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.
Anomalochromis thomasi
A peaceful, colorful dwarf cichlid from West Africa. Unlike many cichlids, it is plant-safe and generally suitable for community tanks. It is famous in the hobby as an efficient biological control for pest snails.
Pantodon buchholzi
A fascinating, prehistoric-looking surface dweller native to the slow-moving waters of West Africa. They are strictly top-dwelling ambush predators with a completely flat back and upturned mouth designed to hunt insects and small fish. A tight-fitting lid is absolutely mandatory as they are exceptional jumpers capable of gliding above the water.
Hemichromis bimaculatus
A strikingly beautiful but notoriously aggressive West African riverine cichlid. Unlike the alkaline-loving Rift Lake cichlids (e.g., Mbuna), Jewel Cichlids prefer neutral, softer water parameters. They are renowned for their brilliant red breeding dress and iridescent blue spots, but also for their extreme territoriality, especially when forming pairs and spawning. They are avid diggers and will uproot most plants.
Protopterus annectens
An ancient, fascinating oddball fish capable of surviving droughts by aestivating in mud cocoons. It is an obligate air-breather with a powerful bite. Highly predatory and completely intolerant of tank mates, it should be kept strictly solitary. Requires a heavy, secure lid as they are notorious and powerful escape artists.
Apistogramma agassizii
A stunning South American dwarf cichlid known for its distinct spade-shaped tail and brilliant color morphs. They are bottom-dwelling micro-predators that sift sand for food. While generally peaceful in community tanks, they are highly territorial when breeding. They thrive in soft, acidic blackwater conditions.
Caridina multidentata
A highly popular, industrious freshwater shrimp renowned for its unmatched algae-eating abilities. Popularized by aquascaper Takashi Amano, they are significantly larger and hardier than most dwarf shrimp (like Cherry Shrimp). They are notorious food-thieves during feeding time and excellent escape artists, requiring a tight-fitting lid. Their larvae require saltwater to develop, so they will not overpopulate in a freshwater aquarium.
Monocirrhus polyacanthus
A master of camouflage that perfectly mimics a dead leaf drifting in the water. This species is an extreme ambush predator with a protruding jaw that can swallow prey up to 75% of its own size. It is a 'specialist' species because nearly all specimens require live food (small fish/shrimp) and refuse dry or frozen foods. Requires acidic, blackwater conditions and zero flow.
Colomesus asellus
One of the few truly freshwater, community-safe pufferfish. Native to the Amazon basin, these energetic swimmers are known for their bumblebee-like stripes and erratic swimming patterns. Unlike most puffers, they are social and prefer to be kept in groups. CRITICAL WARNING: This species has the fastest-growing teeth of any puffer. They REQUIRE a daily diet of hard-shelled foods (snails, clams, crustaceans) or they will require manual dentistry (trimming) to prevent starvation.
Pomacea maculata
One of the largest freshwater snails in the world, capable of reaching the size of a baseball or larger. Unlike the popular 'Mystery Snail' (Pomacea bridgesii) which is generally plant-safe, Pomacea maculata is a voracious herbivore that will systematically devour almost any live aquarium plant. They require heavy filtration due to their massive waste output and hard, calcium-rich water to prevent shell deterioration.
Clea helena
A highly effective and popular carnivorous freshwater snail used primarily for pest snail control. They actively hunt and consume smaller snails like bladder, ramshorn, and pond snails. Featuring a striking yellow and dark brown spiraled shell, they are a functional and attractive addition to aquariums. Unlike many aquatic snails, they are not hermaphroditic and reproduce quite slowly.
Melanochromis auratus
The Auratus Cichlid is a stunning but notoriously aggressive Mbuna from Lake Malawi. They exhibit extreme sexual dimorphism. They are strictly rock-dwellers that graze on algae (aufwuchs). Due to their hyper-aggressive nature, they must be kept in species-only or carefully managed, overstocked Mbuna setups with a strict harem ratio (1 male to several females) to disperse aggression.
Balantiocheilos melanopterus
Despite its name, the Bala Shark is a peaceful, schooling cyprinid. They are extremely active, fast swimmers that grow very large and startle easily. They are notorious for injuring themselves by crashing into the aquarium glass if kept in small tanks or easily spooked. They must be kept in groups and eventually require massive, custom-sized aquariums.
