Setting up the Perfect Bichir Tank: Tank Requirements and Setup Guide

Not every fancier of tank fishes has met bichir fish. Though, those who have will never be able to forget this unique and extraordinary fish, no wonder that its second name is dragon bichir. In this article you will read about care, feeding and how to choose its tank mates. Unfortunately, it is quite complicated to describe each genus of the fish separately, but in general they have almost the same requirements as for care and keeping in a tank. Only the fish size imposes some restrictions. Because some species are unsuitable to keep in a home aquarium due to their large size.

Habitat in the wild

Bichirs or dinosaur bichir (lat. Polypteridae) is a family of freshwater ray-finned fishes, the only one in the order Polypteriformes and subclass Cladistia. Polypteridae includes two genera: Polypterus and Erpetoichthys.

How many types of bichir are there? Nowadays, there are 14 modern genus of the fish known and spread over tropical Africa. Erpetoichthys calabaricus also belongs to this class. Aquarists know it as a reedfish or ropefish.

This is quite an ancient group that has some similar characters with lobe-finned fishes and lungfishes that appeared independently. The earliest fossil remains of polypterids fishes are dated back to the Mesozoic era, which means that the genus has existed for about 60 million years!

Modern Polypterids species occur in freshwater basins in Africa, particularly in the Nile, Congo, and Niger river systems. They can be found in swamps, rivers, and lakes with slow-moving or stagnant water. The fish prefers muddy water and silted bottom, it can even live in bogs. The bichir navigates in water (which is not transparent) due to its sense of smell, at that it has quite poor sight.

Bichirs are adapted to live in slow-moving or stagnant waters with low oxygen levels. Bichirs possess both gills and a modified swim bladder, known as a lung, which enables them to extract oxygen from the air. This adaptation allows them to survive in oxygen-poor or low-water conditions.

They can tolerate a wide range of water parameters, including pH levels that range from slightly acidic to slightly alkaline. The temperature of the water typically falls within the tropical range, between 75 to 82 degrees Fahrenheit (24 to 28 degrees Celsius).

Bichirs are predominantly nocturnal and exhibit a secretive nature. They are generally solitary and territorial, often hiding among vegetation or seeking shelter in crevices during the day. Bichirs are carnivorous and primarily feed on small fish, invertebrates, and occasionally, amphibians. They are opportunistic feeders and can be trained to accept a variety of prepared foods in captivity.

Some Polypterids species are constant tank dwellers. Among them are the following: barred bichir (Polypterus delhezi), ornate bichir (Polypterus ornatipinnis), marbled bichir (Polypterus palmas), and senegal bichir or gray bichir (Polypterus senegalus).


Since an ancient fish is supposed to look ancient, fishes body looks quite archaic. The bichir skeleton resembles that of a shark and it is not made from bones, but from cartilages.

Bichir fish (family Polypteridae) can vary in size depending on the species. Maximum length of Polypterids species body is over 100 cm (39 in), but most of them aren’t longer than 25 cm (9.8 in).

. Here is a general overview of the size range for different bichir species:

  1. Senegal Bichir (Polypterus senegalus): This species is commonly available in the aquarium trade and can reach a maximum size of around 12 to 20 inches (30 to 50 centimeters) in length.
  2. West African bichir or retropinnis bichir (Polypterus retropinnis): Gray bichirs are relatively smaller, typically growing up to about 10 to 14 inches (25 to 35 centimeters) in length.
  3. Ornate Bichir (Polypterus ornatipinnis): Ornate bichirs are larger in size and can reach lengths of about 18 to 24 inches (45 to 60 centimeters) as adults.
  4. Delhezi Bichir (Polypterus delhezi): This species can grow to a size of around 16 to 20 inches (40 to 50 centimeters).
  5. Lapradei Bichir (Polypterus lapradei): Lapradei bichirs are known to be one of the larger species, with individuals reaching lengths of 20 to 30 inches (50 to 75 centimeters) or more.

Bichirs have a relatively long lifespan, with some individuals living for 15 to 20 years or more in captivity when provided with proper care and conditions.

Bichirs have elongated bodies covered in bony scales and have several pairs of lobed fins, which resemble limbs. The body is covered with diamond shaped flexibly joined scales. If Polypterids skin stays wet, it can stay out of water for some time. The skin is very strong and it is kind of armor, that protects the bichir from other carnivorous species.

