An ancient, prehistoric-looking 'upper-jaw' bichir native to the Congo River basin. They are fascinating bottom-dwelling predators with paired lungs, requiring access to the water's surface to breathe atmospheric air. While generally peaceful towards tank mates too large to swallow, they are highly opportunistic nocturnal predators. A tight-fitting lid is mandatory, and fine sand substrate is critical to prevent fatal impaction during their lunging feeding behavior.
Marbled Bichir At a Glance
Marbled Bichir Tank Requirements
Will Marbled Bichir fit in your tank?
Care guides tell you what Marbled Bichir needs, the next question is whether your tank can safely provide it. Test Marbled Bichir against your tank size, maintenance needs, and the fish you already keep before you buy.
Marbled Bichir Water Parameters
Marbled Bichir Temperament & Compatibility
Marbled Bichir Varieties
Each variety inherits the species defaults above. Only differences are highlighted.
Adult / Standard
The fully grown adult form. Requires a large footprint tank with robust filtration. Any tank mates must be tall-bodied or exceed 10-12cm (4-5 inches) to avoid becoming prey.
Same care requirements as the base species
Also known as: Adult, Full Grown
Juvenile (Grow-out)
Juveniles are typically sold around 7-10cm (3-4 inches). While they can temporarily be housed in smaller aquariums, they grow rapidly during their first year and will quickly require a permanent large-footprint tank.
Differs in 5 traits from base species
Also known as: Baby, Small
Marbled Bichir Care Guide Summary
The Marbled Bichir, scientifically known as Polypterus polli, belongs to the Oddballs family group. Adults reach a maximum size of approximately 32 cm and have a eel body shape with a moderate growth rate. Classified as semi-aggressive, this species primarily occupies the bottom zone of the aquarium and produces a high level of biological waste.
To thrive, the Marbled Bichir requires a freshwater only aquarium with a minimum volume of 285 litres and a tank length of at least 120 cm. Water temperature should be maintained between 24°C and 28°C, with a pH range of 6.5–8 and a general hardness of 5–15 dGH. A low water flow is preferred.
Due to its specialist needs, the Marbled Bichir is best suited for fishkeepers who can provide a carefully planned setup. This species is available in 2 varieties: Adult / Standard and Juvenile (Grow-out). Each may differ slightly in size, temperament, or care needs, so it is worth checking the specific requirements of the variety you plan to keep.
Marbled Bichir Habitat Setup
When setting up an aquarium for the Marbled Bichir, a low water flow best suits their natural preferences. Because this species occupies the bottom zone, the aquarium layout should prioritise sufficient floor space with hiding spots among rocks, wood, or dense planting. Useful additions include a sand substrate to accommodate their sifting behaviour, smooth gravel or rounded substrate to protect their sensitive barbels, and driftwood, which can serve as both a hiding place and a dietary supplement. Keepers should note that a tight-fitting lid is essential, as this species is a known jumper.
Marbled Bichir Compatibility Notes
Classified as semi-aggressive, the Marbled Bichir is adaptable and can be kept singly or in a small group, offering flexibility when planning a community tank. When choosing tankmates, any fish small enough to fit in its mouth will likely be eaten and ornamental shrimp are not safe companions. Selecting tankmates that favour different water layers from the bottom zone can help reduce competition and territorial overlap.
Who Marbled Bichir Is Actually For
Marbled Bichir is best for a fishkeeper who wants a species that can settle into a calmer community setup and can provide someone who understands its individual space requirements. It makes the most sense for a hobbyist who will actually build around its needs, especially sand.
The most common mistake is treating Marbled Bichir like any other community fish and skipping the soft sand it needs to forage safely. Another frequent problem is forcing it into an over-busy community when it would do better with more room or more deliberate tankmate choices.
Marbled Bichir Recommended Tank Sizes
Standard aquarium sizes that meet the minimum volume and length requirements for Marbled Bichir.
90 Gallon Standard
125 Gallon Standard
150 Gallon High
180 Gallon Standard
350 Liter (120cm Deep)
450 Liter (150cm Standard)
Marbled Bichir Feeding & Diet Considerations
The Marbled Bichir is a predatory species that will readily consume small fish, so nano or bite-sized tankmates should be avoided, will hunt and eat ornamental shrimp, making it unsuitable for shrimp-focused setups, and is primarily active at dusk and dawn, so offering food shortly after lights-off ensures it receives adequate nutrition.
Frequently Asked Questions About Marbled Bichir
How big does Marbled Bichir get?
Marbled Bichir (Polypterus polli) typically reaches a maximum adult size of approximately 32 cm. They have a eel body shape and a moderate growth rate.
What tank size does Marbled Bichir need?
