Clam on hammer?

[.-=Jord=-.]

One of my frags of hammer isn't opening fully. I noticed two clam like structures around its base. If you look really close it seems to open and close. Is this a pest, disease or just the hammer splitting? Should I try to remove them? This is one of them. Also the hammer is dropping some of its heads.

 

[Diesel]

Ugh!
https://www.reef2reef.com/threads/hammer-pest.321408/#post-3977961

 

[.-=Jord=-.]

Ugh!
https://www.reef2reef.com/threads/hammer-pest.321408/#post-3977961

Thank you. I was hoping it wasn't bad.