hmmm, I just double-checked ...I don't see any links I missed....a link to IGFA world records?Hey, Frank! Do you make it a point not to look at the database snippet I've attached several posts up?Teasing you but you set yourself up. It lists the catus and a couple of bullheads with max sizes from FishBase and Fishing World Records.
Rob's done a super job explaining why it was reclassified but to understand it more, you can read the revision that had done exactly this - moving catus from Ictaluriids into Ameiurus. Besides size and biology, it's hard to argue with a proper DNA study.