Bichirs (Sometimes called dinosaur eels) are true living fossils and some of the most unusual fish in the aquarium hobby.
Bichirs make up the Polypteridae family and are found primarily in northeast Africa along the Nile River and its associated tributaries.
They have a good sense of smell and can also sense electricity in the water. They have Lorenzini blisters which are small organs that can pick up electricity from other animals in the water.
Bichir’s lungs are a bit different than the lungs of other fish. A Bichir’s lungs are more like a sac than a mass of tissue. There doesn’t seem to be much of an advantage of one over the other, it’s just the way they evolved.
If you have bichirs in your aquarium, here is a list of the best 10 compatible tank mates for them:
1. Peacock Bass
- Scientific nickname: Cichla ocellaris
- Root: South America
- Size: 24-30 inches
- Temperament: gentle; Predator
Despite its nickname, the Peacock Bass is in fact a large South American cichlid. However, they have been introduced in South Florida and Puerto Rico, so you can identify one in the United States.
Like most large cichlids, the Peacock Bass is neither territorial nor digs. They are open and ambush liquid predators that live as long as the North American seabass.
Their large mouths allow them to swallow massive prey, however larger types of Bichir, such as the Ornate Bichir (Polypterus ornatipinnis), are safe.
Considering how big they grow, you will need a container of at least 200 gallons for an adult peacock bass. However, they are some of the most enjoyable fish you can have. They recognize their owners and will splash for treats and show aggression if different people approach the tank!
2. Oscar
- Scientific nickname: Astronotus ocellatus
- Root: South America
- Size: 12-14 inch
- Temperament: Semi-aggressive
Oscars are probably the most widespread large cichlids in the world and for good reason. They are so strong, beautiful, nice, and come in a variety of attractive shades of red. While they are not as big as Peacock Bass, Oscars are still big predators, so be careful in the period when you treat them with lesser Bichirs.
However, any of the medium to large types make excellent container dwellers.
As native South Americans, the Oscars choose a smooth and slightly acidic liquid (pH 5.5-6.5). However, they have been raised in containers for decades and will indeed thrive on alkaline demand.
Oscars should receive a mix of fresh items, as well as earthworms and feeder fish along with high-condition protein-rich pellets. The bichir consumes exactly the same. They are not surface feeders, however, so you may need to apply feeding tongs to make sure your Oscar doesn’t greedily devour everything.
3. Black Ghost Knife Fish
- Scientific nickname: Apteronotus albifrons
- Root: South America
- Size: up to 16 inches
- Temperament: Shy; Territorial
Black ghost knife fish make excellent tank mates for bichirs despite being underwater inhabitants. While they are predators, black ghosts have smaller mouths and are rarely a threat to any fish close to their size.
They choose to hunt worms and lesser fish. In terms of temperament, Black Ghost Knifefish are quite unusual. They are mostly nocturnal and choose to remain hidden during the day in a cave or under a driftwood overhang. As a result, they are quite shy; however, they are so territorial as to aggressively defend their lair from intruders.
PVC pipes are the best hiding places for them as they block light and help partially isolate your knife fish from electrical signals from passing fish.
Despite their nocturnal habits and poor eyesight, black ghosts are electric fish! They generate a weak current that then helps to navigate in total darkness and find sleeping fish hidden in the rocks and grow.
4. Elephant Nose Fish
- Scientific nickname: Gnathonemus petersii
- Root: West Africa
- Size: 9 inch
- Temperament: Peaceful
Another African underwater inhabitant that gets along well with Bichirs is the Elephant nose fish. They are not hard to find commercially sold as 3-4 inch juveniles. As adults, they are medium in size and need at least 55 gallons of territory.
While they are carnivores, their small mouths ensure that only the smallest fish are at risk of being eaten. Elephant nose fish are also weakly electric, applying a specialized muscle in the tail to generate a bodily current.
They have electroreceptors in their skin and “trunk” to detect worms and different elements hidden in the substrate.
Being diggers, they must be given sandy or silty substrates, as small stones can damage their delicate “noses”.
While peaceful, elephant nose fish are just as territorial and intolerant of a different one in anything but the largest fish tanks or aquariums. Interestingly, the elephant nose fish and the different mormyrid fish have the highest brain-to-body ratio of all fish; equivalent to a human! How well this translates to superior intelligence is still being studied.
5. The Blind Cave Tetra
- Scientific nickname: Astyanax mexicanus
- Root: Texas and Mexico
- Size: 4-5 inch
- Temperament: Semi-aggressive; Teaching
In the period when minor species are treated, as well as the Senegalese bichir (Polypterus senegalus), large tetras are excellent tank mates for them.
