The Tire Track Eel (Mastacembelus armatus)

There are many “eels” available to the home aquarist, though, strangely enough, most of them are actually quite distantly related to the true eels, known scientifically as the Order Anguilliformes. Take, for instance, the Tire Track Eel (Mastacembelus armatus), which is a very distantly related creature that only happens to share a similarly eel-like body. One of the best ways to tell a true eel (such as a moray) apart from this group is to look at the dorsal fin, which is full of sharp spines in Mastacembelus. This gives them one of their other common name, the Spiny Eels.

The Tire Track Eel is one of the most abundant members of its genus in the aquarium trade, and the species has a particularly wide distribution across the warmer parts of continental Asia. It occurs nearly everywhere and in nearly every kind of habitat, from upland streams to lowland wetlands and even occasionally in slightly brackish estuaries. Since it’s able to reach a hefty size of nearly three feet in length, this fish is regularly exploited in its its native lands for human consumption.

In an aquarium, this is a relatively peaceful addition that will only pose a danger to fish small enough to be consumed whole, particularly those with an elongate body. Beware, the mouth is definitely a bit larger than it seems. Larger cichlids, catfishes, and loaches make for good tankmates, as do some of the bigger barbs and tetras. It’s generally best to keep just a single Mastacembelus per tank, as they will, especially as adults, fight amongst themselves; however, in a large enough aquarium, a moderately sized group is a possibility.

Remember to provide adequate hiding places in the tank’s decorations for the entire body of the eel to be concealed. Rocks and driftwood can accomplish this, as can pieces of PVC pipe. A mix of meaty foods or sinking pellets makes for an ideal diet, and, for this nocturnal beast, it can be helpful to feed after the tank lights have been turned off. These gentle giants are capable of living for many years, if not decades, and definitely make for a fascinating and unique addition.