The dorsal fin consists of a row of 5-18 small fins, which defined the name of Polypterids. Pectoral fins of the bichir evolve from a fleshy blade, which visually resembles lobe-finned fishes construction (however, their skeletons are completely different).

Like paleobiospecies of the fishes found, Polypterids can breathe with atmospheric air. Ray-finned fishes have quite specific air-bladder. It consists from two sections (right one which is large and left one, which is smaller). Both sections are connected with intestinal tract by means of common channel and actually act as an additional respiratory organ (apart from grills).

This allows Polypterids to gasp some air from water surface, which is quite useful when living in water basins with low oxygen content. At that (unlike lungfishes) the bichir doesn’t have choanas.

Difficulties in keeping

Bichirs have been living in tanks since the beginning of the 20-th century. Keeping the bichir in a tank doesn’t seem to be a difficult task: these species are not demanding and are quite enduring, they can live in rather dirty water.

However, this is a predator and only large fishes can be their tank mates. Another thing is, that the bichir is a slow one and it takes a while for it to find the food, which can be a problem when dwelling together with fast fishes in the tank – bichirs may starve.

This fish can be recommended to beginners, if the latter will be capable to provide it with proper tank conditions, since yet it is rather specific and unusual fish.

Keeping in a tank

Tank size

The tank size for bichirs depends on the species and the expected adult size of the bichir you plan to keep. Bichirs are known to grow relatively large and require spacious tanks to accommodate their size and swimming behavior. To keep one you will need a tank of at least 44 gallons (200 litres) capacity and it’s better to be larger. The cover is a must for such a tank! Bichirs can not only jump out of the tank, but also crawl out of it. There should be some air between the cover and tank water surface, otherwise the fish won’t be able to breathe.

Water parameters

Here are proper tank water parameters for bichir keeping:

  1. Temperature: Bichirs are tropical fish, and the water temperature should be kept within a range of 75 to 82 degrees Fahrenheit (24 to 28 degrees Celsius). It is essential to provide a stable temperature, as sudden fluctuations can stress the fish.
  2. pH Level: Bichirs can tolerate a wide range of pH levels. The ideal pH range for most bichir species is between 6.5 and 8.0. It’s important to note that different species may have slight variations in preferred pH, so it’s best to research the specific needs of the species you intend to keep.
  3. Hardness: Bichirs will feel comfortable both in soft and hard water, though it’s better not to take chances with extremely hard water (higher than 20). A general range of 5 to 20 dGH (degrees of General Hardness) is suitable for most bichirs.
  4. Ammonia, Nitrite, and Nitrate: Bichirs are sensitive to ammonia and nitrite, which are toxic substances produced by fish waste and decaying organic matter. Regular monitoring and maintenance are essential to keep these parameters at safe levels. Ideally, ammonia and nitrite levels should be maintained at zero, while nitrate levels should be kept below 20 parts per million (ppm).
  5. Filtration and Water Quality: Bichirs require efficient filtration to maintain good water quality. A properly sized and well-maintained filter should be able to handle the waste produced by the fish and help maintain stable water parameters.
  6. Water Changes: Regular partial water changes are necessary to keep water quality in check and dilute any accumulated toxins or impurities. Aiming for a 20% to 30% water change every 1 to 2 weeks is a good guideline, although the frequency and volume can vary based on the specific needs of your bichirs and the size of the tank.
  7. Aeration: Despite the fact that bichir itself doesn’t need any aeration in the tank, the tank ecosystem will benefit from it.

Tank decor

Tank decorations may be of any kind you like. Stones, caves, castles will do. Live tank plants are desirable, but not necessary.

Since bichirs is mostly a bottom-feeder, the tank bottom substrate should be easy in care and cleaning. It’s better be a thin layer of sand, though small grained gravel will do as well. But the latter is less natural like for the fish and it will be more difficult for the fish to feed from it.

Some aquarists advise to keep bichirs in an empty tank, to decrease their territory dependence. But the view of the fish swimming in a tank without decorations or caves is a bit depressing. On the other hand, the fish looks more fascinating when it is slowly creeping up between tank plants or stones in a good decorated tank.

