Tire Track Eel (Mastacembelus armatus) Care Guide
Mastacembelus armatus is a large Asian spiny eel reaching about 90 cm, marked with a winding tire-track pattern and needing a big tank.
Compiled by Aquairi from published sources · Published · Updated
Overview
Mastacembelus armatus, the tire-track or zig-zag eel, is a large elongated freshwater fish of the family Mastacembelidae from Asia. It is marked with a winding dark pattern on the flanks and reaches up to about 90 cm in the wild, though it is typically smaller in captivity.
Taxonomy
- Family: Mastacembelidae
- Genus: Mastacembelus
- Scientific name: Mastacembelus armatus
- Common synonym: Marbled Spiny Eel
Habitat
FishBase records the species from Pakistan to Vietnam and Indonesia. It inhabits highland streams, lowland wetlands, still waters and rivers with sandy, pebbly or rocky beds, occasionally burying in fine substrate and entering flooded forests seasonally. It is found in freshwater and brackish water and is potamodromous.
Tank requirements
- Minimum tank volume: 600 L
- Temperature: 24-28 °C (75-82 °F)
- pH: 6.5-7.5
- GH: 5-15 °dGH
- Lifespan: 10-18 years
- Substrate: sand
Diet
The tire-track eel is a nocturnal carnivore. FishBase reports it consumes benthic insect larvae, worms and some submerged plant material; Wikipedia adds small fish, mollusks and crustaceans. In the aquarium it is offered live and meaty foods roughly every two to three days.
Compatibility
It is a semi-aggressive bottom-dweller, described as aggressive toward members of the same family but peaceful toward other species. Mid-size robust fish make suitable companions, while smaller fish and shrimp should be avoided.
Breeding
In the wild it spawns beneath rocky substrates during the monsoon season. There are no widely documented successful captive-breeding programs.
Conservation status
IUCN Red List: Least Concern (assessed 2019).
Breeding the Tire Track Eel (Mastacembelus armatus)
Overview
The Tire Track Eel (Mastacembelus armatus) is a large Asian spiny eel of riverine systems across the Indian subcontinent, Sri Lanka, southern China and mainland Southeast Asia. It can reach up to about 91 cm in the wild, though it usually does not exceed 51 cm in captivity, and is a nocturnal carnivore that swallows prey whole. Globally it is listed Least Concern by the IUCN, though regionally threatened in parts of its range (Wikipedia; FishBase).
Sexing
According to species accounts, mature females are normally plumper than males, but the distinction only becomes apparent at sexual maturity (Wikipedia). No other reliable external cue is documented.
Conditioning
As a large nocturnal carnivore taking small fish, insect larvae, mollusks, crustaceans and annelids (Wikipedia), conditioning means a varied meaty diet over a sand bed in a very large tank. The natural reproductive cycle is tied to the monsoon, so a simulated wet season would be the conditioning endpoint.
Spawning Behavior & Trigger
The species spawns underneath rocky substrates during the monsoon season in nature (Wikipedia). The wet-season flood and associated changes in temperature and water chemistry are the natural trigger; the fish is noted to have relatively low fecundity, which leaves wild stocks vulnerable to overfishing (Wikipedia).
Egg & Fry Care
Eggs are deposited beneath rocky substrate during the monsoon (Wikipedia). Because there are no documented successful captive spawnings, detailed incubation and fry-rearing data for aquaria are not available and are omitted here rather than estimated.
Common Challenges
The decisive obstacle is that captive breeding has not been achieved, compounded by the species' large size, the need for monsoon-scale environmental change and the difficulty of sexing the fish reliably. This is not a realistic home-breeding project.