Rhinodoras armbrusteri is a species of thorny catfish known from the Takutu River and Ireng Rivers that drains into the upper Rio Branco in Guyana and Roraima State, Brazil; it is also known from the Rupununi River in the Essequibo River basin in southwestern Guyana. This species grows to a length of SL. References Doradidae Vertebrates of Guyana Fish of Brazil Fish of South America Fish described in 2008