What is this possible anemone?

[kmr4au]

This tank has been established for almost two years and this popped out about a month ago. It looks like some kind of anemone. The arms look like red christmas trees.

 

[Anonymous]

It's really hard to tell what that is, but it almost looks like the feeding crown of a filter feeding sea cucumber. I highly doubt you've been able to keep one for two years without even knowing about it or seeing it though. Have you recently added any live rock? Does this thing retract into the rock? Is it hard or soft? What kind of scale are we looking at?

My second guess is some type of foramniferan, but please keep in mind these are really just guesses...

 

[wade1]

Thats foraminiferans....

http://www.reefs.org/hhfaq/pages/main_p ... _rock3.htm

There are a bunch of little red/beige pointy things in many of the caves
of my rock and are no more than 3mm in size.

These are probably foraminiferans. These little creatures are basically shelled protozoans, one celled organisms (Subphylum: Sarcodina - the amoebas). They form shells primarily composed of calcareous material, with siliceous material from sponges, or other organic material. They are mostly sessile (non-moving), but can move with the use of temporary structure called a "pseudopodia". This little "arm" reaches out and pulls the rest of the critter along. In any event, they are harmless bacterial/detrital consumers. There are many different shell shapes and colors that these guys may have, see more forams

Wade

 

[kmr4au]

pulling things into the mouth at the center. That description doesn't fit this. Though there are foraminiferans in the tank.

 

[wade1]

Now I think I understand. Its a spaghetti worm (you see the clear tentacle like thing down right in the image?) or other rock boring, net type worm. What its done is dragged those foraminiferans to its hole and left them there. Those are nice to have as they clean up detritus.

Wade

 

[John_Brandt]

I'm putting all of my chips on sessile sea cucumber. There does appear to be a terebellid worm (spaghetti) tendril in the photo as well.

The body of the cucumber is inside the rock with the feeding tentacles exposed. As you have observed, it actively pulls these tentacles into it's central mouth to remove particles that have adhered to them.