Regular C. arcuatus is from the Loreto area in Peru and a large area reaching into Ecuador as well. According to Fuller & Evers, the Super Arcuatus comes from the Purus river, which is further south in the western part of Brazil. I will add this to the occurrence data for Super Arcuatus.
The much larger similar looking species known as 'Super arcuatus' have the CW- number CW036 and have been reported as growing in excess of 16 cm SL. However as far as I am aware no specimens of these proportions have entered the aquarium hobby.