Lyretail Anthias question

[AC-WEB]

I have a an adult male/female duo of lyretail anthias in my 100g tank. They had been doing well in my 100g tank and have had them for about six months. I heard that anthias do well in a harem, so I added two small females. One week in after adding them, the large female just hides in the rocks and only comes out to eat. Very skiddish. The two small females are happily swimming in the open, but on opposite sides of the tank. The male has not changed and swims wherever he wants, and I have not seen aggression from him on the other female anthias. My questions are the following:

I thought these were schooling fishes, but dont see any schooling behavior. Why?

Why would the large female be hiding in the rocks and look skiddish after adding the two small female anthias?

[MIKE NY]

Most anthias are a shoaling fish not schooling there is a difference...the main difference is a schooling fish will move in the same direction together...both behaviors are a social order and or a defense mechanism seen in the wild. Many species of fish don't do it in our tanks once they realize there isn't a danger and because are tanks are small compared to the wild so they can still see each other....some species of Cardinals will continue to school in our tanks regardless..as for the larger female hidding it be can contributed to many factors including the addition of other females...as long as she is still eating and not being harrassed she probably will come out again..

[AC-WEB]

Thanks for the info, Mike. I will see how things progress.