Tire track Eel (Mastacembelus armatus) — 8-10cm

Overview

The Mastacembelus armatus, widely known as the Tire Track Eel or Zig-Zag Eel, is a striking, nocturnal spiny eel native to freshwaters of South and Southeast Asia. Growing to an impressive 90 cm in captivity, this species requires a secure, spacious aquarium with robust filtration and meaty foods. Its bold tire-track markings and fascinating burrowing behavior have made it a favorite among enthusiasts of large, oddball fish for sale UK. At Tropical Fish Co, we supply healthy juveniles that adapt well to aquarium life and reward attentive care with years of engaging, active behavior.

Appearance and Coloration

Mastacembelus armatus displays a robust, elongated body adorned with distinctive dark brown or black zig-zag markings that resemble tire tracks running along a golden-brown or olive base color. The patterning is bold and consistent from juvenile to adult. The head is slightly compressed with a pointed snout and small eyes. The dorsal and anal fins run almost the full length of the body, giving the fish a ribbon-like appearance. The body is muscular and capable of powerful burrowing movements. Under subdued lighting, the tire-track pattern is particularly striking.

Natural Habitat and Distribution

This species inhabits river systems across the Indian subcontinent and parts of South and Southeast Asia. It favors slow to moderate-flowing rivers, lakes, and floodplains with soft substrate, submerged logs, and abundant hiding places. Water conditions are typically warm (24–28 °C), neutral to slightly acidic, and well-oxygenated. Mastacembelus armatus is primarily nocturnal, hiding during the day in burrows, root tangles, or under rocks. At dusk, it emerges to hunt for small fish, worms, and invertebrates. The natural environment is dimly lit with moderate current and a soft mud or sand substrate.

Aquarium Setup and Décor

A 450-litre aquarium is the minimum for a single adult Tire Track Eel. Provide soft sand or fine substrate for burrowing, plenty of hiding places such as PVC pipes, caves, and driftwood, and subdued lighting. Avoid sharp-edged décor, as the eel's skin is sensitive and can be damaged. A tight-fitting lid with no gaps is essential, as this species is an excellent escape artist and will squeeze through surprisingly small openings. Secure all equipment and décor, as the eel may dislodge items while burrowing. Sensitive to poor water quality, so maintain excellent filtration and perform regular water changes.

Feeding and Nutrition

Mastacembelus armatus is primarily carnivorous. Offer meaty foods such as earthworms, bloodworms, blackworms, shrimp, chopped fish, and quality sinking carnivore pellets. Many individuals need live or frozen foods at first and should be fed in the evening when they are most active. Feed once daily, ensuring food reaches the substrate. This species is a predatory feeder and will consume any tankmate small enough to be swallowed. Avoid overfeeding, as uneaten food can degrade water quality. Once acclimated, some individuals will accept high-quality sinking pellets.

Behaviour and Social Structure

The Tire Track Eel is primarily nocturnal and semi-aggressive. It hides during the day, often buried in the substrate with only the head visible, and emerges at dusk to hunt. This species is solitary and territorial, especially toward conspecifics. It may prey on small tankmates and can be assertive at feeding time. Despite its size and predatory nature, it is not overly aggressive toward tankmates of similar size. The eel is a powerful burrower and will constantly rearrange substrate and décor. Handle with care; the spines can inflict painful wounds.

Compatible Tank Mates

Ideal companions include large, peaceful fish that cannot be swallowed such as robust medium-to-large barbs (tinfoil, rosy), large gouramis (pearl, three-spot), large rainbowfish (Boesemani, turquoise), and large peaceful catfish that are too big to be eaten (large Synodontis, large Plecostomus). Avoid housing with small fish, shrimp and other small invertebrates, very aggressive cichlids, fin-nipping species, or any tankmate small enough to be swallowed. Do not house with other spiny eels or highly territorial bottom-dwellers.

Breeding in the Aquarium

Breeding in home aquaria is uncommon; little reliable captive-breeding information is available. Spawning likely requires large, mature fish and seasonal environmental cues such as temperature fluctuations and increased rainfall simulation. Sexual dimorphism is subtle and not well documented. If breeding is attempted, provide a very large aquarium, excellent water quality, and seasonal conditioning. Fry, if produced, require specialized care and high-protein micro-foods.

Why Buy from Tropical Fish Co

At Tropical Fish Co, every Tire Track Eel is quarantined, health-checked, and acclimated to UK water conditions before dispatch. We source our fish from reputable suppliers who prioritize ethical collection and sustainable practices. Our livestock arrives in insulated packaging with heat packs during colder months, ensuring safe transit. With decades of combined fishkeeping experience, our team is available to answer questions about care, compatibility, and tank setup. Whether you're building a large oddball aquarium or expanding an established collection, we're here to support your success. Order with confidence and enjoy premium freshwater fish delivered to your door.