L260 pair, for reference:

[drpleco]

Lots of folks (myself included) have been trying to sex QA's lately, so I figured I'd post a pair from my group for reference. Jools, if you see this and want pics for the catelog, let me know or feel free to take them off this post.

Male is on the left. This particular female is just hyper gravid but the male won't let her into his cave. Hopefully soon...

[Mike_Noren]

Does the "females have unpigmented bellies, males have mottled bellies" rule hold for your fish?

[drpleco]

nope. that's a picture I forgot to take, but I looked while I had them out. The male has a fully marbled belly and the female is marbled across the ventral area. She has a clear "chest", but that's about it. Definitely not un-marbled as she "should" be. good question!

[LitosCBR]

Nice contribution. It seems quite clear that there are a couple, do they have the same age?
Good luck with them.

Concerning the bellies pigmentation (ok, mines are L411), I think it gets marbled with age. When I look to the first pictures I took, I saw it more white than today. Maybe males are much more marbled from the beginning, but an old marbled and hairy female could be similar to a dominated male (if you do not have a male of the same age to compare). What do you think about?

Carlos

[drpleco]

Regarding the belly pigmentation, I don't know if they get more with age, but my fish have all had the same areas shaded from day one. I bought them as wild-caughts, though, so I don't know at what point it developed. Both fish were purchased at the same time about a year ago and have each grown about a half inch. They developed the secondary characteristics (odentodes, swollen belly) a few months after I got them. When I bought them there was still a clear different but body/head shape and size was the primary indicator.