Dandelion fluff on hermit's shell?

[MoJal]

What is this riding on my hermit's shell? It looks like a dandelion fluff, but seems to be moving up and down rhythmically (as opposed to with the current). Friend or foe? 

[Smurf]

Thats an awesome hitch hiker! 

 

Looks like a tiny baby feather duster. Harmless filter feed and harmless to your little cute crabby.

[MainelyReefer]

I vote hydroids, these can be inert or a PITA

[Tamberav]

My vote goes to it being a barnacle by your description (rythmic movement). They are good filter feeders.

[mcarroll]

Is it growing out of a little "volcano" or is it growing on a stalk?

 

volcano = barnacle

stalk = pest (IMO)

 

 

And just BTW those stripped "common hermits" can get huge.

[MoJal]

13 hours ago, mcarroll said:

Is it growing out of a little "volcano" or is it growing on a stalk?

 

volcano = barnacle

stalk = pest (IMO)

 

 

And just BTW those stripped "common hermits" can get huge.

He's in a volcano.  And yes, I've been considering rehoming him... right now he's not big, but dont want him to cause trouble. 🤔

 

On 2/15/2020 at 9:27 AM, Tamberav said:

My vote goes to it being a barnacle by your description (rythmic movement). They are good filter feeders.

Bingo! It's a barnacle! Found some pics that match perfectly. Thanks for pointing me in the right direction!

[mcarroll]

I'm not sure if he's removable, but I also don't know if it'll survive long.

 

You hear lots of reports of these showing up as hitchhikers....but you don't see lots of photos of them later on......or photos of tanks where barnacles have taken over.

 

Either way I wouldn't see him as a worry.