Bichir, pronounced “be-sheer,” are considered living fossil fish. Also known as “dinosaur eels,” these fish have many unique features. Read on to learn everything you need to know about what makes them so special and discover their types, how to care for them, and more.
What Is a Bichir Fish?
Bichir are a group of bottom-dwelling freshwater fish that are native to northeast and western Africa (i.e., the Nile river basin and its tributaries). They’re a type of ray-finned fish, which began their evolution journey around 395 million years ago.
These prehistoric fish belong to the genus Polypterus, which means “many wings.” Bichir have long, narrow, tubelike bodies covered in thick diamond-shaped scales. These scales are coated in a shimmery enamel-like compound called ganoine (or ganoid). Ganoine-coated scales are seen in some of the earliest ray-finned fish species.
What makes bichir fish unique is that they’ve adapted to living in dry environments by growing modified lungs, similar to lungfish. These lungs can help them survive even if they're out of the water for several hours. They can also live in places with low water levels like bogs, estuaries, and floodplains.
Like most bottom-dwelling fish, bichir fish have poor eyesight. They compensate for this deficiency with a strong sense of smell and powerful sensory organs, which help them survive in their natural habitat.
Bichir fish have a semi aggressive and predatory nature. They can use their pectoral fins to simulate a motion similar to a “walk” at the bottom of water bodies and prey on smaller fish in their surroundings.
What Are Some Bichir Fish Types?
There are several varieties under the Polypterus genus, like the shortfin bichir, mottled bichir, cross-river bichir, and West African, Congo, Nile, and Guinean bichir species. Here are some of the most popular types of bichir fish:
Barred bichir (scientific name Polypterus delhezi). These fish have a grayish body containing green or occasionally yellow spots and appear similar to ornate bichir.
Dinosaur or gray bichir (scientific name Polypterus senegalus). These fish are most commonly spotted in aquariums. They’re also known as swamp dragons, dinosaur eels, and reed fish. Some of the most popular varieties include platinum Senegal bichir (a relatively new find) and albino bichir, which have unique red eyes. They’re the smallest bichir species, growing only up to 14 inches. They’re available in multiple colors like blue, pink, white, and grey. They have large pectoral fins and serrated dorsal fins.
Ornate bichir (scientific name Polypterus ornatipinnis). These fish contain both light and dark colors contrasting on their bodies, which makes them appear very attractive. For example, they may have bright yellow patterns on a dark brown body, giving them a decorative appearance. They grow to a length of around 24 inches.
Saddled bichir (scientific name is Polypterus endlicheri). This is the largest bichir species and grows up to a length of 30 inches. Saddled bichir are considered very beautiful fish because of their unique coloring and appearance. They have white bodies with dark-colored vertical bands, along with lower jaws that are longer than the upper jaws.
What Is the Bichir Fish Size and Appearance Like?
Bichir fish can grow up to 15 to 30 inches (or 38 to 76 centimeters) in length, depending on the variant, and females are usually a little bigger than males.
Bichir fish have an eel-like body with modified lungs, thick, bonelike scales, and a fleshy pectoral fin, which is shaped like a paddle. Their diamond-shaped ganoid scales have a protective function.
They also have a row of 8 to 15 small, spiny dorsal fins. Each dorsal fin has double-edged bifid tips. These are the only fins with spines, and the remaining fins have a soft raylike appearance.
Bichir have well-developed slit-like nostrils called spiracles at the top of their heads to breathe air and to compensate for their poor vision. They have tetrapod-like jaws, two gular plates, and four pairs of gill arches. They also have a pair of lungs, with the left lung being shorter than the right lung. These are useful for breathing when they’re on the surface or if the water has very low oxygen content.
Bichir fish colors also vary across species. But the most common bichir colors include white, grey, and yellow, with various patterns on their fins and bodies.
How to Prepare a Bichir Fish Tank
As most of the varieties in this species are quite large in size, they require a huge tank of at least 90-gallon capacity. These fish are energetic and need considerable space to swim.
If you’re planning to keep a bichir fish, make sure that your tank has a well-fastened lid, as these fish can crawl up the walls of the tank and jump out. The lid must also have holes to allow air entry so that they can breathe when on the surface.
Bichir fish tanks must contain sand at the bottom because these bottom-dweller fish can use their fins to walk. A sand coating will also protect their bellies from being damaged by any sharp edges. Don’t use gravel, as the fish may accidentally eat it while feeding.
You can also add dim lighting with floating aquatic plants and any decorative items of your choice like stones or shells. A standard filter is sufficient for cleanup of leftover foods and debris, as these fish can survive well even in water with low oxygen content.
Use soft water in the tank at a temperature of approximately 72°F to 82°F (or 22°C to 27°C) and neutral pH of 6.5 to 7.5. Change around 10% of the water weekly, but don’t use any chemical cleaning agents.
How to Care for Bichir Fish
Bichir fish can live up to 20 years in nature and up to 15 to 18 years in an aquarium with proper nutrition, care, and maintenance. Their diet mainly comprises live foods like smaller fishes, crustaceans, worms, and insects.
Clean the tank regularly to protect the fish from parasites and other diseases. You can keep multiple bichir fish together or pair them with other large fish species that won’t compete for their food.
Admire these fish from afar because they can bite, and keep in mind that caring for bichir is an extended commitment due to their relatively long lifespan.