The Blind Cave Tetra is a fascinating type from North America that normally spends its entire life underground. As a result, they have evolved over thousands of years from trapped Mexican tetras.
The cave form lost its eyes and pigmentation as one and the other was unnecessary. The blind form relies exclusively on smell and the sensitive lateral line to detect movement and renewal in fluid pressure.
Blind Cave tetras are on the larger side and can rise up to 5 inches. Considering that they do not have eyes, they are active during one and the other during the day and night. Small fish can end up being bitten while sleeping, however, the well-armed Bichir is too big and difficult to be one and the other for them.
6. Blue Acara
- Scientific nickname: Aequidens pulcher
- Root: South America
- Size: 6-8 inches
- Temperament: Peaceful
Green Terrors can be a bit excessive for Bichirs, especially in the breeding season. However, the Blue Acara is a lesser, gentler relative that is much better suited.
Acaras have an excessively deep body to be eaten, but they are short-tempered.
Blue acaras are good enough for digging, plus they’re pretty gentle on crops. In the breeding season, they will increase their cichlid-style aggression, so make sure your container is at least 55 gallons in proportion to provide new parents lttle room.
Recently, an electric blue color transformation has also spread extremely widely. Like most highly inbred fish, they tend to be more sensitive to abrupt changes in fluid conditions. So add them to mature and stable fish tanks or aquariums.
7. Leopard Ctenopoma
- Scientific nickname: Ctenopoma acutirostre
- Root: Congo River, Africa
- Size: 6 inch
- Temperament: Gentle; Predator
The leopard ctenopoma is as well known as the leopard bush fish or the leopard leaf fish. They belong to a family of fish recognized as the climbing perch since few of their relatives will leave the liquid for short distances applying their labyrinthine organ to breathe air.
Ctenopomas are ambush predators that apply their camouflage pattern to blend in with dappled shadow in thick undergrowth. So far, a properly sized fish passes close to them, striking, exposing a suddenly massive mouth outward to suck on its prey.
Like the equatorial African fish, Leopard Ctenopoma chooses a smooth, slightly acidic liquid and an elevated climate (77-84F).
In addition to their Asian cousins, Gourami and Betta fish, Ctenopoma are bubble nest builders and care for their eggs and fry for an extended period.
8. African Butterfly Fish
- Scientific Nickname: Pantodon buchholzi
- Root: West Africa
- Size: 5-6 inches
- Temperament: Peaceful, Predatory
Surface-dwelling fish are some of the best tank mates for predatory bichirs. African butterfly fish are relatives of Arowana with such unique habits. They mimic fallen foliage and debris while waiting for small fish and downed insects to drift closer.
African butterfly fish are also highly capable jumpers, so make sure your cap is as secure! As predators are very sensitive to movement, it is very difficult to train them into pellets or flakes. You should feed them live Guppies, Tubifex feeders, and specifically small insects as well as crickets.
Be sure to treat them with Minor Bichir, as the larger types may try to consume them.
9. Black Shark
- Scientific Nickname: Labeo chrysophekadion
- Root: Southeast Asia
- Size: up to 24 inches
- Temperament: Semi-aggressive
Freshly liquid sharks are not true sharks other than looking so identical. Most are on the peaceful side, however, the Black Sharkminnow is somewhat aggressive.
As long as you provide one and the other, it and your Bichir an area to hide disagreements should be rare.
Black sharks are also omnivores and love soft grows and parboiled vegetables to gnaw along with prepared flakes and pellets. In fact, they rise higher than most Bichir and have a very deep body.
Your fish tank or aquarium should be at least 200 gallons in volume for this stately cyprinid. Considering that they are almost exclusively underwater inhabitants, any peaceful container that lives in the middle to the upper liquid column is safe, including silver dollars and Arowanas.
10. Hoplo Catfish
- Scientific nickname: Megalechis thoracata
- Root: South America
- Size: 8 inch
- Temperament: Peaceful
Hoplo catfish are some of my favorite underrated types of fish. These natives of South America belong to the same family as the large corydoras.
However, they grow much larger, making them excellent tank mates for predatory Bichir. Hoplo catfish are well armored to withstand the occasional bite from an aggressive Bichir or Cichlid. And just as much as their Corydora cousins are so active, patrolling every layer of the liquid column in search of food.
Considering that you will be treating them with larger fish, make sure your mix in smaller pellets and frozen flour is suitable for smallmouth Hoplo catfish.
They are also good nest builders, applying a combination of bubbles and plant material to house their eggs after spawning!