Is it a starfish stuck in my live rock

[melysa]

I have these black and white tentacles about 1/4 in long, maybe longer. They extend out of my live rock. There are two groups of four or five tentacles, most likely more than that in the gravel. I have a brittle starfish in the tank that is mobile and the legs on her look the same as the ones on my live rock. Also the ones on the rock I can't actually see if they join together and they never move from their location. I think they are worms of some sort, or maybe an anemone. So what is it? A starfish that got stuck in the live rock? Some kind of worm? Or anenome?
One more thing...The brindle starfish I have was a hitchiker and I just discovered it last night. By the way I have had this tank set up for 5 months, The last piece of rock I introduced to the tank was in Feb. So, my question was, everything I have read up on has said they sift through the sand. All I have in my tank is gravel. Should I get live sand to put in the tank? And if so should I remove my gravel. I don't really want to cause Im sure there are alot of things living in the grave, seeing as how I just discovered my starfish.
Oh one more thing...The bristle worms. Will they harm my starfish, turnicates, tube worms, clams, polyps, or anything else in my tank? I don't really want them in there. I'm going to do the trap, make my own. Is there any fish, or invertabre that will hunt them down and eat them? And if so how harmful are they to the rest of my tank?

Sorry for the super lengthy questionair, I tend to ramble 8O

Thanks, Melysa

 

[Anonymous]

I can answer two of your questions I think. The legs coming out from the rock likely as not belong to a species of Brittle Star. Like star fish, only spindly. It's unlikely to emerge from the rock (certainly during daylight), but will cast its arms around looking for scraps of food.

The bristle worms are useful detritivores (i.e. you should think of them as being part of your clean up crew) and are unlikely to eat any of your livestock if it's healthy (usually if you see them feeding off something, it's already dying). But lots might indicate that you are overfeeding or have another nutrient issue.

 

[melysa]

So they are starfish? wierd.

 

[Anonymous]

I think so, based on the description. Only way to be sure would be a photo. You're welcome to post one and I'll have another look if you like.

 

[Anonymous]

Google 'Amphiuridae' and see if they don't look like what you are seeing. This genus lives in both soft sediment and rock areas and waves its arms in the current to capture food particles.

 

[melysa]

Those tentacles are Amphiuridae. I looked at the images and it's eactly what I thought. So that brittle star is that I found under the gravel, up against the glass is probably the same type. So the gravel is probably fine with her.