Atyopsis moluccensis
A large, completely peaceful freshwater filter-feeding shrimp. They use specialized fan-like appendages to catch microorganisms and fine food particles from the water column. They require an established aquarium with moderate to high water flow and tall resting places (like driftwood) directly in the current.
Toxotes jaculatrix
Famous for their ability to shoot down insects with a precise jet of water. As surface-dwelling predators native to mangrove estuaries, they require hard, brackish water to thrive long-term. They have a high prey drive and will eat any fish small enough to fit in their mouths. A tight-fitting lid is absolutely mandatory as they are exceptional jumpers.
Nannostomus beckfordi
A peaceful, slender schooling fish native to the sluggish rivers and swamps of South America. They are famous for the males' harmless but spectacular lateral sparring displays. They require heavily planted aquariums with gentle flow and make excellent tank mates for other peaceful, soft-water species. A tight-fitting lid is essential as they are known to be proficient jumpers.
Caridina cantonensis
A sensitive, highly prized dwarf shrimp species known for its vivid red/white or black/white banding. Unlike the hardy Cherry Shrimp (Neocaridina), Bee Shrimp require cool, soft, acidic water and typically require active buffering soil to thrive. They are peaceful grazers perfect for specific biotope setups.
Betta splendens
The Siamese Fighting Fish is an aquarium icon known for its labyrinth organ (allowing air breathing) and vivid colors. While hardy, they require heated, filtered water (24-30°C). Males are solitary and fiercely territorial. Females are generally less ornate but can be kept in 'sororities' with strict precautions (minimum 5 females in 75L+).
Apteronotus albifrons
A fascinating nocturnal predator native to the Amazon basin. It lacks a dorsal fin and moves via a continuous undulating ventral fin, allowing it to swim backwards as easily as forwards. It generates a weak electrical field to navigate and hunt in the dark. Scaleless and highly sensitive to medications, it requires smooth hiding places (like PVC pipes or smooth driftwood). Will consume any fish small enough to fit in its surprisingly large mouth.
Hyphessobrycon herbertaxelrodi
A peaceful, active schooling fish native to the Paraguay basin. Known for its striking contrast of a dark black lateral stripe underneath a glowing iridescent white/green-gold stripe. Excellent for community aquariums, particularly in planted setups or blackwater biotope tanks with subdued lighting.
Colossoma macropomum
The Black Pacu (Tambaqui) is a massive, incredibly fast-growing Amazonian fish. Closely related to Piranhas, they possess crushing, human-like teeth evolved for cracking nuts and seeds. Due to their enormous adult size (often exceeding 3 feet and 60 lbs) and extreme bioload, they are completely unsuitable for standard home aquariums and require colossal custom tanks or heated indoor ponds.
Gymnocorymbus ternetzi
A very hardy, deep-bodied schooling tetra native to South America. They are incredibly popular for beginners but have a reputation as fin-nippers if kept in too small a group. A proper school disperses their internal bickering and largely prevents them from harassing other tank mates.
Physella acuta
A tiny, fast-moving freshwater snail almost universally introduced accidentally via live aquarium plants. While frequently labeled a 'pest' due to their rapid, prolific reproduction, they are actually an excellent cleanup crew. They consume algae, uneaten food, and decaying plant matter without harming healthy plants. They are hermaphroditic and can self-fertilize, meaning a single snail can start a massive colony.
Hyphessobrycon erythrostigma
A relatively large, deep-bodied tetra known for the distinctive bright red spot on its flank resembling a bleeding heart. They are active schoolers that require plenty of swimming space. While generally peaceful, they can become fin-nippers if kept in numbers fewer than 6 or in an undersized aquarium.
Astyanax mexicanus
A fascinating, totally blind species originating from limestone caves in Mexico. They are born with eyes that degenerate as they grow. Navigating via their highly sensitive lateral line, they are extremely active and constantly scavenge for food. Best kept in a species tank or with fast-moving, short-finned fish, as their erratic swimming and feeding style can result in accidental fin-nipping of slow tank mates.
