Janus is a genus of cichlid fishes native to Africa. It contains six species, all of which are endemic to Lake Tanganyika in East Africa. The genus is named after the two-faced Roman god Janus.
The Janus cichlids are small to medium-sized fishes that reach a maximum length of 15 cm (6 in). They are characterized by their elongated bodies and pointed snouts. The eyes are located at the top of the head, giving the fish excellent binocular vision. All species have three pairs of barbels around the mouth, which they use to locate food in murky water. The body is covered with large, thick scales.
The Janus cichlids are predators that feed on smaller fishes and invertebrates. They are territorial and aggressive towards other fish, but peaceful towards members of their own species. Males and females often form monogamous pairs and care for their young jointly. Spawning takes place in caves or among rocks, where the female lays up to 500 eggs. The male then guards the eggs until they hatch after about two weeks.
The Janus cichlids are popular aquarium fish due to their beautiful coloration and interesting behavior. They are relatively easy to care for, but require a large tank with plenty of hiding places because of their aggressive nature.