Original description as Haplochromis orthostoma:
- Regan, Charles Tate. 1922. "The Cichlid Fishes of Lake Victoria". Proceedings of the Zoological Society of London. v. 1: pp. 157-191 (crc00355)
Conservation: Pyxichromis orthostoma is evaluated by the international union for the conservation of nature in the iucn red list of threatened species as (VU) vulnerable (1996).