Marc, you wrote they were fond with the Beaufortia, I hope my English is good enough to understand that it really means they did not harm them?
no, as in fond of "moveable snacks"....
I had mine much longer ago, but small Corydoras, Characins and livebearers learned fairly quickly to get out of the way.....
I think it's transparant coloration is a weird way of camouflage; add that to theit agility and you see that they can "creep up to" other fish fairly quick.
I think Tridensimilis is not an obligate parasite, like Vandellia and the like, but it sure makes use of oppertunities when those arise.
I once had an Ochmacanthus and he was much worse, but then; that's a much more "evil-looking" bugger, and he didn't hesitate to attack almost anything.
but best keep them apart; they have a large "overbite", and it's full of sandpaperlike teeth....perfectly shaped for rasping slime and other parts off other fish.
you might want to try it out, but....