In an earlier incarnation I was actually an ichtyologist, but haven't stayed current. However, as of about ten years ago, Mudcats and Bullheads were all taxonomically placed in the same family (Ictaluridae) and genus (Ictalurus), but in different sub-genera. As I recall, there were then recognized four species in the subgenus containing the "mudcat" (i.e.; the larger species), including the channel cat, the blue cat, the brown cat, and the spotted cay. You have to be careful about using the common names, because thay are frequently applied to several distinct species. I recall that the "blue cat" was the one most commonly called the "mudcat", and specimens of 150-200 pounds and 6 feet in length were reported in the early days from the Mississippi River. Mostly due to the intense fishery pressure, such large specimens are no longer seen. These species were originally fairly wide-spread east of the rockies. Bullheads, by contrast, were smaller (rarely over a foot in length and a couple of pounds weight))and originally confined to areas east of the Missippii River. Both groups have since been widely introduced in areas far beyond their original distributions. So, as to the original question, "are mudcats and bullheads the same?", the answer is no, but they are close cousins.