The Polypterus Senegalus, sometimes called the Senegal Birchir, Reed Fish, Dinosaur Eel, or Swamp Dragon, is not your garden variety aquarium fish. With their serrated dorsal fins, pronounced teeth, protruding nostrils, and wide, iridescent eyes, it is easy to understand why some people call Polypterus senegalus the Swamp Dragon. Though these fish somewhat resemble eels as well, they are not related. Any common names linking the Polypterus senegalus to eels are misnomers. These fish have characteristics that are truly unique to the Polypterus genus.
General Description of the Polypterus Senegalus
The Polypterus senegalus comes from heavily vegetated, slow moving water systems in Africa and India. They are very common in these areas, so common, that they are often found in roadside ditches. These fish are predators that lay in wait for their prey amongst vegetation in murky waters.
Swamp Dragons grow to be 30 cm long. These fish hunt by smell, and therefore have long, protruding nostrils (much like a dragon) to pick up the scent of their prey. The swamp dragon is covered with thick scales (unlike eels, as eels are scaleless). These scales serve as armor to protect the Swamp Dragon from injury.
The Polypterus senegalus has a modified swim bladder that acts as a primitive lung. This allows the Swamp Dragon to directly breath oxygen, and they will often shoot up to the surface for a gulp of air. These fish, as long as they stay wet, can survive for extended periods of time out of water.
Swamp Dragons are quite hardy and can tolerate a wide variety of water conditions, but this should not be an excuse to forgo regular aquarium maintenance. Water temperatures should be between 25-29ª C for the Polypterus senegalus.
Since the Senegal Birchir reaches a fair size, they should have an aquarium no less than 20 gallons. The Swamp Dragon is one of the few fish that are appropriate for tall and hexagonal fish tanks, because their primitive lung allows them to thrive in oxygen deprived water.
This primitive lung, as mentioned in the previous section, causes the Polypterus senegalus to dart up to the surface of the tank for a gulp of air. As the Swamp Dragon does this, it often shoots right out of the tank, condemned to a slow, painful death, drying out on the floor. For this reason, every gap in the hood of an aquarium meant to house the Swamp Dragon should be covered, as they seem to be able to slip out of the smallest spaces.
Though the Senegal Birchir is a voracious predator, it is an otherwise peaceful fish. Swamp Dragons can be kept in groups. As long as other fish are too big to be seen as prey (at least half the size of the Swamp Dragon) the Polypterus senegalus can coexist peacefully with other species.
The Swamp Dragon is not picky about its prey, and will eat almost anything. Even if a fish is a bit too large to be swallowed, the Polypterus senegalus may try anyway. This is why tank mates have to be at least half the size of the swamp dragon.
Luckily, the Senegal Birchir will eat other foods besides live feed. Pellets that sink to the bottom are readily eaten by the Swamp Dragon, as are freeze dried, frozen, and even flake foods. If Polypterus senegalus is fed primarily prepared diets, the predatory behavior they can exhibit is kept to a minimum, allowing the aquarist to keep smaller fish with the swamp dragon.
The Polypterus senegalus is referred to by a number of different common names, and is often confused with eels. Swamp dragons, though, are truly unique fish, and perfect for the aquarist who wants to add a little mystery to his fish tank.