Pest ID help.

[AdamKo]

Please help id these creatures.
I think that's hydroids,but I am not sure.
I used to think that healthy coral will grow dead tissue but it is getting worse. I need to cut the coral.
TIA

 

[AdamKo]

Any ideas?

 

[SamMule]

Coral boring spionid worms maybe?

 

[AdamKo]

Thx a lot, I think this is it. I found this on my one acro also. Luckily very close to the base.

 

[Crabs McJones]

Coral boring spionid worms maybe?

my guess as well

 

[RudeDawg]

Thx a lot, I think this is it. I found this on my one acro also. Luckily very close to the base.

Any update?
Were you able to remove the infected acro before the worms spread to your rock?