I had albino barbs...the female got real big..looked fat..but she was carrying eggs.
the male chnged color..fins , nose etc got bright orange..the female had bright orange fins and tail.
the male then chased the female..pushing from behind and under the female ..usually into som plant..they did the is several times..eventually the female drops an egg or two or three..the male fertilized the egg..they did this several times over the span of hours..they also ate the eggs.
typical of barbs...usually considered best to remove the female and male to a spawn tank..with course gravel and marbles..the eggs can then fall between the gravel and marbles..the [arents can't eat as many this way..then remove the parents after the spawn.