Ropefish
(Erpetoichthys calabaricus)

Ropefish or Erpetoichthys calabaricus belong to the family bichir. It is the sole member of the genus Erpetoichthys. The rope fish is endemic to West Africa. Their natural habitat stretches from Nigeria to the Congo.

Their biological classification is a source of amusement. In Greek erpeton means creepy thing while ichthys means fish. Put it together and you have one creepy fish. These eel-like creatures are commonly referred to as reedfish or snakefish throughout the world. In the U.S. they are marketed under the name ropefish.

The creepy thing fish evolved in low oxygenated habitats. Not only is it capable of breathing oxygen. It can survive without any water at all for intermediate periods of time. Unlike many bi-breathers they are not a member of the suborder Anabantoidei. This suborder covers an array of bi-oxygen breathers such as betta fish and gouramis who use a lung-like organ known as a labyrinth to consume atmospheric oxygen. Ropefish do not have a labyrinth. They consume atmospheric oxygen in a manner unique to their species.

The ropefish takes in airborne oxygen through its gills. Air travels down their esophagus and into their swim bladder. Their modified swim balder absorbs the oxygen from the air and introduces it into the bloodstream.

Ropefish possess other unique traits. They lack ventral fins but have multiple dorsal fins on their back. They also have two sensory organs that extend from their nostrils. These are used to sniff out their food.
The ropefish is a large species. In the wild they will grow up to 36 inches long. It is common for them to reach a length in excess of 16 inches in aquariums. If you intend to keep one you will need a large aquarium.

Despite their creepy appearance and size they are not at all an aggressive creature. They are, in fact, quite docile. The ropefish is timid enough to be harassed by more aggressive species, even fish much smaller than it is. They will, however, swallow their smaller tank-mates whole when feeding time roll around. They will fend for themselves just fine in a very large community aquarium devoid of predators and bullies.

The ropefish is a primarily nocturnal species. You need to provide nocturnal species with caves or hollow aquarium décor to rest in during the day. They also feel more at home in a heavily planted environment. You will want to house them in a well sealed aquarium. Because of their ability to survive out of water, they have a tendency to venture outside of their aquariums.

Ropefish thrive in slightly acidic, medium-hard water. Acceptable temperature ranges are72-82 °F.

Ropefish are carnivorous. They are not known to breed in captivity. You will be purchasing a species that has recently been removed from its native environment. In their natural habitat they survive on worms, crustaceans, insects and smaller fish. They are accustomed to dining on live food and may demonstrate a reluctance to eat anything else when they are first introduced to an aquarium. They will readily devour tubifex and bloodworms. Given time they may learn to tolerate frozen and freeze-dried food.