Original reference as Placidochromis sp. 'longimanus thumbi':
- Konings, Ad. 2007. "Malawi cichlids in their natural habitat (4th edition)". Cichlid Press. 424 (crc01558)
Conservation: Placidochromis sp. 'longimanus thumbi' is not evaluated by the international union for the conservation of nature in the iucn red list of threatened species.