Possibly a what?

So we got a new sun coral for our tank today, and on the bottom of it we noticed 3 shelled like critters and trying to figure out what they are.

all three are a shelled creature with two more pieces of shell that open

they have "fingers" that pop out and swipe at the water like they're trying to grab food

Tried to get some good pics, but the crabs were making it impossible. LOL!



In the middle at the bottom of the sun coral is the bigger one, and there's two smaller ones on the side.

Thanks for any help!

 

If they have like a circular web then they are a crab but i cant think of the name off the top of my head. Almost like a pom pom crab without the pom poms.

 

They sound like barnacles.

 

Hmmmm, I think you're right. They certainly look like goose barnacles. Thanks!

 

Yeap! Barnacles for sure, but that's not the reason I posted, you already know that love the sun coral, my most favorite, I will get one some day.