Zig-zag eel

Mastacembelus armatus are bottom dwellers and occasional substrate diggers[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 2½ 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]

Although zig-zag eels are often combined with medium to large-sized gouramis, knifefish, danios, loaches, Loricariids, eartheaters, acaras, Cichlasomines and Asian catfishes 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]

Being nocturnal carnivores, zig-zag eels forage on benthic insect larvae, earthworms, blackworms and some submerged plant material. In an aquarium setting, they require live foods in their diet such as live fish, tubifex worms, brine shrimps, mosquito larvae, frozen bloodworms, cyclops, krill and ocean plankton.[6][2][7]

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]