Fire Eel - Mastacembelus erythrotaenia

Fire Eel (Mastacembelus erythrotaenia)

The Fire Eel is a striking and unusual freshwater fish recognised for its elongated eel-like body, dark base colour and vivid red to orange markings along the sides and fins. Despite its common name, it is not a true eel but a member of the spiny eel family. Intelligent, secretive and predatory, this species requires a very large, mature aquarium with soft substrate, secure hiding places and carefully selected tankmates.

Common Name:
Fire Eel, Fire Spiny Eel

Scientific Name (Latin):
Mastacembelus erythrotaenia

Maximum Size:
Approximately 80–100 cm

Water Type:
Freshwater

Origin / Natural Habitat:
The Fire Eel originates from freshwater habitats in Southeast Asia and is associated with rivers, streams, floodplain waters and slow-moving areas containing soft substrate, submerged wood and dense cover.

It spends much of its time close to the bottom, where it may bury partially into sand or shelter beneath roots and rocks.

Water Parameters:
Temperature: 24–28°C
pH Range: 6.5–7.5
Hardness: Soft to Moderate
Ammonia/Nitrite: 0 ppm
Nitrate: Kept low and stable

Temperament:
Peaceful to Semi-Aggressive / Predatory

The Fire Eel is generally peaceful towards fish that are too large to be viewed as prey.

However, small fish, shrimp and other suitably sized inhabitants may be eaten, particularly during nocturnal feeding.

Diet:
Carnivore / Predator

The Fire Eel naturally feeds on worms, crustaceans, insect larvae and other small aquatic animals.

In the aquarium, offer a varied diet including frozen or live bloodworm, earthworms, prawns, mussel, cockle, krill and other suitably sized meaty foods.

Many specimens prefer feeding after the aquarium lights have dimmed and may take time to become confident enough to accept food in the open.

Minimum Tank Size:
Approximately 700 litres for an adult specimen

A very large aquarium with substantial floor space is essential due to the species' considerable adult size and elongated body shape.

Behaviour & Activity:
The Fire Eel is primarily a bottom-dwelling fish and may remain hidden for much of the day, becoming more active during quieter periods and towards evening.

It frequently investigates caves, driftwood and substrate and may partially bury itself in soft sand.

Provide numerous secure hiding places while leaving enough unobstructed floor space for the fish to move comfortably.

Community Suitability:
Predator / Large Community Fish

The Fire Eel can be maintained with suitably large, peaceful or moderately robust fish that will not harass it.

Suitable tankmates may include larger barbs, rainbowfish, peaceful catfish and other substantial species that are too large to be swallowed.

Avoid very small fish, ornamental shrimp and aggressive species likely to injure or continually disturb the eel.

Special Requirements or Care Notes:
Provide a very large, mature aquarium with soft sand or another smooth substrate.

Avoid sharp gravel, as Fire Eels frequently burrow and can damage their skin on rough material.

Caves, pipes, driftwood and secure rockwork should be provided to create suitable hiding places.

The aquarium must have a tightly fitted lid with all openings secured, as spiny eels are excellent escape artists and can squeeze through surprisingly small gaps.

Strong biological filtration and regular partial water changes are essential for maintaining excellent water quality.

Newly introduced specimens may be shy and reluctant to accept prepared foods, so careful feeding observation is important.

Its enormous adult size and long-term space requirements should be fully considered before purchase.

Suitable for:
Experienced

Availability:
Regularly available

All images are a visual representation of the fish you will receive, made to be as accurate as possible. Please note that Mother Nature is a wonderful thing, and variation in patterns and colours will occur — that is part of the unique beauty of these animals.