Not sure about the left. Most likely a premature male
Looking back, I now agree the left is more likely a male. I apologise to the OP for the inaccurate info. I must have not had my morning coffee before posting lol.I also think you have a possible male on the left. Another tell is the central fin, at least much of the time. They look a little stressed
Bit annoying as went out and bought two more (one of which I am 99% sure is male) but it's all good. Will just see how they all get on.Looking back, I now agree the left is more likely a male. I apologise to the OP for the inaccurate info. I must have not had my morning coffee before posting lol.
The analfin is more square (male indication), but the big giveaway I missed before, is the face. The female has a much broader, rounder face/head, the male's is a bit less bulky, especially below the bottom lip. This is another visual way to sex bolivians. I agree they do both look slightly stressed.
I think was looking at their bellies to sex them at first (I find males are usually slightly slimmer, especially once sexually mature), as they both are very plump, which indicates female, however I think they are just very well fed.
I would still vent them personally, to be sure, as bolivians are notorious for being able to indicate traits of both sexes