Ropefish

  Ropefish (Erpetoichthys calabaricus) are interesting eel-shaped fish from Africa. They belong to the family Polypteridae.Ropefish are also commonly called "reedfish" or "snakefish" due to their eel-shaped or snake-like body shape.

  If you decide to house one (or several) in your aquarium you will need a  spacious one. Ropefish (or reedfish, whichever you prefer) grow quite  large - up to 16 inches (40 cm) in length so don't plan on keeping them in a small tank.Their tank should be heavily planted with lots of rockwork and caves.  Ropefish need lots of hiding places. They like to move and hide among  the plants and rockwork.  They are mostly nocturnal fish, but will sometimes come out into the  open during the daytime.

  You may keep several ropefish together in the same aquarium and they can even be kept in a community tank. Despite their appearance they are peaceful fish. However, ropefish will eat small tankmates that are easy to swallow. Also don't keep ropefish with aggressive fish that will harass them.

 You should keep their tank covered so they don't escape from the aquarium. Their body shape makes them quite agile and they are able to escape from their tank easily - even through small holes. Another interesting fact about ropefish is that in addition to utilizing  oxygen from the water through their gills, they also utilize atmospheric oxygen. They do  this by swallowing air at the water surface. The air enters their esophagus, which is connected to their swim bladder. Once the air  reaches the swim bladder the oxygen is absorbed into their blood stream. This modified swim  bladder evolved so that ropefish could survive in low-oxygenated water. In fact, ropefish can even survive for a short time out of the water. 

The best water parameters for your ropefish is a water temperature of  between 22-28 °C, and slightly acidic, medium-hard water.