Lupus and furcatus are rare-to-non-existent in the trade. Punctatus is overwhelmingly everywhere, being #1 farmed fish in the US. It looks like a channel to me too but channels have a deep fork in their tails at all ages - http://www.planetcatfish.com/common/species.php?species_id=6
The tail could have been "trimmed" by tank mates, etc. I struggle to imagine it is one of the bullheads. The only one with a somewhat forked tail is http://www.planetcatfish.com/common/species.php?species_id=263 Ameiurus catus, North American White Catfish.
ID section: "Sometimes confused with the Channel catfish, Ictalurus punctatus. The white catfish has 22-24 anal rays while the channel cat has 25-28. The white catfish is sort of on the cusp, showing characteristics of both Ictalurus and Ameiurus."
As for the spots on the punctatus, I'm not sure they all have them at the baby-juvi ages. I tend to think they usually do, perhaps not necessarily always.
