One look at the Tire Track Eel and it’s easy to see how they received their common name!

The Tire Track Eel Mastacembelus favus is one of the best known spiny eels. This fish owes its popularity not only to its color pattern, but also to a readily understood common name and its common availability. It has a large natural distribution and many variations to its color pattern, but most populations have the distinct ‘tire track’ or ‘zig zag’ type markings.

Although not considered to be true eels, the body shapes of all members of the spiny eel family, Mastacembelidae, are definitely eel-like. The Tire Track Eel has an elongated body and a long snout. Its background color is tan to light brown with irregular ‘tire track’ like markings along the entire length of its body that reach from the top of its back down to its belly. It is also called Tiretrack Eel, Zig Zag Eel, and White Spotted Spinyeel.

A favorite from Asia, M. favus is perhaps the most frequently imported of the spiny eel species. This is very attractive little fish when it is first acquired, usually at about 6 – 8 inches in length. It is a durable but rather shy fish. It gets along well in a community tank but does need hiding places for retreat. It is peaceful with its tank mates unless they are small and will fit in its mouth, and then they become snacks. When purchasing this spiny eel be aware that this fish will grow. It can reach close to 2 1/2 feet in length so adults will require a very large aquarium.

The Tire Track Eel is often misidentified in both published literature and in the aquarium industry as a different species, its close relative the popular Zig Zag EelMastacembelus armatus, which is also from Asia. Both of these eels are recognized and named for their distinct, irregular dark black markings. With ‘tire track’ or ‘zig zag’ type markings both bear the common names of Zig Zag Eel and Tire Track Eel.

The term “tire track eel’ can get rather confusing. Several spiny eels are often mis-identified because they are called Tire Track Eels. It is a common name that is used for 3, sometimes 4 different species. Besides being used for these two species M. armatus and M. favus, it is also a common name used for the Half-banded Spiny EelMacrognathus circumcinctus, and occasionally for the Black Spotted EelMastacembelus dayi.

These two popular spiny eels, M. armatus and M. favus, are often mis-identified because they are so similar looking when offered for sale as juveniles. But despite their very similar appearances, they do have some recognizable differences. Overall their coloration is quite similar, but the placement of the reticulated patterning on the body is the most distinguishing element.

The Tire Track Eel M. favus discussed here has a series of irregular dark markings along the entire length of its body, reaching from the top of its back down to its belly. The Zig Zag Eel is also marked along the entire length of its body, but the pattern is strong on the upper two thirds of its body, leaving the lower belly portion mostly plain. Another difference between these two that may not be so readily apparent when purchasing is their ultimate adult size. The Tire Track Eel can get up to about 28 inches long (70 cm) while the Zig Zag Eel will ultimately be quite a bit larger reaching, up to 35 inches (90 cm). It is good to know which fish you are getting!

Scientific Classification


Tiretrack Eel – Quick Aquarium Care

Aquarist Experience Level:Intermediate
Aquarium Hardiness:Moderately Difficult
Minimum Tank Size:125 gal (473 L)
Size of fish – inches27.6 inches (70.00 cm)
Temperature:72.0 to 82.0° F (22.2 to 27.8&deg C)

Habitat: Distribution / Background

The Track Eel Mastacembelus favus was described by Hora in 1924. They are found in Southeast Asia including India, Myanmar, Thailand and the entire Malay Peninsula. This species is listed on the IUCN Red List as least concern (LC) because it is common and widely distributed. Pollution, overfishing and other threats are considered insignificant at present. Other common names they are known by are Tiretrack Eel, Zig Zag Eel, and White Spotted Spinyeel.

They inhabit moving waters. They often bury themselves during the day in the gravel substrate, coming out at night to feed on insects larvae, worms, small fish, other aquatic invertebrates, plant matter, and detritus.

  • Scientific Name: Mastacembelus favus
  • Social Grouping: Solitary
  • IUCN Red List: LC – Least Concern


The body of the Tire Track Eel is elongated with a long snout. Both the dorsal and anal fins are extended and joined to the caudal fin. These fish will grow as long as 26 inches (70 cm), though some have been reported to reach up to 36 inches (91 cm). These larger fish may have been a mis-identification of the Zig Zag Eel Mastacembelus armatus. Spiny eels have a lifespan of 8-18 years.

Its background coloration is a tan to light brown. Along the entire length of its body, reaching vertically from its back to its belly, it is patterned with a series of irregular dark markings. These markings generally have a ‘tire track’ or ‘zig zag’ appearance which has been used as a common name for this fish as well as several other species of spiny eel.

