We are seeing the first black tail bar develop in our juvenile personatus. Some fish have already left the nest to other homes and I have heard of at least one of those that is also developing it's black bar.
Here's a link to a video showing the black bar developing on a 189 day old G. personatus. The video was taken several days ago and the black bar started coming in as a light grey bar two weeks ago. https://www.youtube.com/watch?v=e6QAXK1n9l4
We also have a tailless fish who is now known as "Hula"