Unknown small circular critters on live rock - Please Help ID!

[15galreefSD]

Hey Everyone! I just started up a small 15 gal reef tank thats in the process of cycling (About 2 weeks in).  I noticed some little light brown circular critters on the live rock and wanted to make sure they aren't anything i need to worry about.   

 

It's hard to tell in the pictures but they're tiny like 1mm diameter, light brown and theres a ton of them, they appear to be attached to the rock and  have tiny little arms in a ring shape. 

 

Any help IDing these suckers would be much appreciated! 

 

 

 

 

 

[Joevember]

Spirorbid worms?

[RayWhisperer]

Not spiros. These are very interesting. I have a theory, but I'm just not sure, yet. 

 

Let's try something before throwing guesses around. Take some of those pics. Note where they are, and from what angle they were taken from. Give it a day or two, and take another pic as close to the original as possible. See if there is any movement, no matter how minute.

[Joevember]

I thought he was talking about them because of how small they were. Still don't know what the larger one's are. Good idea with the pics, that'll rule out a bunch of things after.

35 minutes ago, RayWhisperer said:

Not spiros. These are very interesting. I have a theory, but I'm just not sure, yet. 

 

Let's try something before throwing guesses around. Take some of those pics. Note where they are, and from what angle they were taken from. Give it a day or two, and take another pic as close to the original as possible. See if there is any movement, no matter how minute.

I thought he was talking about them because of how small they were. Still don't know what the larger one's are. Good idea with the pics, that'll rule out a bunch of things after.

[15galreefSD]

Hey Everyone, I took some pics today and will try to take similar ones in a day or two to track any movement.  From what i can see now they're opening a bit and with their little tendril things sticking out more than before.  They're all the same size (about 1mm diameter, 1mm tall) and are  look like tiny anenomes.  If you look really close theres a little opening/mouth in the middle of them.  My concern is that they're some type of pest like aiptasia that i need to get ahead of, does anyone know what an army of baby aiptasia looks like?

 

Thanks, 

 

-TK

[RayWhisperer]

Ok, they haven't moved. At least the several I compared from the pics from a few days ago. I was thinking fromniferan, but that's out. 

 

They arent aptasia. Nor are they a hydroid or majano. I'm doubtful they are pests. However, that's just a guess by structure. They do look like fungia. And fungia do grow from certain rocks. Not just any rock, but you get the idea. I've seen one or two fungia factories, never dozens like this looks. 

 

So, try googling plate factory, or fungia factory. Dig through those images and see if you can find anything similar to yours. Not numbers, cuz I doubt you'll find any like yours. Most images are going to be bigger than yours, like nickle size. But maybe you can find a pic of a tiny one to compare structures.

[RayWhisperer]

I couldn't find a picture. However, I did find a post of something similar to yours. 

 

Check this thread. The third post by a member named Reefmonster. He/she claims his/her grows 30 to 40 at a time. 

[Newstead]

Those are fascinating! I have one tiny fungia growing on a LR branch that I bought with zoas on it. The structure does look very similar. Mine is about 1/4 inch in diameter. 

 

[jcrisman2009]

I'm new here...but....They do look like a type of coral....They are cute little thingys though!

[15galreefSD]

thanks for all the responses, I'll follow up in a few weeks and let you all know how they're doing! 

 

 

[jcrisman2009]

Just now, 15galreefSD said:

thanks for all the responses, I'll follow up in a few weeks and let you all know how they're doing! 

 

 

Yes! please do keep us updated! It's got my interest piqued!