Hermit crab, sand sifting conch, corralline shell questions

[CoralCastle]

Just got these from LFS and though it was normal but starting to wonder. What is that growing on the shells of the hermits? And the sand sifting conch?

Also, I got this shell with corralline growing on it and wanted to aeed the dry rock with it but noticed these yellow worm-like things on the back of the shell? Any thoughts on that/those?

They said it has sponge growing on the inside and read everywhere that all sponges are fine...? Is that correct?

I'm new to saltwater stuff as you can tell

 

[Rtaylor]

It all looks normal and nothing to worry about. The purple is coralline algae.

 

[CoralCastle]

It all looks normal and nothing to worry about. The purple is coralline algae.

I got it Friday, been sitting in a jar with the LFS water. Had to ask about it and wait and now that I know it's fine I am stuck up north and won't be back until tomorrow so it'll have been sitting there for a while. Will the corralline be alive? Praying

 

[Rtaylor]

The coralline will be fine.