I have a pair of Orinoco severus. They are slightly different from the Atabapos. My pair is relatively small but they've already been spawning for a while. I really like them a lot.
^ Yes, it's a rotkeil. It has 8 vertical bars rather than the common 9 on efasciatus, and also is beginning to show the red behind the gill and on the chest. This should continue to develop as it ages.