Bichir

Quick Take

• Bichirs possess a biological trait that almost no other fish on Earth shares, and this trait fundamentally changes how they survive when conditions turn against them. Air-breathing ability →
• At least one bichir species uses its fins in a way that blurs the line between fish and land animal, and this behavior is not just a quirk but a survival strategy. Walking on land →
• Bichirs live dramatically longer under one set of conditions than another, and the reason reveals a surprising vulnerability in an otherwise armored predator. Lifespan in captivity →
• These fish coexist peacefully with most tankmates, but there is one very specific type they cannot tolerate, and the reason why is more territorial than you'd expect from a prehistoric bottom-dweller.

Bichirs are slender, prehistoric-looking fish that are often thought to resemble dinosaurs or eastern dragons. Bichir fish are native to Africa and can be found in nearly every freshwater body on the continent. Their distinctive appearances and highly interactive personalities have also made bichirs incredibly popular as aquarium pets.

3 Incredible Bichir Facts

• Taking a breath: Unlike other types of fish, bichir fish actually have lungs and are capable of breathing both in and out of the water. In fact, many will swim to the surface for a breath when the water is too muddy for their tastes.
• Nocturnal habits: These are predatory fish that come out at night. They like to eat bugs, worms, and other creatures that emerge from the mud when the sun goes down.
• Walking on land: The Senegal bichir fish is known for being able to use its fins to propel itself across the land for short distances. This lets the fish move between nearby ponds or catch prey that is trying to escape from the water.

Classification and Scientific Name

These fish are classified in the genus Polypterus, which means “many-winged.” This refers to the series of delicate fins that line the backs of all of them. They are further classified in the Polypteridae family, which belongs to the Actinopterygii class of ray-finned fishes. There is still a significant amount of debate as to how many different types exist and how they should be classified; at the moment, there are 13 recognized species.

Species

These fish are found in rivers and lakes across the continent of Africa. There are currently 13 different species that are recognized by the scientific community, and many of these species have their own subspecies.

Some of the most popular types include:

• Ornate bichir: Polypterus ornatipinnis are known for their distinctive black and yellow patterns. Although they’re slightly aggressive towards other fish, their appearance makes ornate bichirs incredibly popular as aquarium pets.
• Senegal bichir: Also known as the dinosaur bichir, Polypterus senegalus is one of the most widespread types in Africa. They have large pectoral fins that they use to propel themselves across short stretches of land.
• Saddled bichir: Polypterus endlicheri endlicheri is a pale-colored bichir that occasionally appears with a striking striped pattern. Saddled bichirs are the largest subspecies and can get up to 30 inches long.

Appearance

These are long, slender fish that are often mistaken for eels. Instead of dorsal fins, they have a set of delicate ray fins that grow along their spines. They propel themselves with their pectoral fins, but they also have back fins and prominent tail fins. They come in a wide variety of colors and patterns that change based on their natural habitats. Dinosaur bichirs are a dark grey color, but ornate bichirs come in striking shades of black and yellow.

These fish are often categorized by whether their upper or lower jaw protrudes. While it’s true that lower jaw bichirs often have a strong underbite, upper jaw bichirs typically have smooth jawlines that make the protrusion difficult to notice. Lower jaw bichirs are almost always larger than upper jaw bichirs.

Most of them grow to be 11 to 20 inches long, and they can weigh anywhere from 5 to 10 pounds. Saddled bichirs are one of the longest subspecies; the largest recorded fish was 30 inches long.

Distribution, Population, and Habitat

These fish are native to Africa and can be found in nearly every shallow freshwater river and pond on the continent. Each body of water usually only contains one species of bichir; even in aquariums, they tend to attack bichirs of different species. Dinosaur bichirs can be found all over, but ornate bichirs are limited to the eastern parts of the continent. These fish are incredibly common, and several species are listed as Least Concern on the IUCN Red List, though not all species have been evaluated.

Although they can live in any body of fresh water, the fish prefer muddy, silty environments. These fish are nocturnal, which means they spend most of the day sleeping at the bottom of the river. At night, they hunt for bugs, vertebrates, and other small creatures that inhabit the muddy shallows.

Predators and Prey

These fish are predatory creatures that will eat any animal smaller than them. Their natural prey includes shellfish, vertebrates, bugs, worms, and other fish that are small enough to fit into a bichir’s mouth.

When they are not hunting, they are relatively peaceful fish. They may show aggressive behavior if other predatory fish enter their territory, but they will generally leave large fish alone. These fish have few natural predators due to their size and armor, but they may occasionally be caught and eaten by larger carnivores.

Reproduction and Lifespan

These are egg-laying fish that tend to breed once a year unless breeding is artificially induced. They typically go through one- to two-day courting rituals in which the male chooses and attempts to woo a female. Once the couple has paired off, the female will release up to 300 eggs over a week-long period. The male fertilizes the eggs as they are released and then allows them to be scattered along the riverbed or across the aquarium floor.

The eggs only take 3 to 4 days to hatch. The fry are only 2 to 3 millimeters long, but they grow incredibly quickly. Some species can grow an inch per month. These fish in aquariums tend to live to be 15 to 20 years old; in the wild, their average lifespan is closer to 10 years.

Fishing and Cooking

These fish are kept as aquarium pets and are not traditionally used for cooking. Most sold in pet stores are bred and raised in tanks. Wild bichirs are not fished out of their habitats in quantities large enough to be recorded.