What are these coral critters?

[Stringztoo1]

I just got back from Tampa Bay Saltwater, (great rock), and purchased some live rock there. Alot of it had coral-like attatchments, also had alot of life on it. Anyway, when I got it home and put the rock in the tank, I saw alot of movement.

Every piece of rock I bought had these little barnacle type things on them. To explain it visually, it looked like a little rock volcano, with a hole at the tip. When the rocks went in the tank I saw all these barnacle things had something in each of them.

These little creatures sweep their finger-type things out in the water and just as soon, pull them back in. Like it's sweeping the water to eat. Even my hermit crab has coraline algae growing on it's shell with two tiny barnacles as well, and they're on his shell too! What are they? They look like teeny tiny itsy bitsy feathers dusters in a barnacle cucking in and out. Are they good for the tank? Any info would be great.


(p.s.) Tampa Bay Saltwater has great live rock, lotsa stuff on it. Not very brancy like Tonga or cavernous like Figi, but good layering rock anyhow with many live critters on and in it.

 

[Jrsydevi1]

Hmm..

Gonna go out on a limb here...

They're... barnacles?

 

[Tide man]

Almost absolutly sure there barnacles. They are feeding when they sweep there "hand" out like that. They are filter feeders and mainly feed on types of zooplankton like larval pods and such I think. Hope that helps.

Later

 

[LINK]

I got 2 Barnacles on my Galaxia. They are right in between the Polyps on the Galaxia, and their little White "Hands" sift the water constantly. They can seemingly twist 360 degrees inside their shells with their hands out. Very Cool