Young Bettas, sibling Bettas can often be kept in groups, even unrelated adult male B splendens can be maintained in "groups" IF care is taken with selecting the individuals & tank set up (though also expect some flaring & likely fin damage)
Unfortunately with the advent of "dragonscale" or "metallic" B splendens (likely introduced through hybrid crosses though this is unclear), the presence/absence of "iridescent scales on the gill cover" is no longer a defining indication of B splendens vs non-B splendens
While show quality "dragonscale" is obvious, this trait shows a broad range of phenotype (rather like "halfmoon" & "rose" tail expression) & has "contaminated" many lines.
if it has a white dot then it's a female holding eggs which they get constantly. I'd never buy from pets at home in the future. I used to when I first started out and got a male betta sold as a female......
Males can also show a "white dot" & females can lack a "white dot", so this is not definitive of female B splendens
Young Bettas can be difficult to distinguish sex, especially if you aren't familiar with the line ... there is also trade in young females Bettas (much lower value) being sold as (fancy) juvenile male Bettas, especially plakat lines
I don't support Big Box aquarium shops but I'd not hold (likely inadvertent) Betta sex confusions against them
😉
Im going to my lfs over the weekend and the owners a betta collector so maybe he'll know more.
& please support them as well
🙂