This particular species, classified as L204, shows a remarkable similarity with Francesco's unclassified wild caught Panaque sp. The fish in the pictures above was collected in Peru which supports the view that it could well be the same fish. At this point the confusion starts.
According to Francesco's "Fast fact sheet" this species is an unknown Panaque. According to Aqualog (All L-numbers) the fish is also classified as Panaque sp. "Peru" with a supposedly total adult length of 15-20 cm. The specimen in the photo is already 12 cm in length. According to Planet Catfish ( www.planetcatfish.com - data submitted by Yann Fulliquet) this fish is a Panaqolus sp. Unfortunately, there aren't any pictures on this site, which would make things easier. The general description of the animal matches what I see in my tank but so does Francesco's description. It is also reported to be a wood eating animal (which it is), but this is true for the Panaque species, too. The final sizes reported from all three sources also match. For a review of the information listed in Planet catfish you may take a look at http://www.planetcatfish.com/core/admin/index.php
As Francesco stated in his article "The Royal Pleco group" there is a lot of work to be done as far as the correct classification of the species belonging to this genus is concerned.