What the... ? The feather duster shrunk!

[smidoid]

I got this pretty common "feather duster" nothing special some time ago and over the last few weeks it refused to come out and to be honest, everyone but me thought it was dead.

Amazingly, after what seems like weeks, it's back but the head is only a 1/4 of the original size.

Two quick (not necessarily easy) questions:

1) Why does this happen?
2) What should/can/must I do to prevent it?

I have other, smaller, filter feeders in the tank and all of them - including a orange tunicate are apparently doing well.

[Ninong]

I guess by "head," you mean the feeding tentacles radiating from the head?

If they are much smaller than they were originally, it probably means that it lost it's feeding tentacles (radioles) and they are now growing back.

Don't forget that these animals are suspension feeders. They feed constantly on whatever goodies drift their way that suit their particular requirements: phytoplankton, bacterioplankton, dissolved organics, particulates, etc.

[zhenya]

Hi Marc,

Sorry you having problems with your Sabellastarte spp., which is quite common problem that I had read about on and off on the forums in various threads. I think the common answer in most of them was that this worms are most likely to starve in the aquarium because of the lack of aproppriate food for them.
Here's an old article for you to read and ponder... FWIW, this worms often shed their crowns but no one seems to really know why, and then they regrow it back again.
Anyways, here's that linky..
Aquarium Invertebrates
And another The Worms Crawl In… by Ronald L. Shimek, Ph.D. - Reefkeeping.com

[smidoid]

I guess food is the issue then... umm... how to fix that one. I didn't see any sign that the "head" had been dumped, I just thought it had gone back in. I had read of this before - but always assumed that you'd see the radioles (?) foating about the place.

I strikes me that the poor "chap" is in an area of limited flow (at the far end of the tank in the "shadow" of a large piece of LR). Moving it might prove difficult though if he's well stuck. Suggestions for relocation are gratefully received! Seriously!

Thanks gents, I'll check those links out. Never hurts to read up.

[Ninong]

You don't want to put it in an area of strong flow, just gentle flow. As far as the food angle is concerned, that's a tough one to answer. A mature reef tank with a nice deep sand bed should provide a hospitable environment. Adding a small amount of live phytoplankton daily would certainly help. Unfortunately, you probably can't find that where you live. You could always grow your own but that's a major hassle.

[zhenya]

You don't want to put it in an area of strong flow, just gentle flow. As far as the food angle is concerned, that's a tough one to answer. A mature reef tank with a nice deep sand bed should provide a hospitable environment. Adding a small amount of live phytoplankton daily would certainly help. Unfortunately, you probably can't find that where you live. You could always grow your own but that's a major hassle.

I totally agree with Ninong about the flow...when I kept one in the early days it would always withdraw when the power head would go on and stronger flow hit it. I think gentler and laminar flow would be the best option.