Julidochromis Marlieri has a fairly widespread distribution throughout Lake Tanganyika, where it is found amongst the sediment-rich rocky habitat in moderately deep water. Here, their territories tend to be centred around cracks or fissures in the rocks and rubble. The natural diet consists primarily of small crustaceans, insect larvae, and molluscs picked from the algae-encrusted substrate, and occasionally, drifting plankton.