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title: "Rope Fish: The Complete Care, Tank & Escape-Proofing Guide" description: "The definitive rope fish (Erpetoichthys calabaricus) care guide: the air-breathing 'reedfish' — the absolute need for an escape-proof tank, carnivore diet, big tank, and tank mates." slug: rope-fish commonName: Rope Fish scientificName: Erpetoichthys calabaricus family: Polypteridae order: Polypteriformes difficulty: Intermediate temperature: "76–82°F (24–28°C)" ph: "6.5–7.5" hardness: "5–18 dGH" lifespan: "15–20 years" maxSize: "15 inches (38 cm)" minTankSize: 55 origin: "West & Central Africa" publishedAt: "2026-06-05"

Rope Fish: The Complete Care, Tank & Escape-Proofing Guide

The rope fish is one of the most unusual and fascinating animals in the freshwater hobby — a slender, snake-like, air-breathing "living fossil" that glides through the tank like an aquatic serpent and bonds with its keeper over a remarkably long life. Erpetoichthys calabaricus (the rope fish or reedfish) is peaceful, hardy, and characterful, but it carries one absolute, non-negotiable requirement: it is among the most determined escape artists in the entire hobby, and an open tank will lose it.

This guide is the complete reference: rope fish biology, the critical escape-proofing, its carnivore diet, tank size, and tank mates.

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Species Overview

The rope fish (Erpetoichthys calabaricus) is an ancient African fish in the family Polypteridae (the bichirs and reedfish), reaching about 38 cm (15 inches). Its body is long, slender, and snake-like — eel-shaped but a true fish — covered in armoured ganoid scales, with a row of small dorsal finlets and pectoral fins it uses to "walk" along the bottom. It moves with a graceful, serpentine glide and explores constantly.

The rope fish is a peaceful, hardy, intelligent, long-lived (15–20 years) air-breather with genuine personality — it recognises its keeper, can be hand-fed, and is endlessly engaging. It's rated intermediate for three reasons: its large adult size (needing a big tank), its carnivore diet (it won't eat flake and needs meaty foods), and — above all — its extreme escape-artist behaviour (it must have an utterly escape-proof tank). As a primitive air-breather it has a functional lung and must reach the surface to gulp air. For the keeper who can provide a big, sealed, peaceful tank, the rope fish is one of the most unusual and rewarding fish in the hobby.

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Natural History and Origin

Erpetoichthys calabaricus is native to slow, warm, often low-oxygen freshwaters of West and Central Africa — sluggish rivers, swamps, and floodplains, frequently soft and warm. As a member of the ancient Polypteridae, it's a "living fossil" retaining primitive features, including a paired lung that lets it breathe atmospheric air — an adaptation to its low-oxygen habitat, and the reason it must reach the surface to gulp air (and can even survive out of water for a time if kept moist, which fuels its escaping).

In the wild, rope fish are nocturnal predators, hunting small fish, worms, crustaceans, and insects among vegetation and structure using a keen sense of smell (their eyesight is poor). This predatory, scent-driven, nocturnal hunting defines their captive diet (meaty foods, often fed in the evening) and their tank-mate limits (they eat small fish). Their snake-like body, air-breathing, and ability to survive briefly out of water make them exceptional escape artists — they squeeze through tiny gaps and "rope" their way out of any opening. Their primitive biology, predatory nature, and escaping all stem from this ancient, low-oxygen, African swamp lineage.

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Water Parameters

Rope fish are hardy and adaptable to a range of soft-to-moderate, warm water, reflecting their swamp origins. As an air-breather they tolerate low oxygen, but they still need clean, stable, cycled water. Confirm cycling with the nitrogen cycle tracker and check values with the water parameters reference. They have reduced scaling and can be sensitive to some medications (especially copper) and salt, so medicate cautiously. Their hardiness makes them forgiving of most stable conditions.

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Tank Setup Guide — Escape-Proofing Is Everything

Tank size

A rope fish needs a minimum of 55 gallons (210 litres), with larger better for an adult or a group — they reach 38 cm and appreciate a long footprint and room to explore. They're social with their own kind and can be kept in groups given space.

The escape-proof lid — absolutely critical

This is the single most important aspect of rope fish keeping: the tank must be completely, utterly escape-proof. Rope fish are legendary escape artists that squeeze through the tiniest gaps — filter cutouts, feeding holes, the gap around a lid, anywhere — and "rope" their way out, then desiccate on the floor (though they can survive a surprising while out of water if found in time). You must have a tight-fitting, weighted lid with every single gap sealed or covered (mesh over cutouts, no openings). More rope fish are lost to escaping than to anything else. Do not keep a rope fish without obsessively sealing the tank.

