Colonial Hydroids?

[DP Reef]

I found these on one of my recently added live rock.

Aiptasi, Featherdusters, or Colonial hydroids?

They all seem to have little things coming off at the end of the tub and i dont see any retraction when i point a light at it.

If they are colonial, i guess I should take them out immediaty. Been in the tank a few days,could they have spread?

 

[Mat1018]

From the picture all I see just looks like purple coraline but if you can describe when you have a little better I might be able to help. With feather dusters if you put something in the water near them they will suck back into there tube for safety but if its hydroids there a form of a jellyfish and if you look really close on your tanks glass you should see small white specs about the size of a tip of a ball point pen or smaller looks like a micro starfish but it's not. If you can describe what you see better or point it out in the picture I might be able to help

 

[ItzJustinN]

vermetid snails.

 

[DP Reef]

Brown stalk, a bit rigid when pushed with my net. On the other hand, I found that their white thing tentacles retract when I nudged it with the net.

I got this rock becuase of the deep dark purple coraline, but now may just remove it to be safe.

If you download the pictures in zoom in, you will see 2 colonies of these items. Both "NW" of the green spot of algea.

 

[Anemone]

Yes, hydroids. You don;t have to toss the rock. Use a flatbladed screwdriver to "dig" under the base of the colony. Live rock is generally pretty soft. You'll have a divot spot devoid of the coralline, but it will grow back and cover the spot so you won't be able to tell it from the rest of the rock.

Kevin

 

[Anemone]

Double post.

Kevin

 

[Mat1018]

So it's not a aiptasia because if you get close to them they will suck back into the rock. From what I looked up it might be the second form of hydroids but I still can't tell. And can't really look it up good since I'm using my phone to research it but just google hydroids and see if you can find a site that shows pictures or tells more about them. Because I do have the hydroids in my tank but the first form that looks like small star fish from what I saw online is they won't really hurt anything but sps corals seahorses and that after they run out of a food source they will die off. But I'm not saying that I'm a hundred % right about what it is maybe someone else will help out.

 

[DP Reef]

I have read in a few places that tips of these hydroids will be released to spawn iand that in some instances as some have mentioned, will harm other corals.

My nervousness made me just toss out the small rock which probably gave me some more surface area on my substrate (looks nicer). The only thing I am sad about is that it was such a nice dark purple coraline. I have coraline on some other rocks but are much ligther. Hopefully that is just bleaching/whiting during the cycle and the other coral will also get this dark purple.

Thanks all for the help!

 

[SushiGirl]

What Kevin said.