Hello Mach Easy way to tell them apart , even at a 1/2 inch in size..... females have vertical bars in the caudal fin.... males dont...... pretty simple. These vertical black bars are very pronounced, even at a small size.... Hope this helps you out. I have 2 young females ...... if anyone has a male or needs 2 girls ..... let me know... thanks John ------------------------------------------------------------------------- This is the apistogramma mailing list, apisto@listbox.com. For instructions on how to subscribe or unsubscribe or get help, email apisto-request@listbox.com.