Ropefish

Care at a glance

Overview

The ropefish is a peaceful, eel-shaped, night-active fish that spends the day tucked under wood and rockwork and glides out to forage after dark. It is gentle toward tankmates its own size but will eat very small fish and shrimp, so choose companions it cannot swallow. It is an accomplished escape artist, so the tank needs a tight lid with every gap sealed, including around filters and cords. Provide soft sand it can nose through and plenty of cover. Feed meaty foods such as earthworms, prawns, and mussel in the evening. This long fish needs a tank of at least 540 liters.

In the wild

Erpetoichthys calabaricus lives in slow, warm freshwaters of West and Central Africa, from Nigeria through the Congo basin to Angola, in vegetated rivers, swamps, and estuaries that are often low in oxygen. Its ability to breathe air lets it thrive there. Recreate this with soft substrate, dense cover from wood and plants, and gentle flow. Keep the temperature between 23 and 30 degrees Celsius and the pH from about 6 to 8. Leave open air above the water so it can surface to breathe.

Good to know

The ropefish, also called the reedfish, belongs to Polypteridae, an ancient lineage of ray-finned fish, and commonly reaches about 37 centimeters, sometimes longer. It has a slender, snake-like body covered in hard, glossy ganoid scales and lacks the pelvic fins its bichir relatives keep. Like all polypterids it has paired, lung-like swim bladders and breathes atmospheric air. Aquarium spawning is rarely recorded.

Did you know

The ropefish is a determined escape artist. It can breathe air and survive out of water for hours as long as it stays damp, so it will slip through any small gap in the lid and travel a surprising distance across the floor.

Related species

• 

  Barred bichir

  Polypterus delhezi

  13.8 in (35 cm)53 gal (200 L)75–86°F (24–30°C)

• 

  Marbled bichir

  Polypterus palmas

  13.8 in (35 cm)53 gal (200 L)75–82°F (24–28°C)

• 

  Senegal bichir

  Polypterus senegalus

  13.8 in (35 cm)143 gal (540 L)75–82°F (24–28°C)
• West African Bichir

  Polypterus retropinnis

  13.8 in (35 cm)53 gal (200 L)77–82°F (25–28°C)

• 

  Ornate bichir

  Polypterus ornatipinnis

  21.7 in (55 cm)172 gal (650 L)77–82°F (25–28°C)

• 

  Saddled bichir

  Polypterus endlicherii

  25.6 in (65 cm)151 gal (570 L)77–84°F (25–29°C)