Smooth stones, snags, caves will perfectly do as tank decorations. You can also use ceramic and plastic tubes, but they look less natural.

Filtration in tank – it’d be excellent to have a powerful canister filter with ability to clean water using both mechanical and biological filtration. Though the bichir is not quite active and it doesn’t leave much litter if compared to other fishes, but protein food is a source of many small leftovers, that make tank water toxic very fast without proper filtration.


Bichirs prefer a soft substrate that allows them to bury themselves partially or completely. Soft substrates such as sand, fine gravel, or a mix of sand and small rounded pebbles are ideal. Avoid using sharp or rough substrates that could potentially harm their delicate skin. Bichirs often dig and bury themselves in the substrate, so providing an adequate substrate depth is essential. Aim for a substrate layer that is at least 2 to 3 inches (5 to 8 centimeters) deep. This depth allows bichirs to exhibit their natural digging behaviors and provides them with a comfortable resting place.


In their natural habitat, bichirs feed on small fish, invertebrates, and occasionally, amphibians. When keeping bichirs in an aquarium, it’s important to provide a varied and nutritious diet that meets their dietary needs.

The majority of a bichir’s diet should consist of meaty foods. Bichirs is a predator fish and you should feed it basically with live food: small fish (guppies) bloodworm, blackworms, frozen shrimps, small fishes, pieces of ox heart and meat, earthworm. Providing a diverse range of meaty options ensures that they receive a balanced diet.

The fish may also feed on artificial food, but this kind of diet is not natural for it. This can include high-quality pellets or sinking carnivore-specific pellets. It’s important to choose pellets that sink quickly, as bichirs are primarily bottom-dwelling fish.

The bichir feature is that it eats slowly, since in the wild the fish goes hunting at night when its prey is not active. So, if you noticed that some tank dwellers disappear at night, this may be the reason.

Bichirs have a unique feeding behavior where they suck in their prey using their tube-like mouth. To stimulate their natural feeding instincts, you can use feeding tongs or tweezers to present the food in front of them. This allows them to actively hunt and capture their prey. When offering meaty foods, it’s essential to consider the size of the bichir’s mouth and the prey items. Ideally, the food should be small enough for them to swallow comfortably without causing any blockages or stress. Adjust the food size as the bichir grows to accommodate their increasing mouth size.

Bichirs are generally opportunistic feeders, and their feeding frequency can vary depending on their size and age. Juvenile bichirs may require daily feedings, while adult bichirs can be fed every other day or even every few days. Monitor their appetite and adjust the feeding schedule accordingly, being mindful not to overfeed.

tank mates

Any fish will do as bichir tank mate, the main thing is that it shoudln’t fit into its mouth. Bichirs have a tendency to eat smaller fish and invertebrates, so it’s crucial to choose tankmates that are compatible with their behavior and size. Bichir never attack large healthy fish without a reason. Sometimes bichir may even attack the fish of larger size, though usually this happens due to the bad eyesight.

Fishes of the same size as fish will do as its tank mates. These can be oscar, blood parrot, green terror and so on. I wouldn’t recommend to keep together with flowerhorn, since the latter may kill even such a protected fish.

Here’s a chart that provides some examples of potential tankmates for bichirs based on their size, temperament, and compatibility:

Bichir SpeciesTankmate Suggestions
Polypterus senegalusLarger catfish species (e.g., Synodontis species), larger tetras (e.g., Buenos Aires tetra), larger barbs (e.g., Tiger barb), larger gouramis (e.g., Pearl gourami)
Polypterus retropinnisLarger catfish species, larger tetras, larger barbs, larger gouramis, larger loaches (e.g., Clown loach), larger danios (e.g., Giant danio)
Polypterus ornatipinnisLarger catfish species, larger tetras, larger barbs, larger gouramis, larger loaches, larger danios, larger cichlids (e.g., Angelfish)
Polypterus delheziLarger catfish species, larger tetras, larger barbs, larger gouramis, larger loaches, larger danios, larger cichlids, larger characins (e.g., Silver dollar fish)
Polypterus lapradeiLarger catfish species, larger tetras, larger barbs, larger gouramis, larger loaches, larger danios, larger cichlids, larger characins

How many bichirs can live together?