This fish should not be confused with its very similar looking relative, the Zig Zag Eel M. armatus, which grows much larger reaching up to 35 inches (90 cm) in length. These two are often confused as juveniles because they are so similar looking. Despite their very similar appearances, there are recognizable differences. Overall their coloration is quite similar and they both have a series of irregular dark markings along the entire length of its body. But on the Zig Zag Eel M. armatus these markings are strongest on the upper two thirds with the belly portion mostly plain. On this eel, the Track Eel M. favus, they are more extreme irregular markings reaching from the top of its back down through its belly.

  • Size of fish – inches: 27.6 inches (70.00 cm) – This fish should not be confused with its very similar looking relative the Zig Zag Eel M. armatus which ultimately grows much larger, reaching up to 35 inches (90 cm).
  • Lifespan: 18 years – Spiny eels have a lifespan of 8-18 years.

Fish Keeping Difficulty

Eels are generally suggested for an aquarist with some experience rather than the beginner fish keeper. This eel can be a bit sensitive to change and usually takes awhile to get over its shyness. The first few weeks can be extremely difficult getting them to eat. They do require extremely pristine water. They have very small scales protecting their body so are prone to fungus and parasites and very sensitive to medications. These fish respond poorly to copper based medications, so these should be avoided. If cared for properly, these eels get fairly large and can live for a long time.

  • Aquarium Hardiness: Moderately Difficult
  • Aquarist Experience Level: Intermediate

Foods and Feeding

In nature the Tire Track Eels are omnivorous. They feed at night on insects larvae, worms, small fish, and other aquatic invertebrates, but they will also eat some plant matter and detritus. Like all spiny eels they prefer a diet of live and fresh frozen foods such as brine shrimp, black worms, earthworms or bloodworms.

Some Tire Track Eels can be trained to eat freeze dried brine shrimp or bloodworms but this is not something that can be counted on. They will also eat small fishes so make sure their tank mates are too large to be able to fit into their mouths. Eels only need to be fed a couple of times a week and some may refuse food offered more than that, then often eating only once every two or three weeks.

  • Diet Type: Omnivore
  • Flake Food: No
  • Tablet / Pellet: Occasionally – Not all specimens will accept processed foods.
  • Live foods (fishes, shrimps, worms): Some of Diet
  • Vegetable Food: Some of Diet – Some Tire Track Eels will accept vegetable matter, but this is fairly rare.
  • Meaty Food: Most of Diet
  • Feeding Frequency: Weekly – Eels only need to be fed a couple of times a week, and sometimes will eat even less.

Aquarium Care

The most important thing for these eels is that they always have clean and well-oxygenated water. Frequent water changes of about 30% a week are needed for this eel. With your weekly water change make sure to vacuum the gravel to remove all excess food and waster. but It’s best not to remove any bio film on rocks and decor. A magnet algae cleaner normally does a great job in keeping the viewing pane clear.

It is also helps to add efficient bottom cleaning tank mates to keep the bottom free from decaying foods inbetween cleanings. Be careful however, to add bottom cleaners after your eel is adjusted to its tank and is eating.

  • Water Changes: Weekly – Water changes of about 30% weekly.

Aquarium Setup

Tire Track Eels will spend most of their time on the bottom of the aquarium. This species of spiny eel can eventually grow to be quite large so plan accordingly. That cute little 4 inch fish may eventually grow to over 2 feet long! Keep small specimens up to 6 inches in a tank that is at least 36 inches long and about 35 gallons. Larger specimens will needing an even bigger area, tanks that are 48 inches in length or longer and 55 gallons up to 125 gallons will be necessary as they grow.

These fish require pristine water. They do best in a soft to medium water with good water movement that provides plenty of oxygenation. The tank water should turnover at least 10-15 times per hour. An undergravel filter is a great choice for these fish as it creates high oxygen through out the tank as well as reducing the waste. A canister filter or powerheads and airstones can be introduced to achieve proper flow and oxygenation.

It is recommended to have a tank set-up that resembles its natural habitat with plants, open areas to swim, and places for retreat. If their tank has a sand or fine gravel substrate, they may burrow into it. Make sure they have plenty of hiding places so they will feel secure in their new home. They do best in a dimly lit aquarium or one with floating plants to help subdue the light, they will uproot most other plants. Provide other decor such as rocks, caves, and roots to give it some dark areas to retreat. PCV tubing also makes great caves for these long eels. Provide a tight fitting lid as spiny eels are escape artists.