Aquascape, filtration, surface access

Provide soft substrate, hiding places (caves, driftwood, PVC, plants) for these nocturnal, shy-at-first fish to shelter in, and ensure easy access to the surface to breathe air (don't fill to the brim with no air gap — but seal the lid above that gap). Use reliable filtration with moderate flow. A sealed, structured, peaceful tank with surface access is ideal.

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Feeding Guide

Rope fish are carnivores that hunt by smell, mostly at night — they won't eat flake and need meaty foods.

What to feed

• Frozen and live meaty foods — bloodworm, blackworms, earthworms, prawns/shrimp pieces, mussel, and similar.
• Sinking carnivore pellets — some rope fish learn to take them; useful as a supplement.
• They hunt by scent, so smelly, meaty foods work best.

How often

Feed every 1–2 days, ideally after lights-out (they're nocturnal and hunt by smell, and fast daytime fish can steal food before the slow, poorly-sighted rope fish finds it). Ensure the rope fish actually gets fed — in a community tank, target-feeding meaty foods near it helps. Avoid feeder fish as a staple (poor nutrition, disease risk). A healthy rope fish is well-fed (not thin), active at night, and exploring. Their poor eyesight and scent-based hunting mean patience and proper meaty feeding are key.

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Behaviour and Tank Mates

Rope fish are peaceful, social, nocturnal, and intelligent — they glide and explore (especially after dark), shelter in caves and structure by day, and bond with their keeper, even hand-feeding once settled. They're social with their own kind and do well in groups given space. They're peaceful toward fish too large to eat.

The key tank-mate rule is their predatory nature: rope fish eat any fish small enough to swallow (their wide mouth manages surprisingly large prey), so tank mates must be peaceful and too large to be eaten — but not aggressive (boisterous or fin-nipping fish stress and harass the slow, gentle rope fish, and fast feeders outcompete it). Good tank mates include larger peaceful fish like angelfish, silver dollars, larger gouramis, bristlenose pleco, and other calm, medium-large community fish, plus other bichirs/rope fish. Avoid small fish (eaten), aggressive cichlids, and fin-nippers. Use the compatibility checker.

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Breeding Guide

Rope fish are rarely bred in home aquaria — captive breeding is uncommon and not well-established, with most rope fish being wild-caught. Sexing is subtle (males may have a broader anal fin), and the triggers and conditions for spawning aren't reliably reproduced at home. Occasional captive spawnings have been reported with hormone induction or specific conditions, but it's not a practical home project.

For keepers, the rope fish is a long-lived, fascinating display animal to enjoy rather than breed. Choosing a healthy, well-started specimen and providing a sealed, peaceful, well-fed tank is the practical focus.

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Health and Disease

Rope fish are hardy and long-lived, with the leading "health" risk being escape rather than disease.

Escape and desiccation is the number-one cause of rope fish loss — an inadequately-sealed tank loses the fish (see Tank Setup). Starvation can occur if the slow, nocturnal, poorly-sighted rope fish is outcompeted — feed it properly, after dark. Ich and bacterial/fungal infections can affect them; they're sensitive to copper and salt and some medications, so medicate cautiously at reduced doses. Injuries from sharp décor on their soft underside. Otherwise they're remarkably tough, long-lived fish.

Prevention: an utterly escape-proof tank (the priority); a large, peaceful, structured tank with surface access; proper meaty feeding after dark; careful medicating; and quarantine of new (wild-caught) arrivals. Given a sealed tank and good feeding, rope fish are hardy companions for 15–20 years.

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Interesting Facts

• A living fossil that breathes air. As an ancient polypterid, the rope fish has a functional lung and must gulp air at the surface — and can survive a while out of water.
• The ultimate escape artist. Its snake-like body and air-breathing let it squeeze through tiny gaps and escape any unsealed tank — escape-proofing is essential.
• It hunts by smell. With poor eyesight, the rope fish finds food by scent, hunting mostly at night — feed smelly meaty foods after dark.
• Long-lived and personable. It can live 15–20 years, recognises its keeper, and hand-feeds — closer to a pet than a typical fish.
• A peaceful predator. Gentle toward fish too large to eat, but it will swallow any small tank mate.

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Bringing It Together

The rope fish is one of the most unusual, fascinating, and long-lived fish in the hobby — an air-breathing "living fossil" that glides through the tank like a serpent and bonds with its keeper over two decades. The one absolute rule is escape-proofing: rope fish are extreme escape artists, and you must seal every gap of the tank obsessively, or you will lose it. Beyond that, give it a large (55 gallons-plus), peaceful, structured tank with surface access, a meaty carnivore diet fed after dark, and tank mates too large to eat but not aggressive — and it will reward you with years of serpentine charm and hand-feeding. Mind its medication sensitivity and predatory appetite, choose healthy stock, and never keep it in an unsealed tank. It pairs with larger peaceful fish like angelfish, silver dollars, and a bristlenose pleco. Plan the build with the AI Tank Blueprint generator and the compatibility checker.