The number of bichirs that can live together in a single aquarium depends on several factors, including the tank size, individual sizes, temperament, and sex of the bichirs. Bichirs are generally solitary and can become territorial, especially as they grow older and larger. In some cases, keeping multiple bichirs of the same species together can work well, particularly if they are introduced at a young age and in a spacious environment. However, it’s important to closely monitor their behavior and provide adequate hiding places and territories within the aquarium to minimize aggression.

Gender differences: male vs female

It is difficult to see between the bichir male and female. As for the indirect distinctive features, these are: wider and thicker anal and dorsal fin of the male, while females are usually larger in size. Females may have a rounder and fuller body shape compared to males, particularly during the breeding season when they are carrying eggs. In mature females, a small genital papilla, also known as a breeding tube, can sometimes be visible near the vent area. However, this characteristic may not be apparent until the fish is ready to reproduce. As for the young species – it’s impossible to see males and females between them.


In a home aquarium bichirs breed quite seldom. Breeding bichirs in an aquarium setting can be a complex process, as it requires providing the right conditions and stimulating natural behaviors.

How many types of bichir are there? There are multiple species of bichir, each with its own unique characteristics. While the exact number of bichir species may vary based on taxonomic revisions and discoveries, the following are some of the commonly recognized and popular species of bichir:

Senegal bichir (Polypterus senegallus)

This is one of the most active and less timid Polypterids species. It is native to freshwater habitats in West Africa, specifically the Senegal and Gambia River basins. It actively swims almost all the time, it is curious and persistent. The fish doesn’t show aggression towards its kind and other tank dwellers if the latter are large enough.

They prefer a tank with a minimum capacity of 50 gallons (190 liters) or larger, with a sandy substrate and plenty of vegetation and driftwood. They are generally peaceful towards other tank mates, but caution should be exercised with smaller fish that can fit into their mouth.

The fish is reasonably large – adult Senegal bichirs can grow up to 14-20 inches (35-50 cm) in length in captivity, depending on their environment and diet. Males tend to be slightly larger than females. I must say, that this is the fish you should get when you start getting to know Polypterids species.

Common NameSenegal bichir, gray bichir, Cuvier’s bichir
Scientific NamePolypterus senegalus
Native RegionWest Africa (Senegal and Gambia River basins)
AppearanceLong and slender body with ganoid scales
ColorationLight gray to dark brown with a mottled pattern
Maximum Size14-20 inches (35-50 cm) in length
Fin StructureElongated dorsal fin along most of the body
Respiratory AdaptationPossess lungs in addition to gills
BehaviorNocturnal, solitary, and capable of breathing atmospheric air
DietPiscivorous (fish), crustaceans, and insects
Aquarium CareMinimum tank size of 50 gallons, ample hiding spots
CompatibilityGenerally peaceful, but caution with smaller tank mates
Lifespan10-15 years or more in captivity
Water Parameters– Temperature: 75-82°F (24-28°C)
– pH: 6.0-7.5
– Hardness: Soft to moderately hard

Ornate bichir (Polypterus ornatipinnis)

This is one of the most appealing Polypterids fishes. But unfortunately, it is very timid and you will seldom see it during a day, except when it comes out for food.

Besides the fish is more aggressive towards its kind and may take food from other fishes. It grows to become larger than the previous fish – 60 cm (24 in) in length and therefore it requires more roomy tank. This is a very strong predator fish capable of catching even a fast fish.

Common NameOrnate bichir
Scientific NamePolypterus ornatipinnis
Native RegionCentral Africa (Congo River basin)
AppearanceElongated body with bony plates (ganoid scales)
ColorationDark brown to black with white or yellow spots and markings
Maximum SizeUp to 24 inches (60 cm) in length
Fin StructureElongated dorsal fin running along the back
Respiratory AdaptationPossess lungs in addition to gills
BehaviorNocturnal and primarily solitary
DietCarnivorous, feeding on fish, crustaceans, and insects
Aquarium CareMinimum tank size of 75 gallons or larger, ample hiding spots
CompatibilityGenerally peaceful, but may prey on smaller tank mates
Lifespan10-15 years or more in captivity
Water Parameters– Temperature: 75-82°F (24-28°C)
– pH: 6.0-7.5
– Hardness: Soft to moderately hard

Saddled bichir (Polypterus endlicheri)

Polypterus endlicheri is a large and strong species, that grows to become up to 75 cm in the wild. It is not very active during a day, it mainly slowly swims looking for food. Considering the size, it’s better to keep it in a separate tank and feed with live food (once or twice a week).

