Doing some research on pseudoplatystoma, and came across this document.
PSEUDOPLATYSTOMA GARCIAMARQUEZI, A NEW SPECIES OF
GIANT TIGER CATFISH (SILURIFORMES, PIMELODIDAE) FROM
THE MAGDALENA BASIN, COLOMBIA: A SPECIES THREATENED
WITH EXTINCTION
Found here:
http://www.ibcperu.org/doc/isis/7162.pdf
Based on evidence presented within that would make this the 9th recognized species in the genus. It is also evident from reading it that it has many of the same authors and ichthyologists as the document that set up the 8 species described in the beginning of this thread. Many of the same methods were used to describe this species, and there is speculation within that it could be the largest of all the Pseudoplatystoma species. Also would be considered an endangered species.