at what age can i see the difference????

[xander]

Who can help me,

My name is Xander de Wilde and i'm from the Netherlands. For a long time i'm looking for an answer to a question i have. For that answer i've read books and i've searched the internet, but with no result.
I've got two A. cacatoides in my tank and they look both the same. I bought them as an male and a female.
In the period i have them they both have turned yellow, buth they also
showed spawning behaviour.
There is no difference in dorsal, caudale fin size.
Tonight is saw them go together in side the breedingpot. after a while one,
the smaller one, came out. I saw that the caudale fin was damaged. The other one stayed in the breedingpot and started to defending it. I also saw that the color was changed from yellow too a 'black' dark brown coulor.

My question is: How old must a A. cacatoides fry be to tell the difference
between an male and a female???

 

[Z Man]

Within a few months you should be able to tell the difference. Just check the ventral fins. The leading edge of a female will be solid black and the fin will be short. The male will have little or no black edging and the fin will have a long pointed extension.