Common NameSaddled bichir or Endlicheri bichir
Scientific NamePolypterus endlicheri
Native RegionCentral and West Africa, including the Congo River basin
AppearanceElongated body with ganoid scales
ColorationVariable, ranging from olive to dark brown with saddled markings
Maximum SizeUp to 30 inches (75 cm) in length
Fin StructureElongated dorsal fin and paired pectoral and pelvic fins
Respiratory AdaptationPossess lungs in addition to gills
BehaviorNocturnal, primarily solitary and territorial
DietPiscivorous (fish), crustaceans, and insects
Aquarium CareLarge tank with a minimum capacity of 100 gallons (380 liters)
CompatibilityMay be aggressive towards smaller tank mates
Lifespan15-20 years or more in captivity
Water Parameters– Temperature: 75-82°F (24-28°C)
– pH: 6.5-7.5
– Hardness: Soft to moderately hard

Barred bichir (Polypterus delhezi)

Polypterus delhezi, commonly known as the Armored bichir or Delhezi bichir, is a species of fish belonging to the family Polypteridae. Polypterus delhezi inhabits in Kongo river. It is not very active during a day and it spends its time in shelters. They are ambush predators, patiently waiting for their prey to come within striking distance. They are carnivorous and feed on a variety of prey, including small fish, crustaceans, insects, and other invertebrates. In captivity, they can be fed a diet of meaty foods such as fish fillets, shrimp, earthworms, and occasionally, feeder fish.

Common NameDelhezi bichir
Scientific NamePolypterus delhezi, barred bichir, armoured bichir, bandback bichir, banded bichir
Native RegionCongo River basin in Central Africa
AppearanceElongated body with bony plates (ganoid scales)
ColorationDark brown or black with lighter mottling
Maximum SizeUp to 14-16 inches (35-40 cm) in length
Fin StructureElongated dorsal fin running along most of the body
Respiratory AdaptationPossess lungs in addition to gills
BehaviorNocturnal, solitary, and can breathe atmospheric air
DietPiscivorous (fish), crustaceans, and insects
Aquarium CareMinimum tank size of 50 gallons, plenty of hiding spots
CompatibilityGenerally peaceful, but caution with smaller tank mates
Lifespan10-15 years or more in captivity
Water Parameters– Temperature: 75-82°F (24-28°C)
– pH: 6.0-7.5
– Hardness: Soft to moderately hard

Rope fish (Erpetoichthys calabaricus)

Erpetoichthys calabaricus, commonly known as the Reedfish or Ropefish, is a fish species belonging to the family Polypteridae. Reedfish have a unique and elongated body, resembling a snake. They have a scaleless, cylindrical shape and typically grow to a length of about 12-20 inches (30-50 cm). When keeping Reedfish in an aquarium, it is essential to provide them with a spacious tank. A minimum tank size of 50 gallons or more is recommended to accommodate their size and swimming needs. Ensure that the aquarium has a tight-fitting lid or cover as Reedfish are known to be skilled escape artists.

Common NameReedfish or Ropefish
Scientific NameErpetoichthys calabaricus
Native RegionWest and Central Africa, including Nigeria and Cameroon
AppearanceElongated body with a snake-like appearance
ColorationLight brown to dark gray with dark vertical bands
Maximum SizeCan reach up to 20-30 inches (50-75 cm) in length
Fin StructureLong dorsal fin extending along most of the body
Respiratory AdaptationPossess both gills and a modified swim bladder for breathing
BehaviorNocturnal, peaceful, and curious
DietCarnivorous, feeding on small fish, insects, and worms
Aquarium CareMinimum tank size of 50 gallons, tight-fitting lid
CompatibilityGenerally peaceful, but may eat small tankmates
Lifespan8-15 years or more in captivity
Water Parameters– Temperature: 72-82°F (22-28°C)
– pH: 6.0-7.5
– Hardness: Soft to moderately hard