  • Minimum Tank Size: 125 gal (473 L) – This fish needs a tank long enough for it to stretch out in. Juveniles will be fine in about 35 gallons, but adults will need much larger.
  • Suitable for Nano Tank: No
  • Substrate Type: Sand/Gravel Mix – Provide a sand or fine gravel substrate so they can burrow.
  • Lighting Needs: Low – subdued lighting – In moderately lit tanks, provide floating plants to help subdue the light.
  • Temperature: 72.0 to 82.0° F (22.2 to 27.8&deg C)
  • Range ph: 6.5-7.8
  • Hardness Range: 5 – 15 dGH
  • Brackish: No
  • Water Movement: Strong
  • Water Region: Bottom – Tire Track Eels will spend most of their time on the bottom of the aquarium.

Social Behaviors

They are a nocturnal species but are generally peaceful and shy. They mostly ignore other tankmates although they may eat fish that are small enough to fit into their mouths. Some species of spiny eels can get territorial and aggressive with their own kind so a general rule of thumb is to keep them singly unless you plan to breed. In a large enough tank with many areas to hide multiples can be kept.

  • Venomous: No
  • Temperament: Semi-aggressive – This fish is generally shy although it will be highly aggressive with its own kind and is for this reason generally kept singly.
  • Compatible with:
    • Same species – conspecifics: Sometimes – Keep more than1 only for breeding, or if the tank is large enough for each to have undisturbed territories.
    • Peaceful fish (): Monitor – Tank mates need to be large enough to not be eaten.
    • Semi-Aggressive (): Monitor
    • Aggressive (): Monitor
    • Large Semi-Aggressive (): Monitor
    • Large Aggressive, Predatory (): Monitor
    • Monitor
    • Shrimps, Crabs, Snails: May be aggressive
    • Plants: Monitor – These eels will uproot most planted plants.

Sexual differences

Sexual differences are unknown and it is almost impossible to identify the sexes, though a mature female may be more full bodied.

Breeding / Reproduction

The Tire Track Eel has not been bred in captivity. Only a few spiny eels have been bred in the aquarium, possibly because they are generally kept singly rather than in a group where a male and female can find each other. Though it is not documented what makes them spawn, trying to emulate the bounty of the flood season can help stimulate breeding behavior. Feed more and higher quality food than you normally would and providing an influx of clean water. Their courtship lasts for several hours, where they chase each other and swim in circles.

The eggs are deposited among floating plants. They are sticky so will adhere to the plants and then hatch in 3 to 4 days. The fry becoming free swimming a few more days after that and should be fed nauplii. The fry are something of a challenge to raise as they are susceptible to fungal infections. Regular water changes and the use of an antifungal water treatment can help.

  • Ease of Breeding: Unknown – This fish has not been bred in the home aqarium, however it is presumed that their breeding process is similar to other Spiny Eels.

Fish Diseases

Eels are prone to diseases caused by parasites and fungus, so take caution when introducing these fish to an established tank. Eels are also very sensitive to medications used to treat many diseases; a separate hospital tank is needed. Very low water temperatures and condition changes can also cause stress to this fish which makes them even more prone to disease. Take great care when netting eels as they have very delicate and scraps can make them even more prone to disease.

The most common disease that an eel is susceptible to is Ich. Ich is short for Ichthyophthirius, also known as “white spot disease”. It is a parasite that can attack nearly all aquarium fishes, but you’ll find that Eels are often the first to be attacked. Take great care in treating ick as eels are very sensitive to the medications used to treat it. Often the dose is half of what is normally used. If nervous or unsure about medications, use Reef safe medications.

An outbreak of disease can often be limited to just one or a few fishes if you deal with it at an early stage. When keeping these sensitive types of fish, it is common to catch deteriorating water conditions and disease before other fish are affected. The best way to proactively prevent disease is to give your Tire Track Eel the proper environment and give them a well balanced diet. The closer to their natural habitat the less stress the fish will have, making them healthier and happy. A stressed fish will is more likely to acquire disease.

Anything you add to your tank can bring disease to your tank. Not only other fish but plants, substrate, and decorations can harbor bacteria. Take great care and make sure to properly clean or quarantine anything that you add to an established tank so not to upset the balance. It is recommended to read up on the common tank diseases. Knowing the signs and catching and treating them early makes a huge difference. For information about freshwater fish diseases and illnesses, see Aquarium Fish Diseases and Treatments.


The Tire Track Eel M. favus is commonly available and reasonably priced. Be aware when purchasing that the Tire Track Eel is often misidentified in its common name as the Zig Zag Eel M. armatus. As these two similar looking eels attain a much different adult size it is important to know which eel you are purchasing. The Tire Track Eel can grow to about 28″ in length while the Zig Zag Eel can reach up to 36″.



 Tire Track Eel (Image Credit: Adolsomee, Wikimedia Commons CC BY-SA 3.0 Unported)