What are these???

Ronster007

Membership Expired
Thanks to my Copperbanded Butterfly, all my Aptasia is gone! :D

However, these (pic) have popped up and the butterfly won't have anything to do with them. Any ideas on what they are? Harmful?
 
I believe those are the dreaded Mojano nems. You really need to take care of them or they will spread. Worse than aptasia.
 
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