Taeniopareius, you are right, some others too, like G. australis, G. meridionalis, A. facetus, C. dimerus, etc, etc. All of them have a wide distribution. In the case of a G.fortaleza, it is an endemic species of fortaleza stream and to this day was not found in other sections of the same basin, so it is inprobable that it be the same species.
The size of G. fortaleza is similar than G. australis.
Pipo, you are probably right, to be sure i would like to see any picture not burned by de flash