Bichir (genus Polypterus)

FishFreshwaterLiving fossil

Overview

Bichirs (genus Polypterus) are ancient, elongated freshwater fish of Africa, instantly known by the row of separate little fins — the finlets — running along the back, and by their thick coat of hard, glossy, diamond-shaped scales. Together with the related reedfish, they form an old lineage that branched off near the base of the ray-finned fishes, making them living relics with a host of primitive features. The ornate bichir (Polypterus ornatipinnis) shown here is a popular and striking example.

Most remarkably, bichirs have a pair of true, lung-like organs and must come to the surface to gulp air — they can even survive out of water for a time if kept damp, making them some of the most air-dependent of all fishes.

Note: “bichir” covers several Polypterus species; details here describe the genus broadly. Treat general statements as approximate and verify against authoritative sources.

Habitat & Range

Bichirs live in fresh waters across tropical Africa — rivers, swamps, floodplains, lakes, and shallow, weedy, often slow or stagnant water, including the Nile and Congo systems and many wetlands. Their air-breathing lets them thrive in warm, oxygen-poor water and shallow swamps where many other fish struggle.

Diet

Bichirs are carnivorous predators that hunt mostly at night, eating insects, worms, crustaceans, smaller fish, amphibians, and other small animals. They are slow, deliberate hunters that rely heavily on a keen sense of smell to track prey in murky water, then lunge to engulf it. Their sturdy jaws handle a wide range of prey sizes.

Behavior

The bichir's standout feature is its paired, lung-like air-breathing organs: unusually, it exhales spent air through openings near the gills and then recoils its stiff, armoured body to draw a fresh gulp in at the surface, a distinctive way of breathing air. This lets bichirs live in low-oxygen water and survive brief spells out of water. They are mostly nocturnal and bottom-oriented, often resting among vegetation or cover by day. Their thick scales give protection, and the larvae even have external, frilly gills (a little like a salamander's) before maturing — another of the group's ancient traits.

Human Interaction & Conservation

Bichirs are caught for food in parts of Africa and are popular in the aquarium hobby, where their prehistoric looks and hardy, air-breathing nature make them favourites (responsible keeping and never releasing non-native fish are important). In the wild they remain reasonably widespread across African fresh waters, though habitat loss and water changes can affect local populations. Consult authoritative sources for status.

More photos of the bichir