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.
Uca sp.
Fiddler Crabs are semi-terrestrial invertebrates that absolutely require a specialized tank (paludarium) with access to dry land. They CANNOT survive fully submerged and will drown. Furthermore, they require brackish water for long-term survival, despite often being incorrectly sold as freshwater pets. They are social, highly active scavengers.
Dichotomyctere ocellatus
A small, highly intelligent, and interactive pufferfish known for the distinctive figure-eight pattern on its back. While often sold as freshwater fish, they strictly require a low-end brackish environment (Specific Gravity 1.005-1.008) for long-term health and a full lifespan. They are aggressive fin-nippers and strict carnivores that require hard-shelled foods (like snails) to keep their continuously growing teeth trimmed.
Dawkinsia filamentosa
The Filament Barb is a lively, active schooling fish native to the rivers of southern India. They are known for their shimmering bodies, distinct black caudal spot, and preference for open swimming space. Due to their size and high energy, they require large aquariums with robust filtration. They can be fin-nippers if kept in too small of a school and may nibble on soft-leaved plants.
Monodactylus argenteus
The Silver Mono, or Finger Fish, is a stunning, fast-moving schooling fish known for its shiny, diamond-shaped body. They are euryhaline; juveniles inhabit freshwater or brackish estuaries, but adults require high-end brackish or full marine setups to thrive. They are active, voracious eaters that must be kept in groups to curb fin-nipping and internal aggression.
Mastacembelus erythrotaenia
The Fire Eel is a stunning, large species of spiny eel native to Southeast Asia, known for its brilliant red lateral stripes and highly interactive, 'dog-like' personality with owners. As a true 'monster fish', it requires massive aquariums. A soft sand substrate is absolutely mandatory, as they will burrow and suffer lethal bacterial infections from scratching themselves on gravel. They are notorious escape artists and will eat any fish small enough to fit in their mouths.
Hyphessobrycon flammeus
The Fire Tetra (commonly sold as the Flame or Von Rio Tetra) is a peaceful, schooling nano fish originating from the coastal rivers of Brazil. They are prized for their striking two-toned appearance, which transitions from silver/yellow at the head to a vibrant fiery red at the tail. Hardy and adaptable, they make an excellent choice for planted community aquariums, though they are unfortunately considered endangered or possibly extinct in the wild due to habitat loss.
Thorichthys meeki
A popular Central American cichlid famous for the bright red coloration on its throat and belly, which it flares to intimidate rivals. They are earth-eaters, constantly sifting sand for food. While territorial, especially during breeding, they are relatively peaceful for a cichlid of their size compared to larger Central American counterparts.
Desmopuntius pentazona
A small, peaceful, and beautifully colored schooling cyprinid native to the blackwater peat swamps of Southeast Asia. Often confused with the much more aggressive Tiger Barb, the Five Banded Barb is entirely peaceful and will not nip fins. They are somewhat shy and require a well-planted tank with dim lighting or floating plants to feel secure and show their best reddish-orange colors.
Hyphessobrycon heterorhabdus
A peaceful, active schooling fish native to the Amazon basin. It is commonly called the 'Belgian Flag Tetra' due to the distinctive tricolor lateral stripe (black, red, and yellowish-white) running along its side. They are an excellent community fish that thrives in planted aquariums with soft, slightly acidic water. Like most tetras, they must be kept in groups to feel secure and display their best colors.
Corydoras robineae
The Flagtail Corydoras is a striking and highly sought-after bottom dweller native to the Rio Negro basin. Characterized by the distinct black and white horizontal stripes on its caudal fin, it requires a soft sand substrate to protect its delicate barbels while foraging. Like all Corydoras, it is a highly social schooling fish and must be kept in groups to feel secure and display natural behaviors.
Semaprochilodus insignis
A large, highly active South American river fish famous for its vividly striped tail and prolific algae-eating habits. They are a staple 'cleaner' in large monster fish setups alongside Arowanas and Stingrays. While peaceful towards other large species, they are fiercely intolerant of their own kind unless kept in large shoals. They are notorious plant destroyers.
Panaqolus albomaculatus
A striking, small loricariid known for its vibrant yellow/white stripes on a dark body. Note: The scientific name 'P. albomaculatus' correctly refers to the Mustard Spot Pleco (LDA31), while the true Flash Pleco is 'P. albivermis'. Both share identical husbandry. As xylophagous (wood-eating) catfish, they absolutely require real driftwood in the aquarium to digest properly and will produce copious amounts of sawdust-like waste.
