FYI about the barbs:
"Adults of Puntius tambraparniei are distinguished from P. filamentosus , P. singhala and P. assimilis by having prominent black markings on body anterior to the anal-fin origin. They differ from P. exclamatio by lacking a horizontally-elongate, tear-shaped black blotch above the anal fin. Puntius tambraparniei differs from P. srilankensis by having lower lip entire (vs. medially absent). It differs from P. arulius by having branched dorsal rays elongated into filaments in adult males (vs. dorsal fin concave and emarginate) and by having a pair of maxillary barbels 2.4-4.7% of SL (vs. <0.5%)."
It therefore seems that the fish sold for decades as P. arulius is in fact Puntius tambraparniei, and the recently imported Puntius tambraparniei are actually the true P. arulius ! P. arulius can thus be considered quite a rare species in the hobby, with all those fish on sale as "Arulius barb" likely to be Puntius tambraparniei.