Uh...what are these?

[redhawk45]

After 2 years and stupidly thinking they were algae and almost scrubbed them off the rock permanently a few weeks ago, I took a closer look - real close with magnifier - and noticed these two kinds of critters. One looks to be a polyp of some kind and the other looks to be a fan worm - both are green!

 

Any ideas as to what they are? Took a couple good photos - used my macro setting on camera for the first time.

[Euphyllia]

That rock looks pretty nasty...

[redhawk45]

That rock looks pretty nasty...

 

Edit: ok, the feathery stuff does look like aiptasia...but how do I rid of it without killing the clove polyps and declining the amount of LR I have...which isn't much to begin with? I used to have a peppermint shrimp - twice - but they weren't doing much of anything. Yea, the rock is isolated.

[matty0206]

Those look like hydroids to me.

[joshnanoreef]

Those look like hydroids to me.

 

+1 those are NOT aptasia. Keep them, they won't spread quickly.

[Builder Anthony]

i like them they are fine to me i have some for about a year now

[redhawk45]

Hmm...well, true...if it was aiptasia, it would have destroyed the clove polyps or whatever those polyps are. These are living together with each other. They grew up side-by-side with each other. And they are isolated from any other rock work and corals. If you see my link to my tank, it's the fist size rock in the foreground (gotta post a newer photo once the inside sides of tank is clean again tomorrow).

[sublunary]

Definitely colonial hydroids.

 

I have mixed feelings on them. I once had to get rid of a rock because they spread so fast, took over the whole thing and started killing stuff I wanted. But I have about a dozen on a zoa frag now that aren't spreading or bothering anything - just being kind of ugly.

[joshnanoreef]

They haven't spread in my tank. For some reason they commonly grow with clove polyps.

[Whys]

+1 colonial hydroids. They're filter feeders, have stingers, and can be a nasty problem if they start spreading. If they stay put, then count your blessings, because eradication can be difficult.

 

They actually have a fascinating life cycle and the adult medusa look like tiny jelly fish. I've been battling them in my kreisel, but options are few and can be drastic. More of a problem for people breeding fry with baby brine shrimp.

 

hydroids in general can take on a lot of different appearances and often do look more like aptasia.

 

 

If you look at your "algae" (I fell for it too) with a microscope, it might look something like this.

 

Video:

 

The medusa are really quite beautiful. Wish they were on my side.

 

Video:

[redhawk45]

How large do these mini jellies get? I don't need them hurting my fish, either...see, I didn't say other coral because I'm sure like most jellyfish they move with the current and would get sucked up into the filter part of my tank. My other question...could they actually just stay hydroids and not turn jelly?

 

Also, my colony doesn't really twitch around at all...they just stay there, waving their arms in the water like feather dusters.

[joshnanoreef]

You're over thinking it. You can barely see the "mini jellies." Mine rarely produce medusas anyway. If you like them, keep them. They probably won't do any harm. If you rather play it safe, then remove them.

[Whys]

The adult medusa in the video is about 2mm in diameter. Also, I can't see the colony "twitch" without the microscope. To the naked eye, it really does look just like algae.

 

 

Many colonial hydroid polyps are larger and I assume the same is true for the medusa. Basically, hydroids can vary a great deal in scale.

 

In my own experience, they need a lot of food to be successful, spread, and reproduce, but very little food to simply remain in place. They can even go dormant, for long durations, when food isn't available. Obviously, the more food it has, the more likely you'll see medusa, but I've never seen them in my display tank, just my kreisel. Tho I suspect they exist in both, they've just never shown themselves in the display because I don't dump baby brine shrimp in there on a continuous basis.

[matt frizz]

Listen, these colonial hydroids suck and spread fast. I have them in my tank. They eventually kill zoanthid from pissing them off so much. 12 on one rock will be many many more in time. Luckily my Sunset monti can just encrust over them but other corals can't.

 

I'd say remove any rock with them on it and replace it.

[redhawk45]

I already figured a good way to get rid of them if the time comes. Get some epoxy putty and put over it to smother it all. I was trying to get a frag to stick on top of that rock once, had a whole glob of the epoxy on there, but the frag just wouldn't stick. After that, I pulled the epoxy off and it was like a clean slate...no coralline, no algae, just bare LR. I just hate to kill the clove polyps...never had them before.

[Whys]

Peroxide..?

 

No, I did not just say that!

 

Not a fan, but curious to see how it might work against the hydroids. Might allow you to keep your clove. Might.

[Dendroguy]

fan worms or like everyone else, hydroids , I have a rock with hundreds of worms that look like that, If they have an x in the middle they are worms

[redhawk45]

I see where you see the X.

 

fan worms or like everyone else, hydroids , I have a rock with hundreds of worms that look like that, If they have an x in the middle they are worms

 

 

I'll also say that when I accidentally was scrubbing those few weeks ago, the outside tubes (if you call them that) are tough...reason why I stopped scrubbing...lol. It wasn't getting them off.