As far as I know you can sex them when they are mature and the males get bristles on their head and the edge of the pectoral fins. I don't know if you can sex them from underneath.
Yep, I can't tell either yet. What size is it? I don't see any bristles around the face & nose underside but it may be too small. Females can have some bristles but not like males get along their foreheads.
Yep, I can't tell either yet. What size is it? I don't see any bristles around the face & nose underside but it may be too small. Females can have some bristles but not like males get along their foreheads. About 1.5 inches
That seems too small to tell yet. Try looking at its "top side" as it grows up. Not always easy, mine are either on the glass or hiding but often on the substrate when waiting for food.