Saddled bichir

What it is

This species belongs to the family Polypteridae, which includes some of the oldest living ray-finned fishes. Adults reach lengths between 61 and 76 centimetres, with females typically growing larger than males. The body is long and slender, covered in smooth ganoid scales that form a protective armour. A distinctive feature is the series of 11 to 14 separate dorsal finlets running along the back, rather than a single continuous fin. The colour is usually tannish yellow with four to six vertical black bands on the upper side. These markings can become splotchy towards the belly. The head is flat, and the lower jaw projects slightly beyond the upper jaw. Large fan-like pectoral fins allow the fish to push itself along the bottom or even move short distances on land.

Where it lives

The saddled bichir inhabits central and western Africa. Its range covers countries such as Benin, Cameroon, Nigeria, and Sudan. In central Africa, it lives in the White Nile system, including the Bahr al-Ghazal and Bahr al-Jabal tributaries. Western populations are found in the Niger, Comoé, Bandama, Volta, and Ouémé Rivers, as well as the Chad Basin. The species thrives in slow-moving waters rich in vegetation or other cover. It also tolerates brackish environments. While its range overlaps with other bichirs like the grey bichir, it often occupies deeper waters compared to those species.

How it lives

Adults are primarily nocturnal hunters that rely heavily on their sense of smell. They feed on fish such as tilapia and catfish, as well as crustaceans, mollusks, and scavenged carcasses. Younger fish face predation from crocodiles, fish-eating birds, and large predatory fish like the Nile perch. Despite being ambush predators, they are opportunistic feeders. The species has a unique respiratory system derived from a modified swim bladder that functions as a lung. This allows them to gulp atmospheric air, enabling survival in oxygen-depleted or stagnant waters. They can also remain out of water for short periods thanks to this adaptation.

Breeding and life cycle

Spawning occurs during the rainy season, triggered by changes in water temperature and chemistry. Males signal readiness by cupping their enlarged anal fin. They follow females, nudging them with their bodies and cupped fins. Courtship may involve breaching behaviour. When ready, the female releases eggs while the male fertilizes them using his milt. Eggs are scattered among vegetation. Fry hatch after approximately three days, measuring about five millimetres in length. Larvae initially possess external gills, which are shed once internal lungs develop fully. Some captive specimens retain external gills into the juvenile stage.

Fish and people

The saddled bichir is highly sought after by aquarium hobbyists due to its prehistoric appearance. Most traded individuals are wild-caught, which poses a threat to natural populations. Released pets have established small invasive populations in places like Florida. Locally, the fish is harvested for food in central and western Africa, though it is not widely traded for consumption outside its native range. Despite its regional significance to Nile-dependent communities today, there is no evidence that ancient Egyptians depicted this species in art or culture.

Status and threats

The International Union for Conservation of Nature listed the species as Least Concern in 2019. This status reflects its widespread distribution across Africa. No specific population estimates have been made. The primary threat comes from the exotic pet trade, where wild collection is extensive. Habitat degradation and competition with other bichir species are not currently cited as major threats. The species' ability to survive in varied and oxygen-poor environments contributes to its resilience.

Relatives and look-alikes

The saddled bichir shares its family with the genus Erpetoichthys and the other Polypterus species. It is closely related to the grey bichir and the Nile bichir. These species often inhabit overlapping ranges but avoid direct competition by occupying different ecological niches. For example, the grey bichir prefers shallower waters near banks, while the saddled bichir tends to stay in deeper areas. Genetic sequencing places bichirs in the subclass Cladistia, highlighting their early divergence from modern teleosts.

Questions people ask about Saddled bichir

Good reading and sources

• Early members of ‘living fossil’ lineage imply later origin of modern ray-finned fishesNature, Article

• Polypterus endlicherii on WikipediaEncyclopedia
• More photos on Wikimedia CommonsPhotos
• Wikidata recordOpen data