Explore all oddballs in our database. Browse detailed care guides, compatibility information, and species data to find the perfect fish for your aquarium.
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.
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.
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.
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.
Chitala ornata
A massive, nocturnal predator native to Southeast Asia, widely known for the distinct row of ocellated spots above its anal fin. While sold as small silvery cute juveniles, they grow incredibly fast into nearly 1-meter giants that require immense aquariums. They are obligate carnivores and will eat any fish small enough to fit in their large mouths. They are shy during the day and require large hiding tubes or caves.
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.
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.
Datnioides microlepis
A massive, deep-bodied ambush predator highly prized by monster fish keepers for its striking black and gold 'tiger' stripes. Native to the freshwater rivers of Southeast Asia, they possess huge mouths and will consume any fish small enough to fit. They are notoriously shy when young but grow into bold, impressive centerpieces. Due to intense conspecific aggression, they should be kept entirely solitary or in groups of 4 or more to disperse bullying.
Monodactylus sebae
A striking, deeply compressed (diamond-shaped) schooling fish native to the estuaries and mangroves of West Africa. While juveniles are frequently found in freshwater or light brackish water, adults strictly require high brackish to full marine conditions to survive long-term. They are hyperactive, grow extremely tall, and require massive, open aquariums to accommodate their schooling nature.
Potamotrygon motoro
A spectacular but highly demanding freshwater stingray native to South America, instantly recognizable by its orange-spot 'peacock' pattern. They are massive, heavy-polluting predators that require huge aquariums with pristine water quality. A soft sand substrate is absolutely mandatory to prevent severe bacterial infections on their delicate underbellies. Note: They possess a venomous tail stinger.
Gnathonemus petersii
A highly intelligent, nocturnal oddball native to African rivers. They navigate, communicate, and hunt using a weak electrical field generated from a specialized organ in their tail and a highly sensitive 'trunk' (a specialized chin appendage). A soft sand substrate is absolutely mandatory to prevent their trunk from being damaged by abrasion. They are notoriously aggressive toward conspecifics unless kept in very large shoals in massive aquariums.
Erpetoichthys calabaricus
An ancient, eel-like species from West Africa closely related to Bichirs. They are famous for their snake-like appearance and gentle nature. Unlike Bichirs, Ropefish are social and prefer to be kept in groups. They are nocturnal hunters using smell to find food. WARNING: They are legendary escape artists; a tight-fitting lid without even the smallest gap is 100% mandatory.
Scatophagus argus
A highly active, large schooling fish found in Indo-Pacific estuaries. 'Scatophagus' translates to 'dung-eater', pointing to their voracious, omnivorous appetite and the massive amount of waste they produce. While juveniles can tolerate light brackish water, adults strictly require heavy brackish to full marine conditions. They possess mildly venomous dorsal spines.
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.
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.
Mastacembelus armatus
A massive, predatory spiny eel known for its distinctive tire-track patterning. They are nocturnal bottom-dwellers that love to burrow. A soft sand substrate is absolutely mandatory; sharp gravel will severely damage their skin and lead to fatal bacterial infections. While peaceful to fish too large to swallow, they are highly efficient predators that will eat any tank mate that fits into their surprisingly large mouths. Excellent escape artists; a heavy, tight-fitting lid is required.
