[Peter Finke]

Some questions and remarks:
1. Who or what is “LFS”?
2. It is very unusual that a blue band in the unpaired fins disappears altogether when displaying. Is this observation allright? I doubt it because you describe two males in an aggressive mood, not courtship.
3. This is the next point: Your fish show an aggressive colouring which is different from that of courtship. P. spec. Ampah show this strong brownish-blackish lines in the caudal, dorsal and the anal fins in aggressive situations, males and females. The latter in dorsal and anal only. But all Ampah lack blue bands at all!
4. Only a few of the Ampah-males show filaments, and they are mostly short. The caudals of some appear nearly (but not fully) rounded. At least in the males those blackish streaks must be visible.
5. P. allani is quite improbable, one could exclude that. This species is isolatedly living in Sarawak, and there is no one commercially catching Paros. Your description don’t fit to that species, either. It was never imported commercially so far. Besides, it does not show “brown fins”. The dorsal shows much red (and often a big black rounded spot), the anal much blue, and both have broad black lines at the edges.
6. Let us wait for good photos, but it could well be the case that you observed two aggressive aff. bintan-males.
7. But tell us how the dealer of the fish houses them: Are there several species obviously mixed in one tank, so that it would be easy to catch different species out? (Of course, mostly the mixing is not obvious, but factually that is possible). Are there spec. Ampah in that tank, too? Are there other companion-fish? Are there possibilities to hide?