Is this thing dangerous?

[intranet]

There is a white "polyp" of sorts on the side of a piece of my live rock. It has two almost clear tentacles that come out of it, sometimes getting very long ( a few inches ) . It has green around the "polyp" but I think it is just some bubble algae.

We had a bubble / star polyps coral nearby it , today it looked very bad so we moved it, thats when we noticed the thing with the tentacles, as soon as we moved it it perked back up.

Here are some pics :

http://67.165.54.166/fish/thumbnails.php?album=13

This seems to be the clearest pic of it and one of the tentacles:

http://67.165.54.166/fish/displayimage.php?album=13&pos=0

You can click on the photo to enlarge it to get a very close view

Thanks very much for your help!

[Periclimenes]

Could u describe the tentacles please. Are they stringy, like spaghetti worms?

[intranet]

Hey , found a real pic of spaghetti worms and yeah, looks just like that. only it only has two of them and the "base" of it is white with green around it, but the tentacles look just like the ones in the picture on the right here:

http://www.coralreefnetwork.com/stender/marine/worms/worms.htm

[xxaquanutxx]

I donno... never heard of 2 tentacles only

[Periclimenes]

Do the tentacles come out from a hard tube?

[Rock Anemone]

Very hard to tell with the pictures but from the description it sounds to me like a Vermetid gastropod. Check out this thread I posted for more information: http://archive.reefcentral.com/forums/showthread.php?s=&threadid=300994

Rock Anemone:D

[intranet]

Originally posted by Rock Anemone
Very hard to tell with the pictures but from the description it sounds to me like a Vermetid gastropod. Check out this thread I posted for more information: http://archive.reefcentral.com/forums/showthread.php?s=&threadid=300994

Rock Anemone:D

Its not those, I am pretty sure, cause I do have those too! Your thread was a great help, I was wondering if a spider had invaded my tank.

[intranet]

Originally posted by Periclimenes
Do the tentacles come out from a hard tube?

looks just like a small white flower

[intranet]

Originally posted by Periclimenes
Do the tentacles come out from a hard tube?

looks just like a small white flower

If you click on picture 1 twice ( to enlarge it as large as it will go )
it shows a pretty close shot of the "base" of it

Originally posted by xxaquanutxx
I donno... never heard of 2 tentacles only

I keep looking but can't find more than two, its at an odd position in the tank, and on the bottom of a bunch of rock, but I can only see two , they are out and moving pretty often, but are sometimes quite small.

[dc]

I think they are Spinoid worms. Only 2 tentacles, and if they are on the sand, it kind of sticks to it much like a feather duster tube.

[intranet]

they are on a live rock, coming out of a flower looking white thing

[jamison]

I have also seen something very similar in my tank. I probably have 3 of them that I have seen. There are only two "tentacles". Mine seem a little thinner, and if you look very closely, they are feathered with many small tentacles branching off of the main two. All uniform and in the same direction. I do wonder what they are. As of yet, I have not seen them do much and they seem anchored in one spot without moving. Are yours feathered also? Best of luck. I'll be tagging along for any words of wisdom.

[intranet]

I can't get a close enough look to see, very interesting though, and I am going to see if I can do a bit of rockwork to move it more into the open.

I'm glad I am not the only one who has seen them anyway. They sound exactly alike, aside from I am just unsure about the feathers, the picture actually affords a better look than I am able to get in person.

[intranet]

http://www.rshimek.com/odd_critters.htm#Ctenophores

There they are... harmless.. thank goodness