Can 12 Chromis be introduced at the same time into a 190g?

[reefwithareefer]

Originally Posted by gobytron

meaning one became dominant, then killed the others, and then turned on himself.

So I know that there is a strong chance that one can become dominant and kill off others. But are you joking when saying it can turn on himself because of a reflection? Does this happen to many other species as well?