So I have had asterina starfish in my 90 gallon for about 2 years with no issues but my wife's 60 gallon also has them now and she had lost 3 colonies of zoas. I have dipped these colonies several times finding no pests and I am always finding the asterina starfish on them. other colonies in the 60 gallon tank the starfish won't or haven't touched and they are thriving. They seem to target the bright red and pink zoas. this has been going on for a few months now and I am 99% certain it is the asterina starfish. I know I will never be able to eradicate them completely in this tank but when I put up my new tank I will make sure these guys don't find their way in.