TankBud

Tire-track eel

Mastacembelus armatus

Also known as Zig-zag eel, Tyre-track eel

FreshwaterFish

Tire-track eel (Mastacembelus armatus)
Adolsomee · CC BY-SA 3.0

Care at a glance

Temperature
75–82°F
24–28°C
pH
6.5–7.5
Adult size
27.6 in
70 cm
Minimum tank
119 gal
450 L
Temperament
Mostly peaceful
Social behavior
Solitary
Tankmates
With caution
Swim level
Bottom
Difficulty
Difficult
Breeding
No record
Rarity
Common
Family
Mastacembelidae
Origin
South and Southeast Asia (India, Bangladesh, Thailand, Indonesia, Vietnam)

Overview

Keep one per tank, since this eel is territorial with its own kind and will not share space peacefully with another. It is otherwise mostly peaceful but it is a nocturnal predator that will eat any fish small enough to swallow, so house it only with robust, larger species. It is a bottom dweller that needs that 450 liter footprint, sand to dig in, water from 24 to 28 C, and a pH between 6.5 and 7.5. Feed it after lights out with meaty foods like earthworms, frozen bloodworms, and prawn. It is scaleless and copper-sensitive, so avoid copper-based medications entirely.

In the wild

Tire-track eels live across South and Southeast Asia, in rivers and floodplains through India, Bangladesh, Thailand, Indonesia, and Vietnam. They spend the day partly buried in soft riverbed, so the substrate matters more than anything else. Give them a deep bed of soft sand they can burrow into, plenty of rockwork or pipes for cover, and a tank of at least 450 liters for an adult this size. Keep the water between 24 and 28 C with a pH from 6.5 to 7.5, and run a tight, gap-free lid since they are determined escape artists.

Good to know

This is a spiny eel in the family Mastacembelidae, and it is large, commonly reaching 60 to 90 cm with adults around 70 cm. There is no reliable home breeding record for the species, so plan on it as a single long-term fish rather than a breeding project. It is a hardy, long-lived predator when its needs are met. Most fish in the trade are wild caught.

Did you know

The "tire track" name comes from the wavy, broken pattern running down the body, and no two eels carry quite the same markings. The long snout works like a probe, sniffing through sand for buried food, and the eel often sits with just its head poking out of the substrate, watching the tank until it goes dark.

Common questions

What size tank does a Tire-track eel need?

A Tire-track eel needs at least 119 gal (450 L). It spends most of its time in the bottom.

What temperature and pH does a Tire-track eel need?

A Tire-track eel is comfortable at 75–82°F (24–28°C) with a pH of 6.5–7.5.

How big does a Tire-track eel get?

An adult Tire-track eel reaches about 27.6 in (70 cm).

Related species