What is this alien creature #2

[Teresa]

So I saw this thing on my zoas tonight. Looked like it might have been eating them but I couldn't tell for sure. It definitely has a mouth and its "feelers" were moving from my zoas to its mouth. I've misplaced my tweezers so there was no way to get him out tonight. Anyone know what it is?

By the way, I am treating the zoas for pox. At least that's what all the white spots look like to me.

And a PS - do bristle worms eat zoas?

Sorry for so many zoa questions, but they seem to be melting and disappearing from my tank lately. Any help would be appreciated.

[mooric]

Looks like it could be Aiptasia. At first I thought it was just a bristle worm till I viewed it full size.There is definately a bristle worm in the foreground of the first photo though.

[Teresa]

I put the first picture there to show the bristle worm on my zoas. Iv'e never seen one appear to be eating the zoas before and I didn't know if some bristle worms might do that.

The second and third pictures are of the "creature." I have aiptasia in my tank, but this thing actually moves around. It went from one zoa to the next.

[Robb in Austin]

Are there zoa eating nudis? Looking at that picture full size reveals what appears to be a tail coming out the bottom almost directly under the head.

Check on wet web media; but only when you have some time to read through the site. It can be difficult to follow at times.

Here is a link to the zoa predator FAQ part one:

http://www.wetwebmed...hidhlthfaqs.htm

About a third the way down on that page there is a mention of zoa eating nudis. Read up.

[mikedelgado]

I dont think bristle worms are harmfull to corals. I believe they are just a benificial scavenger.If that anenome looking guy in the second pic moves from zoa colony to colony I would remove it. I tried to focus in on the 1st pic , it appears to me there could be a nudi pokin out from behind a polyp but i'm not positive. Inspect all of your zoos closely as the nudis take on the color of whatever zoo they are munchin on.You may want to try a dip for the pox and see if any harmful creatures fall off. If you have nudis they are easily handled by a wrasse.

[JamesL]

The second picture actually looks like a clove polyp sticking out from behind the zoas.

[Derek]

That is weird! Looks like a bristle worm to me.

[Timfish]

The second picture actually looks like a clove polyp sticking out from behind the zoas.

That's what it looks like to me also. If it's moving around though my second guess is a small cucumber or medusa worm.

[JamesL]

I was referring to the thing circled in pic 2.

[Teresa]

Ok - I found my tweezers and used them to pluck him out from among the zoas. He is clearly not an anenome, clove polyp, or bristle worm. The picture below is the best I could get. He is surrounding a small pellet of found and is basically see through. Looks like he has an eye? Is this a nudi? Is he bad for my tank?

[Teresa]

sorry supposed to say pellet of food (not found)

[Timfish]

Considering what looks like pinnated tenticles in the 2nd photo from your first post I'm thinking a small cucumber of some kind. If they are tenticles it's not a nudibranch but if those are the gills of a nudibranch it would only be a threat to it's host species which presumably is the zoas.

[stoneroller]

Doesn't look nudi to me. Take a red or blue light and inspect all of your colonies at night with a magnifying glass or 2X readers. I don't see signs of zoapox just maybe some detritus. Keep em clean with a baster or powerhead.

What's up with the rubberbands?

PS. What kind of zoas do you have that are melting? Where are they from?

[GKarshens]

It looks like a Nudibranch to me if the tentacle looking things in the socnd pic are coming from the same creature in your follow up pic. There are Zoa eating Nudibranchs.

[Dena]

I have to agree with Gabriel. I bought a zoa colony recently from an LFS and it had one of the aracnid things that eat zoas AND a nudi on it. I have never seen one before, but I knew exactly what it was when I saw it moving around on the colony. Definitely glad I saw this and dipped the sucker before putting it in my tank.

[Teresa]

yeah - i guess i learned my lesson about preforming dips prior to just placing a rock or coral in my tank. I could use more info on the dip process though. I'm assuming its a freshwater dip? For how long?

[MSHROOM13]

Medusa worm (a type of cucumber actually). Harmless detritus eater.

[stoneroller]

not a nudi. Regardless it's out of the tank now.

I dip all of my zoas using RO water and a iodine-based coral dip or Lugol's. It doesn't take long for nudis to start falling off, zoa spiders can dig in a little and it may take a little longer. Most of the other critters fall off quickly usually in less than a minute or two. Look for sundial snails while you are at; they are cute but deadly - see below. The most important step is to inspect each polyp for nudi egg cases which are spiral-shaped. Pick them off with tweezers. Again I use a magnifying glass or 2X readers to get a close look. It's worth the hassle to pre-treat and inspect thoroughly regardless of where the frag or colony is from. Truth is I pick off nearly everything (algae, sponge, detritus, clams, black stinky crap, etc.) but the zoas, if it's a nasty rock I may peel them off that and remount.