Iodotropheus is a small genus of cichlids endemic to Lake Malawi in east Africa. The genus is distinguished from other genera of mbuna by the upper lip which is usually connected medially to the skin of the snout by a frenum; by its small, terminal mouth; by the outer teeth of both jaws, which are unequally bicuspid and loosely spaced, the tooth shafts inclined slightly toward the jaw symphysis; by the anterior teeth of the upper jaw being much longer and more robust than the lateral and posterior teeth. The rusty cichlid or lavender mbuna, Iodotropheus sprengerae is the most commonly encountered member of the genus in the aquarium trade.