A minimum aquarium volume of 285 litres and a tank length of at least 120 cm are recommended for Marbled Bichir. This ensures enough swimming space and helps maintain stable water conditions.
What water parameters does Marbled Bichir need?
Marbled Bichir thrives in freshwater only conditions with a temperature range of 24–28°C, a pH between 6.5 and 8, and a general hardness of 5–15 dGH. A low water flow is preferred.
Is Marbled Bichir peaceful or aggressive?
Marbled Bichir is classified as semi-aggressive with an aggression score of 6 out of 10. They can work in community setups but may clash with certain tankmates.
Can Marbled Bichir live alone?
Yes, Marbled Bichir can be kept singly or in a group. They are flexible and adapt well to both setups.
Is Marbled Bichir safe with shrimp?
No. Marbled Bichir is known to eat ornamental shrimp and is not recommended for shrimp tanks. Even larger shrimp species like Amano Shrimp may be at risk.
Does Marbled Bichir have any special tank requirements?
Yes. Marbled Bichir benefits from sand (sifters), driftwood (digestion/hiding), and smooth gravel (sensitive barbels) in the aquarium. These features help replicate their natural habitat and promote overall health and well-being.
Does Marbled Bichir need a lid on the tank?
Yes. Marbled Bichir is a known jumper, and a tight-fitting lid or cover is essential to prevent escape. Even a small gap can be enough for a determined fish to leap out.
Useful setup supplies
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Guidarium Editorial Desk
Reviewed against Guidarium care, stocking, and compatibility standards. Read the editorial policy.
- Last reviewed
- May 6, 2026
- Last updated
- May 6, 2026
- Issues or corrections?
- Contact the editorial team
Plants That Suit Marbled Bichir
These plants pair well with Marbled Bichir based on shared water preferences, layout fit, and how likely they are to hold up in the same aquarium.
Amazon Frogbit
Limnobium laevigatum
Asian Watergrass
Hygroryza aristata
Asian Watermoss
Salvinia cucullata
Banana Plant
Nymphoides aquatica
Beckett's Water Trumpet
Cryptocoryne beckettii
Broad-leaved Crypt
Cryptocoryne pontederiifolia
Fish Similar to Marbled Bichir
Congo Bichir
Polypterus endlicheri congicus
The Congo Bichir is a prehistoric-looking, bottom-dwelling monster fish and one of the largest species in the Polypteridae family. They are obligate air-breathers and ambush predators that will eagerly consume any tankmate small enough to fit in their surprisingly large mouths. Due to their massive adult size, they require extremely large custom aquariums, heavy filtration, and a tight-fitting lid to prevent escapes.
Saddled Bichir
Polypterus endlicheri
A massive, prehistoric-looking predatory fish native to Africa. Known for its prominent dorsal finlets, striking 'saddled' striping, and ability to breathe atmospheric air using a modified swim bladder. They are bottom-dwelling ambush predators. They are completely peaceful to fish too large to swallow, but highly predatory toward anything else. They must be kept on soft sand, as they swallow their prey whole and ingested gravel can be fatal.
Palmas Bichir
Polypterus palmas palmas
An ancient, primitive bottom-dweller from West Africa known for its dinosaur-like appearance and ability to breathe atmospheric air using modified lungs. While it is one of the smaller 'upper jaw' Bichir species, it is a highly capable ambush predator. It is generally peaceful towards fish too large to swallow, but completely unsafe for small community fish. A tight-fitting lid is absolutely mandatory to prevent escaping.
Weeksi Bichir
Polypterus weeksii
A prehistoric, heavily-armored predatory fish from the Congo River basin. Known for its distinctively large head, thick body, and prominent dorsal finlets. They possess functional lungs and must breathe atmospheric air. While peaceful toward fish too large to swallow, they are highly predatory and will consume anything that fits in their spacious mouths. They are notorious escape artists.
Delhezi Bichir (Armored Bichir)
Polypterus delhezi
An ancient, air-breathing predatory fish from the Congo River basin. Known for its distinct black vertical bands and dinosaur-like dorsal finlets. They are bottom-dwelling ambush predators with poor eyesight but an excellent sense of smell. While generally peaceful with similarly sized or larger fish, they are opportunistic piscivores and will eat anything that fits into their surprisingly large mouths.
Polypterus Bichir Lapradei
Polypterus bichir lapradei
The Lapradei Bichir is a massive, ancient, air-breathing predatory fish native to West Africa. Featuring distinct dorsal finlets and a heavily armored, snake-like body, it is a fascinating 'monster fish'. As nocturnal ambush predators, they will consume any tank mate that fits in their surprisingly large mouths. However, they are remarkably peaceful with robust companions that are too large to eat. A tight-fitting lid is absolutely mandatory as they are notorious escape artists.