Royals are hard to sex.for Royals you can't tell by their odontnodes relying on these is not a foolproof method. To add to this if they are young you can't even sex them at all. Generally though the odontnodes of the male are bigger on males smaller on females but then again I'm not 100% that this method works. Let's hope an expert chimes in ((im no plec expert))but if they are still young I don't think they are sexable. I think odontnodes are more of a sign of maturity rather than a viable way to sex them. You can try to look at their vents males have more pointy vents as far as I understand.
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