Descrizione originale come 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); p 499 (crc00057)
Conservazione: Rheoheros coeruleus non inserita dalle organizzazioni internazionali di salvaguardia delle specie a rischio nella lista rossa. The Tulija river is found in an area where the pressure for deforestation has been large in past decades during which large extensions of rain forest have been destroyed. Nonetheless the ares is also subject of several conservation efforts partly due to it highly touristic nature. Aquatic ecosystems still remains 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.