This video shows the genital papilla in both sexes of large specimens of tilapia. The close view shows that in males the genital papilla has only one opening (the urinary pore of the ureter) through which both milt and urine pass while in females the eggs exit through a separate oviduct and only urine passes through the urinary pore. We understand that it is much easier to sex large specimens like the ones shown in the video, but for people who are not familiar with tilapia, it may be useful to clearly show the difference before applying it to much smaller sizes.
In general, during the breeding season, the genital papillae of both sexually mature fish become enlarged and turn easily distinguishable.
The sexing of advance fingerlings and/or tilapia juveniles might require some training and personal skills in order to carry out the sexing process with highest rate of accuracy.