
Tire Track Eel
Mastacembelus armatus
Family: Mastacembelidae • Origin: Various
Tire Track Eel (Mastacembelus armatus) is a semi-aggressive other reaching 36 inches. Can be kept singly. Minimum tank: 125 gallons.
Is Tire Track Eel Right for Your Tank?
Tire Track Eel is a moderate-care fish rated "advanced" (3/5). Suitable for hobbyists with some experience who can maintain stable water parameters. At 125+ gallons minimum, these are large-tank fish. Make sure you have the space and filtration before committing.
Tire Track Eel is semi-aggressive — they can live with others but may bully smaller or slower fish. Choose tank mates carefully. They are territorial — provide adequate hiding spots and maintain enough space to reduce aggression. Expected lifespan: 20 years with proper care.
Common Mistakes with Tire Track Eel
Relying on a heater without a thermometer
Tire Track Eel needs 72–82°F. Heaters malfunction or drift over time — always use a separate thermometer to verify. Temperature swings of even 3–4°F can trigger stress and disease, particularly ich.
Putting them in a tank under 125 gallons
Many beginners underestimate tank size needs. Tire Track Eel requires at least 125 gallons — ideally 188. Cramped tanks lead to stunted growth, aggression, and poor water quality.
Housing with peaceful nano fish
Tire Track Eel is semi-aggressive and territorial — small, peaceful species like neon tetras, endlers, or celestial pearl danios will be stressed, bullied, or eaten. Choose tank mates that can hold their own.
Care Tips
- • Max size: 36"
- • Temp: 72-82°F
- • pH: 6.5-7.5
- • Can be kept alone
- • semi-aggressive temperament
Feeding: Standard carnivore diet for Mastacembelidae.
Compatibility Notes: Typical semi-aggressive Mastacembelidae species.
Tank Setup & Water Parameters
Tank Requirements
- Minimum Tank Size
- 125 gallons
- Recommended Tank Size
- 188 gallons
- Swimming Level
- bottom
Water Parameters
- Temperature
- 72–82°F
- pH Range
- 6.5–7.5
- Hardness (dGH)
- 5–15
- Water Type
- freshwater
Behavior & Temperament
- Temperament
- semi-aggressive
- Aggression Level
- 3/5
- Schooling
- No
- Territorial
- Yes
- Fin Nipper
- No
- Predatory
- Yes
- Diet Type
- carnivore
- Growth Rate
- fast
Typical semi-aggressive Mastacembelidae species.
Breeding
- Breeding Type
- egg layer
- Breeding Difficulty
- difficult
- Lifespan
- 20 years
Ideal For
Compatible Tank Mates
View all →
Neon Tetra
Paracheirodon innesi

Ember Tetra
Hyphessobrycon amandae

Rummy Nose Tetra
Hemigrammus rhodostomus

Black Neon Tetra
Hyphessobrycon herbertaxelrodi

Serpae Tetra
Hyphessobrycon eques

Black Skirt Tetra
Gymnocorymbus ternetzi
Similar Species

Fire Eel
Mastacembelus erythrotaenia

Freshwater Stingray
Potamotrygon motoro

Rope Fish
Erpetoichthys calabaricus

Dragon Goby
Gobioides broussonnetii