Saddled Bichir
- Rodrigo
- Mar 17
- 5 min read
The saddled bichir (Polypterus endlicherii) is a member of the family Polypteridae within the order Polypteriformes of the class Actinopterygii. It is a predatory fish commonly seen in the aquarium trade. Because of its highly primitive appearance and body structure that differs markedly from most other bony fishes, it is often called a “dinosaur fish” in the aquarium market. The saddled bichir is characterized by a series of saddle-like markings across its body; in Chinese-speaking markets it is commonly known as the “tiger-pattern dinosaur fish,” while in English it is referred to as the saddled bichir.
Morphology
Morphologically, the saddled bichir possesses the most distinctive feature of the family Polypteridae: a series of separate dorsal finlets along the back. These small, segmented dorsal spines are one of the most important diagnostic traits used to identify bichirs.
In addition, unlike most ray-finned fishes, the saddled bichir retains many characteristics of early actinopterygians. One example is the presence of ganoid scales. These scales consist of several structural layers: a heavily mineralized ganoine surface layer, a dentine-like cosmine layer, a vascular layer containing pulp cavities, and an inner layer of parallel bony plates known as isopedine.
Because its natural habitat consists of densely vegetated swamp environments, the saddled bichir has evolved a cylindrical body and a flattened head that allow it to maneuver through complex benthic terrain. To survive in wetlands and lakes where seasonal droughts occur, these fishes have also convergently evolved spiracles and a specialized swim bladder that functions in aerial respiration. This adaptation allows them to temporarily leave drying pools during the dry season and search for more suitable water bodies.
In terms of coloration, the saddled bichir displays distinctive saddle-shaped markings across the body. These patterns can vary with age, subspecies from different regions, and individual variation. In body size, the species is considered a medium-sized predatory fish, typically reaching about 30–60 cm in length, with maximum sizes reported at approximately 50–65 cm.
During development, members of the family Polypteridae differ from most other fishes in that their juveniles possess external gills, giving them an appearance similar to amphibian larvae. The evolutionary reason for this unusual feature remains unclear. However, it is known that these external gills gradually regress and disappear as the fish matures.
Native Range and Habitat
The saddled bichir is native to West and Central Africa. Its distribution includes the Niger River, the Nile River, Lake Chad, and the Bandama River basin. The species primarily inhabits freshwater rivers and slow-moving waters.
As an ambush predator, the saddled bichir prefers habitats with slow currents, shallow areas, dense vegetation, and muddy or sandy substrates. When dissolved oxygen levels decline, the fish can supplement its oxygen supply through air breathing using its lung-like respiratory system.
Aquarium Conditions
The saddled bichir is a medium-sized predatory fish and is generally recommended to be kept individually. It should not be housed with small fishes or highly aggressive large predators. If mixed housing is desired, suitable companions are typically large, relatively peaceful fish species.
Aquarium size should be based on the adult body length of the fish. A single individual requires at least a 300–500 liter aquarium to allow sufficient space for turning and movement. If multiple individuals are kept together, a significantly larger aquarium is necessary. Bichirs are also powerful jumpers, so aquariums should be equipped with a well-fitted, ventilated lid to prevent escape caused by stress or surface breathing.
In terms of habitat structure, the saddled bichir is a classic ambush predator that prefers dark or sheltered spaces. The aquarium can include driftwood, caves, dense vegetation, or floating plants to create hiding areas. The substrate should consist of sand or fine gravel. Strong direct lighting should be avoided, as it may cause stress.
Water conditions should generally be maintained at temperatures of 24–28°C, with neutral to slightly acidic water chemistry (approximately pH 6.5–7.5). Water flow should be gentle, produced by moderate filtration rather than strong currents.
Because the species is a benthic carnivore, uneaten food and organic waste can accumulate quickly. Regular water changes are therefore necessary, typically around 20–30% per week depending on water quality. A high-quality filtration system combining biological filtration and mechanical filtration is strongly recommended.
Feeding Conditions
The saddled bichir is a bottom-dwelling carnivore. In the wild it feeds primarily on small fish, crustaceans, earthworms, insects, and other aquatic invertebrates. In captivity it can also accept sinking carnivorous pellets as well as frozen foods such as bloodworms, shrimp, or fish meat.
A varied diet is recommended to maintain balanced nutrition. Adult individuals are typically fed once per day or once every other day, depending on activity level and feeding response. Juveniles require more frequent feeding, usually one to two times per day.
Feeding is best conducted in dim lighting or during dusk or nighttime hours, as the species is largely nocturnal and tends to feed more actively under low-light conditions.
Breeding Conditions
Information on reproduction in the wild remains limited. However, records from the aquarium trade indicate that successful artificial breeding has occurred in recent years, particularly in breeding facilities in Indonesia and other parts of Southeast Asia.
Breeding usually requires a dedicated spawning aquarium and a staged management approach, including a spawning environment, egg transfer or incubation tanks, and rearing conditions for larvae. Bichirs typically spawn in environments with fine sand or soft substrates combined with low-growing, fine-leaf aquatic plants such as Java moss.
After spawning, plants carrying fertilized eggs are often transferred to a separate incubation tank maintained at approximately 27–28°C with a pH of about 6.5–7 to increase hatching success. Adult fish may consume eggs or larvae, so separation between adults and eggs is necessary, along with plant structures or incubation systems that protect developing embryos.
Preventing Invasive Spread
The saddled bichir is native to Africa and is a highly adaptable carnivorous fish. When released into non-native environments, abandoned individuals can become invasive species that threaten local ecosystems.
They may prey on the eggs and juveniles of native fish species and compete for food resources, potentially disrupting native fish populations. For this reason, aquarium keepers must follow the principle of responsible ownership and never release captive fish into natural waterways.
If a keeper can no longer maintain the fish, the animal should be transferred to another aquarist or, if possible, rehomed through an aquarium facility willing to accept it. Under no circumstances should the fish be released into the wild.
Author: Rodrigo
References:
Froese, R., & Pauly, D. (Eds.). Polypterus endlicherii summary. FishBase.
SeriouslyFish. (n.d.). Polypterus endlicheri endlicheri (Saddled Bichir) — species profile.
Polypterus.info. (n.d.). Keeping Polypterus — husbandry and diet notes.
AquariumSource. (n.d.). Bichir Care 101.
Taiwan Fisheries / TFRI & MOA species pages
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