I'd say that %99 or more of the cats that everyone calls perruno are actually Leiarius longibarbus(formerly marmoratus). That's what they have been sold as since they were first imported and because the importers didn't properly check anatomical features to ensure the species people have been confused every since. Leiarus longibarbus has 12-13 soft dorsal fin rays, and perrunicthys perruno has 9-11 soft dorsal fin rays. longibarbus gets slightly larger, but not by much. I think in the future we may see these species combined as there is much confusion, and further genetic testing is combining and seperating catfish species all the time. Just look at all the rearrangement of the pimlodidae family in the past 5 years.