The reedfish, scientifically known as Erpetoichthys calabaricus, often referred to as the rope fish due to its rope-like appearance, is a captivating and unusual freshwater fish. Native to the slow-moving waters of West and Central Africa, specifically the Niger and Congo River basins, this species has gained popularity among aquarium enthusiasts for its unique morphology and relatively easy care requirements. This article provides a comprehensive guide to rope fish diet and care, covering everything from their natural history and habitat to their specific needs in captivity.
Natural History and Habitat
Discovered in 1865 by J. A. Smith, the reedfish belongs to the ancient Polypteridae family, with fossil records dating back 70 million years. Once widespread across central and northern Africa, they are now confined to the sluggish backwaters of the Niger and Congo rivers and their tributaries in west-central Africa.
Appearance and Behavior
Rope fish have an elongated, cylindrical body covered in overlapping, shingle-like scales, giving them a textured look. They can grow up to two feet in length. Their coloration is typically greenish-brown with yellow fins, which helps them blend into their natural environment. They possess small pectoral fins and a dorsal fin with 9-14 rays, which is often kept flat against the body. Ventral and caudal fins are essentially non-existent.
These fish are primarily nocturnal, becoming more active at night. However, they can be trained to be more active during the day by scheduling feedings when the aquarium lights are on. Rope fish are peaceful and get along well with other non-aggressive species.
One notable adaptation of rope fish is their ability to breathe atmospheric air. They possess a rudimentary lung-like structure that allows them to extract oxygen directly from the atmosphere. This adaptation is crucial for survival in oxygen-deficient waters. The reedfish must surface periodically to gulp air, as their gills are incapable of collecting sufficient oxygen from the water, no matter how well oxygenated the water is.
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Aquarium Setup
Tank Size
A minimum of a 50-gallon tank is recommended for housing a single adult rope fish. Given their potential size of up to 2 feet, floor space is more important than height. A longer and wider tank provides ample room for swimming and exploration. Each additional ropefish requires 10-15 extra gallons.
Substrate and Decorations
A naturalistic approach is best for decorating a rope fish aquarium. A 2- to 3-inch layer of fine-grained aquarium sand should be placed at the bottom of the tank. This allows the fish to burrow and reduces the risk of injury from ingested particles.
The tank should be heavily planted with species like Java fern, crystalwort, corkscrew Vallisneria, and Amazon sword. Top-growing plants such as water lettuce and water hyacinth can also be used, but not in excess, as they must not be allowed to completely cover the water’s surface. Sunken driftwood and commercially manufactured aquarium decorations, such as acrylic or ceramic hides and caves, are also recommended.
Lighting
Since rope fish are primarily nocturnal, they have little tolerance for excessively bright lights. Lighting should be sufficient to stimulate plant growth, with daily cycles of 8 to 10 hours.
Water Parameters
Rope fish are hardy but require specific water conditions to thrive. The ideal temperature range is 73° to 82°F (22-24°C), with a pH of 6.0 to 7.5 and a hardness level of up to 20 dKH. Sudden pH swings should be avoided. Ammonia and nitrite levels should be maintained at 0 ppm.
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Preventing Escapes
Rope fish are notorious escape artists. It is essential to secure the aquarium with a tight-fitting lid, ensuring that there are no gaps or holes. Weighted or locking lids are recommended, as adult rope fish are strong enough to lift unsecured lids. All filter apparatuses should be secured to prevent the fish from entering them.
Diet and Feeding
Rope fish are carnivores with a diet consisting of small crustaceans, insects, worms, and other tiny species. In captivity, they readily accept meaty foods such as bloodworms, chopped meat, frozen meat-based foods, insect larvae, and beef hearts. Live foods can also be offered for enrichment.
They rely heavily on their sense of smell to find food. Since rope fish are nocturnal, it is best to feed them once a day right before turning off the lights. Ropefish will eat most types of sinking pellets, but also require some live food in their diet. Frozen is fine. Try blood worms, and brine shrimp when small. When the ropefish grows, it will love some earthworms or meal worms. You may need to get a long pair of tongs to introduce food to your ropefish.
Tank Mates
Choosing appropriate tank mates is crucial for a peaceful aquarium environment. Rope fish are generally peaceful but may eat smaller fish. Suitable tank mates include larger, non-aggressive species such as Angelfish, Bala Sharks, Clown Loaches, Dwarf Gouramis, Glass Catfish, Pictus Catfish, Plecostomus, Rainbow Sharks, and Siamese Algae Eaters. Aggressive or territorial fish should be avoided. Small invertebrates like shrimp and snails may be consumed as food.
Health and Disease
Rope fish are hardy and resistant to many diseases, but maintaining good water quality is essential for their health. Signs of illness include behavioral changes, such as loss of appetite or reduced movement, as well as changes in color or the appearance of wounds. Ich, indicated by white spots on the scales, is a common issue that can be treated with salt or commercially available medications.
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Breeding
Breeding rope fish in captivity is rare and difficult, often requiring hormone injections. To encourage breeding, the water temperature can be slightly increased, and the tank should be well-planted. After around 70 hours, when juveniles hatch, it is important to move them away from adult rope fish since they might get eaten otherwise.