Mastacembelus is a genus of many species of spiny eel fish from the family Mastacembelidae. They are native to freshwater habitats in Africa and Asia. Some species are relatively common in the aquarium trade such as the fire eel (M. erythrotaenia) and zig-zag eel, (M. armatus) (also called the tire track eel although M. favus is properly given the common name of tire track eel).