Select options Borneo Python Eel (Mastacembelus cf. circumcinctus) $119.99 An uncommon and beautifully marked freshwater eel from the acidic freshwater swamps of Borneo, the Python Eel is a well-camouflaged ambush predator in its natural habitat. In the aquarium, they are hardy but can be shy at first – be sure to provide plenty of cover. Although recently imported fish can be finicky eaters, they will usually learn to accept a variety of frozen foods. Like most freshwater eels, these fish should be kept in tightly covered aquariums as they will utilize even small openings to escape.