What is growing over this Hermit Crab shell?

[road102]

Hello

This is some sort of gray layer growing on top of Coraline, if you look closer you will see a tiny little antenna/stick (seems to be green)..

Any ideas?

Thanks !!

 

[jabberwock]

Looks like it came out of the play dough fun factory. Following

 

[landlubber]

my non-professional guess is possibly another species of coralline algae. pretty cool though.

 

[bnord]

what happens when you touch it with something sharp?

 

[blaxsun]

You should definitely name this crab "Barney".

 

[road102]

what happens when you touch it with something sharp?

Nothing, this stuff is hard and grows faster than coraline…

 

[road102]

You should definitely name this crab "Barney".

Lol

 

[bnord]

Nothing, this stuff is hard and grows faster than coraline…

never seen anything just like this, must be a bland Coraline

 

[WheatToast]

I do recall reading about some encrusting red algae with tan coloration, but I forgot it’s name.
The tentacles might also be indicative of bryozoans or something imbedded in the algae, like barnacles.