unusual worm

[aztbs]

I have these very strange worms living in the sand bed. They are shy to light and only come out in the dark, and they can only be found in a small group in one area of the tank. I would love to know more about what they are.

I apologize for the clarity of the photos, the only way I can see them is to shoot at an angle through 1/2in glass. This is the best I can do.

This is the only shot where the body shows enough to see the stripes. They have a very distinct brown and white stripe. The mouth area camouflages very well with the sand and they have thick clear tentacles that stick out radially. You can see the one on the bottom of the mouth in this pic if you look carefully.

You can make out the tentacles in this pic

Here's a little group of 3:

They just poke their heads out at night and fully expand the tentacles to catch food. In the day, they are well buried. I thought they were some kind of polyp until I saw one stick its mouth in to a cerith shell and eat the snail meat. When I shined the light on it, it dropped the snail and retracted quickly. They do not move from their location at all.

Any ideas on these? I have tried to pull one out but they retract deep in to the sand. I would make a giant mess trying to get one.

 

[KarlBob]

They could be medusa worms. Here are a few pictures of them at Wet Web Media. To me, yours looks like the one about 2/3 of the way down the page, with the heading -Worm ID-.

 

[aztbs]

I know the pictures are not great, but it is quite different from the medusa worm. The tentacles are clear, thick and blunt tipped, it kind of reminds me of the little cup coral mushrooms.
But the body has got distinct brown stripes, is long and looks to have a semi hard surface. I have colored them yellow here so you can possibly make them out in the pics better:

 

[aztbs]

By cup corals, I mean ones like this:
http://www.melevsreef.com/id/cup_coral.html

They are nowhere near the same animal, but the tentacles have a very similar look.

I should add that the whole head is about the size of a pencil eraser, if that big. They may be the size of a quarter from tip to tip on the tentacles.

 

[Sugar Magnolia]

They could be little sand anemonies.

 

[charlesr1958]

They are most likely a Nynanthea anemone, for photos and more information, please see the anemone section of my hitch hiker pages.

A Hitch Hikers Guide to the Reefs

Chuck

 

[aztbs]

That could be it, the ribbed/striped body is a major characteristic. I am going to get one out to take close ups and see what the back end looks like.

Thanks Chuck, your website is fabulous and I have used it quite a bit for ID's. The link for Nynanthea Anemone is no longer valid, I was hoping for a larger image.

I found this link:
http://tolweb.org/images/Nynantheae/17673

None of them look quite right, but close.