Mastacembelus armatus is a large elongated fish that has a snake-like body without pelvic fins. Its anal and dorsal fins are elongated and are connected to the caudal fin. The dorsal fin is preceded by numerous spines.[7] The back is dark beige in color while the head is silver-beige. The body's color is dull brown and the belly is a lighter shade of brown. The body may also be marked with brown circularpatterns. The body also have one to three darker longitudinal zigzag lines that connect to form a distinct reticulated pattern that is restricted to the dorsal two-thirds of the body. The eyes have brown stripes running laterally through them.[6][2]
Mastacembelus armatus can reach up to 36" (91 cm) in its natural habitat but does not usually exceed 20" (51 cm) in captivity.[6][2]
Despite its eel-like appearance, Mastacembelus armatus is not considered a true eel.[7]
Mastacembelus armatus are bottom dwellers and occasional substratediggers[7] and burrowers. Those that are 6" (15 cm) long do well in tanks measuring 36" (91 cm) with a capacity of 35 gallons (132 liters). However, larger M. armatus necessitate aquariums measuring at least 48" (122 cm) with 55 gallons (209 liters) capacity.
Zig-zag eels do well in freshwater or slightly brackish aquatic environments (produced by adding two teaspoons of sea salt (not iodated) per 21⁄2 gallons of water)[7] with 6 to 25 dH water hardness, with pH readings ranging from 6 to 8, and temperatures that are maintained between 73 and 81 °F (23 to 27 °C).[6][2]
M. armatus tend to uproot plants and disturb decorations.[7]
Compatibility
Although zig-zag eels are often combined with medium to large-sized gouramis, knifefish, danios, loaches, Loricariids, eartheaters, acaras, Cichlasomines and Asiancatfishes in a community fish aquarium, they are not normally mixed with small-sized fish, because tire track eels are observed to prey upon smaller fish. Mixing them with fish belonging to the same species is also not recommended.[6][2] This is because they are aggressive to members of the same fish family but peaceful to other fish species with similar care level requirements, size and temperament.[7][8]
Male and female zig-zag eels are only distinguishable when mature. Females are normally plumper than males. Although their fecundity in the wild is high, there are no known successful breeding programs in captivity.[6][2]
