Kill it with fire!
They will compete with difficult to keep, beautiful, fromia and linkia stars.
They also have a taste for zoas. Possibly a taste for coraline algae.
There are multiple varieties and they all look alike. Supposedly some are harmless and some are a terror.
6 years ago we intentionally added a few white ones from the LFS and I thought they were really cute.
Have removed over 500 in the past several years and the majority of them are now black (supposedly the bad ones).
In my mind there is no difference. They all need to die.
Begun irradication 2 years ago.
1st month 200
2nd month 100
Rest of year 200.
Since then 100.
They are the gift that keeps on giving.