Chindongo flavus
An aggressive but striking Mbuna cichlid endemic to Lake Malawi (specifically around Chinyankwazi Island). Formerly classified as Pseudotropheus, they inhabit rocky areas and graze on aufwuchs (algae and microorganisms). They require hard, alkaline water, complex rockwork for territories, and are best kept in harems to manage their extreme conspecific aggression.
Jordanella floridae
A robust, deep-bodied killifish native to Florida. Unlike most killifish, they are primarily herbivores and are renowned for their ability to eat Hair Algae and sometimes Black Beard Algae. They are sub-tropical and thrive in unheated aquariums. They can be fin-nippers, especially if underfed or kept with long-finned tank mates.
Lepisosteus platyrhincus
A prehistoric, heavily armored ambush predator native to the southeastern United States. They possess an elongated, torpedo-like body and a beak filled with sharp teeth. As an apex predator, they will consume any tank mate that fits in their mouths, but are generally peaceful toward fish too large to eat. They require massive aquariums and a secure, weighted lid due to their powerful jumping capability.
Potamotrygon schroederi
A stunning, large-growing freshwater stingray native to the Rio Negro and Orinoco basins. They feature intricate rosette or flower-like patterns. As apex predators, they require massive aquariums, exceptional biological filtration due to extreme bioloads, and a fine sand substrate to prevent injury to their soft bellies. They possess a venomous tail barb and must be handled with extreme caution.
Hybrid cichlid (Amphilophus cross)
A man-made hybrid cichlid famous for its vibrant colors, extreme interactive personality, and the large nuchal hump (kok) on its head. They are incredibly aggressive 'wet pets' that will attack hands, tank mates, and equipment. They have a massive bioload, dig constantly, and must almost always be kept completely alone.
Melanotaenia sexlineata
A brilliantly colored, peaceful dwarf rainbowfish native to the upper Fly River system in Papua New Guinea. Recognized by its golden-turquoise sheen, distinctive horizontal stripes, and sometimes bright pink lips. Being an exceptionally active shoaling species, they require significant lateral swimming space despite their small size.
Epalzeorhynchos kalopterus
A striking, torpedo-shaped bottom dweller often confused with the Siamese Algae Eater. While they eat some algae when young, adults are primarily omnivores that become notoriously territorial and aggressive, especially towards their own kind, similar-looking fish, and other bottom dwellers. They are best kept as a single specimen in a community of mid-to-top swimming fish.
Craterocephalus stercusmuscarum
The Flyspeck Hardyhead is an active, slender schooling fish native to the freshwater streams and lakes of Australia. Named for the distinct rows of tiny black dots (resembling fly specks) covering its golden-bronze body, it is a highly peaceful species. They are excellent for community tanks, requiring plenty of swimming space, and offer the unique benefit of constantly grazing on algae and aquatic insects.
Pseudomugil furcatus
A highly active, nano shoaling fish native to Papua New Guinea. Recognized by their striking blue eyes and energetic swimming patterns. They are peaceful but require open horizontal swimming space and the company of their own kind to thrive. Due to their short lifespan (2-3 years), they mature quickly and display near-constant courtship behavior.
Aulonocara hansbaenschi
A stunning Lake Malawi Peacock cichlid known for the male's metallic blue body and vibrant red/orange flush behind the gills. Like all Aulonocara, they are benthivores (sand-sifters) that hunt small invertebrates using enlarged sensory pores on their lower jaw. They require hard, alkaline water and a fine sand substrate to exhibit natural behaviors without damaging their gills.
Fossorochromis rostratus
A massive, highly active Haplochromine cichlid from Lake Malawi, famous for its unique defense mechanism: diving headfirst and burying itself completely in the sand when startled. Due to its large adult size and open-water swimming behavior, it requires a huge aquarium with fine sand substrate.
Pterophyllum scalare
The most iconic South American Cichlid, known for its distinct arrowhead shape and majestic fins. While domestic strains are hardy, they remain cichlids: they are semi-aggressive predators that will eat any fish small enough to fit in their mouths (like Neon Tetras). They form loose shoals as juveniles but pair off and become territorial as they mature. Height is more important than length for this species.
