sexing juveniles

[matt0129081]

I have 10 cacatuoides juveniles, I think they are 3 months old now, they are around 2cm long. I have a question about sexing them. THe adults are easy to sex, but I am not sure about the juveniles. At what age do they become sexually dimorphic? They all look female, but some features are starting to maybe look male. For example, I can see the begininngs of a lyre tale forming (but adult females also have this slightly) and there are some reticulations forming on the caudal fin and anal fin, but again this is present in some adult females. Is it too early to tell easily or is it likely that all 10 are females?

Thanks
Matt Watson

 

[Mike Wise]

It's probably too early. I would expect that those with markings & extensions on the caudal fin will become males. Only much older females (over 18 months of age) will develop these features.