis nigriventris). Unlike its smaller cousin, S. nigrita grows quite large (up to 20-22cm) and adults rarely swim inverted. They are nocturnal scavengers that are generally peaceful towards larger tank mates, but their predatory nature means they will consume small schooling fish (like Neon Tetras) at night.
Rineloricaria eigenmanni
A highly distinctive, slender, and peaceful bottom-dwelling catfish from South America. Known for its extremely elongated tail and excellent camouflaging abilities. They are non-aggressive grazers that feed on biofilm, aufwuchs, and sinking foods. Their rigid, twig-like bodies mean they need broad, smooth resting places.
Polypterus endlicheri congicus
The Congo Bichir is a prehistoric-looking, bottom-dwelling monster fish and one of the largest species in the Polypteridae family. They are obligate air-breathers and ambush predators that will eagerly consume any tankmate small enough to fit in their surprisingly large mouths. Due to their massive adult size, they require extremely large custom aquariums, heavy filtration, and a tight-fitting lid to prevent escapes.
Tetraodon miurus
An ambush predator native to the Congo River basin. Affectionately known as the 'Potato Puffer' due to its lumpy, inactive appearance when buried. It requires deep, soft sand to bury itself and wait for prey. It is highly aggressive, strictly carnivorous, and must be kept solitary as it will bite or consume almost any other fish.
Phenacogrammus interruptus
A stunning, large schooling fish native to the Congo River basin. Known for their iridescent rainbow colors and active swimming behavior. Despite their size, they are notoriously peaceful and can be skittish, requiring ample swimming space, dim lighting or floating plants, and peaceful tank mates. Avoid keeping with fin-nippers.
Hypancistrus contradens
A striking, medium-sized pleco characterized by a pitch-black body covered in large white 'snowball' spots. Unlike common plecos, the Contradens (like most Hypancistrus) leans carnivorous and prefers meaty foods over algae. They require highly oxygenated, warm water with strong flow to mimic their native fast-flowing Venezuelan rivers.
Amatitlania nigrofasciata
One of the most ubiquitous and hardy cichlids in the hobby. Named for their black-and-white prison stripe pattern, Convicts are infamous for their intense aggression, especially when breeding (which they do readily). They are intelligent, wet pets that rearrange their tank décor constantly. Best kept in species-only tanks or with other robust Central American cichlids.
Trigonostigma hengeli
A small, peaceful, and highly active schooling fish known for the striking glowing orange or copper stroke above its thin black 'pork-chop' marking. Smaller and much more slender than the standard Harlequin Rasbora, they are perfect for planted nano aquariums. They must be kept in schools of at least 6 to feel secure and display their best colors.
Melanotaenia corona
A critically endangered and highly sought-after rainbowfish endemic to the Sermowai River in Northern New Guinea. Originally known from only two preserved specimens collected in 1911 above a waterfall, it has only recently been rediscovered and bred for the aquarium hobby. They feature distinct dark longitudinal stripes and dark fins with striking white margins. Like most rainbowfish, they are fast, active schoolers that require pristine, well-oxygenated water and ample open swimming space.
Melanotaenia duboulayi
A highly active, schooling freshwater fish endemic to eastern Australia, often considered the original 'Australian Rainbowfish' in the aquarium trade. Recognizable by a prominent crimson red spot on the operculum (gill cover) and striking silvery-blue to greenish bodies. They are peaceful but extremely vigorous swimmers, requiring plenty of horizontal swimming space and a tight-fitting lid to prevent jumping.
Loricaria sp. "Rio Atabapo"
An undescribed, highly sought-after whiptail catfish native to the blackwaters of the Orinoco basin. It gets its 'Crying' moniker from the striking dark parallel stripes running through its eyes. They are extremely peaceful, sedentary bottom-dwellers that require fine sand to partially bury themselves. Uniquely, males are paternal 'lip-brooders', carrying egg clusters on their specialized lower lips.
Nandopsis tetracanthus
A striking, highly aggressive predatory cichlid native to the rivers and lakes of Cuba. They are known for their spectacular black and white 'mosaic' or 'tiger' patterning, which becomes incredibly vivid during breeding. Best kept by experienced aquarists due to their extreme territoriality, potential size, and need for hard, alkaline water. They are also known to be naturally euryhaline, tolerating brackish conditions.
Atractosteus tristoechus
The Cuban Gar (Manjuarí) is a massive, ancient ambush predator native to the fresh and brackish waters of Cuba. It features a crocodilian snout, heavy armor-like scales, and a torpedo-shaped body. Due to its extreme adult size, it is strictly recommended only for expert aquarists with indoor ponds or enormous custom tanks. It will swallow any tank mate small enough to fit in its jaws, but generally ignores fish that are too large to eat.
Synodontis multipunctatus
A striking African catfish famous for its 'cuckoo' breeding strategy, where it sneaks its eggs into the clutches of mouthbrooding cichlids. They are highly active, social, and thrive in hard, alkaline water typical of Lake Tanganyika. They must be kept in groups to diffuse conspecific aggression and are best kept with Rift Lake cichlids.
Biotodoma cupido
A peaceful, mildly gregarious 'eartheater' cichlid native to the Amazon and Essequibo River basins. Known for the distinctive black teardrop marking behind their gills and subtle, iridescent pastel coloration. Unlike many South American cichlids, they are remarkably gentle and thrive in small shoals. They require excellent water quality and a soft sand substrate to exhibit their natural sifting behavior.
Amatitlania cutteri
A stunning, robust Central American cichlid known for its striking blue eyes, vertical barring, and metallic sheen. While generally considered less aggressive than its close cousin the Convict Cichlid, it is highly territorial during breeding. They form monogamous pairs and are excellent, albeit fierce, parents that will actively dig out spawning pits.
Cyprichromis leptosoma
A unique, pelagic (open-water) schooling cichlid endemic to Lake Tanganyika. Unlike rock-dwelling African cichlids, 'Cyps' live in massive shoals in the open water column where males display to females in spectacular 3D territories. They require very hard, alkaline water and a long tank (minimum 4 feet / 120cm) to accommodate their active swimming behavior.
Corydoras habrosus
A true dwarf Corydoras species, the Dainty Cory (Corydoras habrosus) is a highly active, peaceful bottom dweller. Unlike the Pygmy Cory (C. pygmaeus) which frequently swims in the mid-water column, the Habrosus stays true to typical Corydoras behavior by constantly sifting the substrate. They must be kept on fine sand to protect their delicate barbels and require a school of at least 6 to feel secure.
Pareutropius buffei
A highly active, diurnal schooling catfish native to West African rivers. Unlike most bottom-dwelling catfish, they continuously swim in the mid-to-upper water column. While often sold in the trade as 'P. debauwi', virtually all specimens are actually 'P. buffei' (distinguished by having three lateral stripes instead of one). They are peaceful, require highly oxygenated water with moderate flow, and absolutely must be kept in groups.
