Original description as Theraps coeruleus:
- Stawikowski, Rainer & U. Werner. 1987. "Neue erkenntnisse über die buntbarsche um Theraps lentiginosus mit der beschreibung von Theraps coeruleus spec. nov.". Die Aquarien- und Terrarien-Zeitschrift (DATZ). 40(11):499 (ffm00057)
Conservation: Rheoheros coeruleus is evaluated by the international union for the conservation of nature in the iucn red list of threatened species as (DD) data deficient (2018). The Tulija river is found in an area where the pressure for deforestation has been large in past decades during which large extensions of rainforest have been destroyed. Nonetheless, the area is also the subject of several conservation efforts partly due to its highly touristic nature. Aquatic ecosystems remain in very good shape. The imminent invasion of a Loricariid species which has decimated other rivers in the Grijalva-Usumacinta is likely to occur and affect the environment and fish populations in the area but in the end a balance of the biomass should be reached and as in other rivers of the system the species populations will likely partially recover.