Interesting, Lophiosilurus Fowleri (formerly Cephalosilurus Fowleri) had been banned for export by Brazil since 2012 I believe but I did read recently that their export is now permitted. Obviously the first thing to know is if the fish @ Predatory Fins was imported from Brazil as this species is only endemic to one river there, The Rio Sao Francisco, same river as L. Alexandri. Lophiosilurus Apurensis are only found in Venezuela and Colombia. From the photo's shown on P. F.'s website, the one showing the fish in hand, (easily a 6" fish) could be L, Fowleri, the other photo with the blue gravel background was taken from the PlanetCatfish website. The stated size of the fish for sale is 3". The two species are very similar in appearance as juveniles. When comparing the two from a profile, Fowleri's have a flatter head than Apurensis. The more obvious difference is the belly markings of lack thereof, in that the Fowleri will have a clear pale belly whereas the belly of Apurensis will be heavily marked/spotted by comparison. Look in the Cat-eLog on PlanetCatfish for both species, some photos found there are of my former Fowleri and Apurensis. I recently lost my L. Fowleri after 17 years and would easily have another, an all time favorite. Both have similar behaviors but Fowleri tend to be less aggressive and only grow to about 18" where Apurenis are more aggressive and will grow to 28". I think, not sure, that the owner of PredatoryFins is a friend of Viktor's, perhaps he has talked to him about these? Perhaps a call to the vendor might reveal information as to the origin of the fish and maybe a photo of the underside of the fish which would be very helpful. All this being said, he may indeed have real L. Fowleri's and if so, great! At the asking price stated it would be a good deal in todays market, even if it turned out to be L. Apurensis, still a good price for one of them too...