I've kept OH tapajos both ways, including as a single breeding pair in a SA community with good success. Reminds me of discus, in the sense they prefer to be in a group growing up, but can be perfectly content as a pair as adults (with dithers or other species in the tank, don't know about keeping them alone). IME both male and female are equally zealous about cleaning a spawning site. I'd say it likely varies by individual pair. From what I've seen other preferences can vary somewhat by individual pair. I've also seen the courting and site prep process vary with different spawns, depending on circumstances in the tank, including the spot they pick, how much competition for territory there is in the tank, or what other fish are present.
What I found cool if you get to see it is mine sometimes trade off holding fry-- sometimes one eats while the other holds, for example.
If you're observant and have had both types of fish, their pre-spawn and courting behavior is very reminiscent of African aulonocara, not necessarily the same psycho aggression on the part of the male, but the circling, flaring, displaying, etc. is similar, as you can somewhat see it in the video posted above. I've spent years with both types of fish and the difference in body language between continents that some people make a big thing out of is somewhat overstated. The difference is more between genus, body plan, species, etc. than strictly continental. For example, cyphotilapia 'body language' is different from haps/peacocks, in some respects very different... or, as another example, the pairing up behavior I've seen with (suriname type) geos has been different from what I've seen with guianacara.
He's the current tank boss. Since I switched to dark substrate about a month ago, he's been full of himself, pumping up and down the tank with full finnage on display. When those 2 in the video get too romantic, he always decides to run in and break it up ha
