various critters

[Dargason]

Hi! I'm fairly new to reefkeeping, but I've had my little 20 gallon tank running for a little over 2 months now. Last night I bought a couple of corals that I learned were hardy and put them in the tank. I purchased a mushroom coral and a green star polyps rock.

I was quite pleased to see that the corals quickly adapted to their new environment and seem to be doing fine. When observing the GSP, however, I noticed a number of other critters that were something else. Since I'm new to this, I'd like your help in identification and in learning how to care for (or eradicate, if needed) my new tank inhabitants.

First, there is a long tube sticking up from the rock. I saw this when I picked out the coral, and I assume it is a fanworm that has lost its fan. It is now putting out a long web-like strand that I assume is how it is eating. It seems quite active, and I'm hoping to see a nice fan in a few weeks. However, is there something else this could be?

Second, when placing the rock I looked at the underside. There is a jet-black flat "worm" about 1/2 inch long and almost as wide. It has 2 antennae sticking out of the head. It seems to avoid light... I'm guessing this is a slug, flatworm or nudibranch of some sort. Can anyone help me determine a positive ID? Is it a friend or foe?

In a related vein, there are also several (6 or so) much smaller flatworm type things. These things are about 1-2 mm long, green on one side, and green/brown on the other side. They have a little red dot at the tail/head. Given the number of them, I suspect these are a pest, but are they really? Should I try to get rid of them? This may be moot, however, since I don't think they survived the transport anyway.

I also found 4 anemones. These are quite small, about 0.25-0.5 inches across, with a pretty dark-green color. I originally thought they might be small bubble-tipped anemones, but I went back to the fish store today and he said he thought they were flower anemones. Can anyone tell me about these? Are they hardy? Do they need to be fed?

There is also a small white spherical thing... I'm not sure if it's alive though and the GSP is growing over it.

Any help you all can provide this beginner will be much appreciated! I'm also open to advice on caring for the GSP and the mushroom coral!

 

[Dargason]

Oh yes, I nearly forgot. I'm pretty sure I saw a bristleworm poke his head from a hole in the rock. He was very tiny, though, so I can't be sure. He had a pink/orange upper body and I think the later part was a different color... maybe a bluish grey. It was hard to tell since he was so small (diameter of about 0.5 mm) and never came all the way out of the rock.

I don't plan to worry about him unless he multiplies and/or does damage. Do you agree?

 

[MedicineMan1]

I think I can be of some help here:
<OL TYPE=1>
<LI>Sounds like what I believe is referred to as a vermitid snail. It's a stationary snail and your are correct in that that is how it eats. They are good things to have.
<LI>You're pretty close on this one. I suspect it is what is referred to as Stomatella snail. Does it seem to have a too small shell? Again, these are good to have for clean up purposes.
<LI>These may be the dreaded Aceol flat worms. The only harm they really seem to cause is just the sheer numbers at the high end of their population cycle (they go through population explosions and implosions and I'm not sure anyone other than God knows why at this point). I wouldn't be too concerned as they are kinda pretty when hundreds are gathered together side by side making a little sheet.

P.S. Do NOT refer to them as "planaria", a simple freshwater flat worm.
<LI>These anemones may be of the Anemonia genus. They're not too big, are tougher than nails and can multiply quite readily. The only sure-fire way I've heard of eliminating them is to pry them out by their foot with a pen knife. If you don't get all of it, the remainder will grow back. Definitely a pest!
<LI>The small white spherical thing, I'd guess, is a sponge of some sort. What texture does it have? Is it smooth, fuzzy, rough or other texture? That would help with ID.
<LI>Finally, bristleworms are not to be worried about. They crawl through the pores in your live rock and clear out the detritus. And, from your description, it sounds like one!
</OL>
Happy Reefing!

DISCLAIMER: None of the information above is guaranteed correct; it is all my "best guess" based on your descriptions.

 

[Dargason]

Thanks for the help! I think the black wormy-thing is probably a stomatella snail, as you said. There wasn't a shell exactly, but I noticed there was sort of bulge in the middle of his body that might have been a spot where his skin is harder/less flexible. He kinda looked like a little black ravioli with antennae.

Do you think I should start trying to eliminate the anemones? What sort of damage to they do? They are actually rather attractive so unless they are likely to cause me big problems later on I think I'll keep them a while.

The white thing looks very porous, so a sponge would be a good guess. I think there are actually a couple of them. I wish I could get a decent picture of it for you.

So the tubeworm thing won't grow a fan? I thought it would so I'm glad I asked. Now I won't worry if it doesn't grow one.

Thanks again for the help!

 

[MedicineMan1]

I wouldn't suggest to do anything with the anemone until you get a positive ID. Search the FAQ here and check other sources for ID.

 

[wla20]

I think what most people refer to as a flower anenome is an Actinia species (possibly equina??) I don't have any experience with them in reef tanks but I have kept beadlet anenomes from the same genus in coldwater tanks and had them successfully reproduce quite a lot. However I wouldn't say this was a problem because, they took quite a while to reproduce and were hence controllable and were very attractive anyway. Some of this will probably apply to the tropical versions.

HTH

Wayne

 

[Dargason]

Wow, you guys are full of good information.

Well, my web and photography skills are pretty bad, so I apologize in advance, but I put up some photos of my tank and some of these unknown inhabitants on my web site. It might load slowly... be warned!
http://members.home.com/mikeries1

I'm still curious about the anenomes. I don't think they look much like the one in the faq, although the description is quite similar to what I have.