So I have a Venustus and Z-rock about 4" long now. I see a very very slight hint of blue on the venustus gills and the scales of the z-rock. Does this mean they are males? Can a female have a hint of blue on any part of their body?
Zrock should be way more colored up at 4inches than what you are describing for a male. My only other thought would be possibly bigger more dominant in tank males keeping his colors down (if it is in fact a male)? Agreed with the venustus 3 inches is honestly too small to tell sex unless you're a pro at venting and still at 3" it's probably tough to tell. Probably didn't help much but that's my 2 cents lol