Ropefish
Erpetoichthys calabaricus
advanced careOverview
The ropefish (Erpetoichthys calabaricus) is a living oddball — a long, eel-like, air-breathing fish from West African waters that can reach 40 cm and live two decades. It is peaceful, gentle and fascinating to watch as it snakes through the tank, but it comes with two firm rules: it escapes through the smallest gap, and it eats any fish small enough to swallow. Give it a big, sealed tank and suitable company and it is a hardy, long-lived centrepiece for the dedicated keeper.
Tank & water
Prioritise floor space and length. A ropefish needs at least 200 litres (55 gallons) with a long footprint, and more for a group. See our large-tank guide.
- Temperature: 22–28 °C from a robust, guarded heater.
- Water: pH 6.5–7.5, soft to moderately hard; test with a kit.
- Gentle filtration: a well-sized filter with moderate flow, plus regular water changes.
- Aquascape: soft sand (they burrow), plenty of caves, wood and pipes to hide in, and a gap of air at the surface so they can breathe.
Feeding
Ropefish are carnivores and slow, nocturnal, scent-driven hunters. Feed meaty frozen and live foods — bloodworm, earthworms, prawn pieces, mussel and similar — offered in the evening once the lights are low. They are poor competitors, so make sure faster, more active tankmates don’t strip the food before the ropefish finds it. Most ignore dry foods, so plan on frozen and live.
Tankmates
Peaceful toward fish too big to eat, so choose calm, medium-to-large companions — larger peaceful cichlids, bigger barbs, gouramis and similar. Never house them with small fish, fry or shrimp, all of which are food. Avoid very boisterous or aggressive tankmates that will out-compete a slow feeder. A small group of ropefish will happily share caves. Check the load with how many fish in an aquarium.
Common mistakes to avoid
- Any gap in the lid — the number-one cause of dead ropefish
- Housing them with small fish or shrimp that become night-time snacks
- Fast, greedy tankmates that strip food before a slow ropefish finds it
- No surface air gap, leaving an air-breather unable to reach the surface
Get the sealed lid, the space and the diet right, and the ropefish is a genuinely long-lived, low-drama oddball that can share your tank for well over a decade.
Ropefish — frequently asked questions
Do ropefish really escape from tanks?
Yes — this is the single most important thing to know. Ropefish are expert escape artists that squeeze through tiny gaps around lids, filters and cables and can die on the floor. You need a completely tight-fitting lid with every opening sealed or covered. An open-topped or loosely covered tank is not safe for a ropefish.
Are ropefish air-breathers?
Yes. Ropefish have a primitive lung and gulp air from the surface, which lets them survive in low-oxygen water and even out of water for a while if kept damp. They must be able to reach the surface, so leave a gap of air above the water line — but keep that gap sealed against escapes.
Do ropefish eat other fish?
They will eat any fish or shrimp small enough to swallow. Ropefish are peaceful toward larger tankmates but are slow, nocturnal hunters that hoover up small fish, fry and invertebrates at night. Keep them only with peaceful fish too large to be eaten and too calm to steal all the food.
Found your model? Buy it at the right price.
UniverTrack tracks the real price of your aquarium gear across several retailers, spots fake discounts and warns you when it's genuinely the right moment to buy — with an AI assistant to guide you.