Possible hydroid or feather duster on hermit’s shell?

[fisherdonk]

My new hermit crab has this hitchhiker on its shell. I’ve noticed that it retracts quickly in response to sudden light change. What should I do?

 

[Sharkbait19]

Closeup under whites would help - but it just looks like a duster from here. If so, harmless.

 

[fisherdonk]

Sorry my camera is horrible. This was actually under whites!

 

[Sharkbait19]

Sorry my camera is horrible. This was actually under whites!

No worries, if you have a flashlight it can help.
If it retracts quickly then it is a duster (I’m 99% sure it is even from the photo though).

 

[fisherdonk]

It definitely retracts quickly. Even when I shine just a flashlight on it.

 

[Sharkbait19]

It definitely retracts quickly. Even when I shine just a flashlight on it.

Definitely a duster. You probably will have a lot more soon.

 

[Tankkeepers]

Duster I can see the fan even in the atinics hopefully you will get more as they help the bio filter if they establish