Black Rope Fish Facts

Rope fish (Erpetoichthys calabaricus) are often called "snake fish" or "reed fish" because of their long, snake-shaped bodies. Native to Africa near the Cameroon and Niger Rivers, rope fish belong to the Polypterdae family. These fish can be purchased at aquarium stores and can be kept in household aquariums.

  1. Misconceptions

    • There are no black rope fish. Caecilians are commonly mistaken for ropefish because of their long, eel-shaped bodies. Caecilians are an amphibian from the genus Typhlonectes. In aquarium stores, they are often called "rubber eels" or "black eels," but they are not eels at all. Caecilians come in black and a variety of brilliant colors. They are native to South America but can be kept in an aquarium with proper care.

    Characteristics

    • Rope fish are typically greenish-brown on the topside and a yellow on the belly side with black spots on the pectoral fins. Rope fish are shaped like an eel and can grow up to 16 inches long. Extending from their nostrils are two sensory-like organs. Rope fish have no ventral fins, but they do have many dorsal fins on their backs. The anal fin can be found near the caudal fin, which is located on the bottom side of the fish. Female and male rope fish look alike, but the males have more rays in their anal fins.

    Anatomy

    • Rope fish have certain body features from their ancestral fish relatives. For example, they have a swim bladder that is split in two sections. The right section is larger than the left. The swim bladder in orientation is similar to that of the lungs found in higher order vertebrates. The swim bladder acts as the breathing organ. Rope fish have gills, but require air and will drown if an air supply is not available.

    Diet

    • In natural habitats, rope fish eat crustaceans, smaller fish, worms and bugs. If kept as a pet in an aquarium, bloodworms and live frogs are recommended. Rope fish naturally like to feed on live food, but they can be trained to eat frozen meat products. For nonliving food, diced up seafood, including fish can be used to feed rope fish. Beef heart can also be used. Certain rope fish will not eat dried fish food.

    Pets

    • Since rope fish can grow up to 16 inches in length, aquarium shops recommend a tank size at a minimum of 300 liters. The aquarium should have a lid, as rope fish can escape if the tank is left uncovered. Recommended water temperature is between 72 to 82 degrees F. Abundant rocks, caves and other hiding places are suggested. Rope fish are predominantly nocturnal, but have been seen swimming in tanks during the day. Rope fish are peaceful by nature and can cohabitate with other rope fish in an aquarium.