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Can a Bichir Live in a 20-Gallon Tank?

A bichir (or dinosaur eel, as it’s sometimes called) is a species of primitive freshwater fish that’s believed to have been around since the Mesozoic – almost 60 million years ago! If you’re interested in keeping this peculiar-looking fish as a pet, you may be curious as to what size aquarium it needs? Can it live in a 20-gallon tank, for example? And the answer is…

A single or pair of Senegal or grey bichirs can live (temporarily) in a 20-gallon tank since they’re among the smallest of their kind. For the first 6 months of life, they’ll be fine in this sized tank but after that, they must be moved to a much larger aquarium (75-gallon minimum) as they have the potential to reach adult lengths of 12 inches or more.

Now that you know you can keep a juvenile bichir in a 20-gallon tank, let’s explore this topic further. In this article, we’ll learn what size aquarium is best for this species, what they require in their tank, and how to properly car for them in captivity. I’ll touch briefly on possible tankmates as well ways to keep their aggression to a minimum.

So, if you’re ready to ‘dive deeper’ into the aquatic world of the intriguing and illusive bichir fish, then let’s begin!

How Long Can a Bichir Live in a 20-Gallon Tank?

You can keep a pair of Senegal bichirs in a 20-gallon tank as a juvenile. Once they reach 6 months of age or a combined length of 20 inches, you’ll need to rehome them to a bigger aquarium – at least twice the size or more. This fish is highly active and can reach adult lengths of 14 to 22 inches. Therefore, it needs a very large aquatic environment, not only to survive but to thrive.

Can You Keep a Dinosaur Bichir in a 55-gallon Tank?

Dinosaur bichirs (also known as Senegal or grey bichirs) are fairly large, active fish that like to freely swim and explore their aquatic environment. For this reason, a 55-gallon tank is ok for a few juveniles, but not suitable for adults. It’s simply not big enough to allow them the space they need to keep them content and peaceful in captivity.

dinosaur bichir

Can You Keep an Ornate Bichir in a 55-Gallon Tank?

Ornate or yellow bichirs can grow to lengths of up to 24 inches. For this reason alone, they can’t be kept in a 55-gallon tank for very long. For a fish this size, a 90-gallon aquarium at the very least is required. This species likes to move about – especially at night – and will spend most of its time foraging and exploring its aquatic habitat.

Can You Keep a Saddled Bichir in a 55-Gallon Tank?

Saddled bichirs are one of the largest of their species – reaching adult length of close to 30 inches. This is huge by aquarium fish and as such, an extra-large tank is necessary. A 55-gallon aquarium is much too small for this massive creature. In fact, anything under 120-gallons simply won’t do. When confined to a limited aquatic space, saddled bichirs will become hostile towards other tankmates.

What Size Tank is Best for a Bichir?

A single full-grown bichir needs a 75-gallon tank (minimum) to call home, depending on how large it is. Bigger is always better when it comes to this species, however. Keep in mind the general rule-of-thumb for stocking aquariums which is one inch of fish per every gallon of water. In my opinion, anything less than a 90-gallon tank is not big enough, especially if you intend to keep more than one.

What is the Biggest Fish You Can Put in a 20-Gallon Tank?

Using the rule-of-thumb for stocking aquariums, the largest fish you can keep in a 20-gallon tank is 20 inches in length. By this calculation, you can have one adult bichir or two juveniles. Anything more than 20 total inches of fish must be rehomed to a larger tank.

Are Bichirs Aggressive?

Bichirs can become aggressive or territorial, especially towards other bichirs of equal or lesser size. If confined to a small tank, they can become hostile should they feel the need to compete for food. When fed adequately and kept in a large aquatic environment, this species is usually peaceful in nature.

Can Bichirs be Kept Together?

Bichirs are highly social creatures and as such, like to be kept with others of their kind. A pair or more will often form what’s referred to as a ‘poly pile’ whereby they’ll group together along the substrate in an aquarium.

Do Bichirs Jump?

Bichirs can jump which is why they must be kept in a tank with a tightly fitted lid or cover slide. A 12-inch bichir, for example, can leap as high as 2 feet which makes it the ultimate aquarium ‘escape artist.’ For this reason, you’ll need to plug any holes around pipe inlets and cables as well.

How Long Can a Bichir Live Out of Water?

Should your bichir jump out of its tank, it has the potential to survive for quite some time out of water. In fact, this species can drown if denied access to atmospheric oxygen for too long. Therefore, low water habitats are preferred by this type of fish.

What Kind of Water Conditions do Bichirs Prefer?

Shallow, brackish water conditions are ideal for bichirs. Naturally, they’re found in muddy estuaries with silted substrates – mainly along the Nile River systems in Africa. When in captivity, they require an aquatic environment with a temperature ranging between 72- and 82-degrees Fahrenheit. They also prefer softer water with a neutral pH (6.5 to 7.5).

albino bichir

What do Bichirs Prefer in Their Tank?

The recommended tank size for an adult bichir fish is 90-gallons. Since they grow to be quite large and tend to be active in nature, Senegal bichirs need as big of an aquatic environment as you can provide. Ample room to swim about and explore their surroundings is vital to their health and longevity.

As bottom feeders, they need a soft, sandy substrate. Rocky or gravel-type substrate may lead to injury. Being nocturnal, they also need a blue light to be able to see and forage at night as well as some plants to provide cover sunshine cover during the daytime.

What do I Feed a Bichir?

Bichirs are nocturnal, predatory creatures that prefer live foods such as small invertebrates, crustaceans, and insects. Being carnivores, they’ll also eat tiny fish that happen to swim too close to the substrate. Meaty choices like brine shrimp and bloodworms are better options than pellet foods.

Do Bichirs Eat Plants?

Bichirs are carnivorous and will eat just about anything that can easily fit into their mouths. They won’t eat plants, so feel free to add a few to their tank. In fact, plants are recommended. Not only do they provide coverage from daytime light, but they also help keep the aquarium water clean and oxygenated.

What Fish Make the Best Tankmates for Bichirs?

Larger, peaceful fish makes the best tankmates for bichirs. Fish that prefer to swim near the surface or along the middle of aquarium are perfect, as they’ll stay out of the way of the mainly bottom-dwelling bichir. Some possible examples include Oscars, barbs, and catfish, depending on the size of the tank and the water conditions required.


In summation, a Senegal bichir will be okay in a 20-gallon tank as a youngster or juvenile – about first 6 months of life. As an adult however, it’ll require a more substantial aquarium (at least twice as big or greater) to call home. The size will depend on how many you keep and how large they grow. That said, you really shouldn’t keep more than a pair of bichirs in the same tank at any given time.

I trust this article has been of help in determining whether (or not) you can keep a bichir in a 20-gallon tank. Thanks for reading and best of luck with your aquarium hobby.

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