What is this stick-looking thing on my sand bed?

[markkazdad]

It's there one day, then not another. Seems to be getting longer. Never really moves. At first I thought it was just a piece of rock or crushed coral that became visible when the sand was blown away from it, but now I'm not so sure. It's about 1-2 mm diameter, and about 2 cm long. Second picture with a small hermit crab for scale.

 

[ritter6788]

Just looks like a dead coral to me.

 

[Tomoko Schum]

It's rather streight for a tube worm or a vermetid worm. Are you sure it's growing?

 

[markkazdad]

No, I'm not sure. Now that I have a baseline photograph, I'll report back changes.

 

[markkazdad]

Changes

Last night at 9pm. It is moved, and bent, almost broken.

Today at 8am. Moved again, straight, and now there are two!

And my wife found this... aiptasia?

 

[WesW]

That looks like aptasia to me. Does the stick look uniform at both ends or are there little bits of sand and shell sticking to one end? My guess is the stick is a home for some kind of worm.

 

[markkazdad]

Uniform. Slightly tapered. If they don't disappear, I'll try to fish one out later and investigate further. I'm afraid it will crumble when I try to pick it up. But it looks like I have a spare.

 

[shred5]

You sure its not moving from the current or the crabs moving it.

In the first pic it almost looks like a old urchin spine.. But the broken pic sure makes it look like a old tube worm shell...

 

[markkazdad]

You sure its not moving from the current or the crabs moving it.

In the first pic it almost looks like a old urchin spine.. But the broken pic sure makes it look like a old tube worm shell...

It is in a pretty low flow area, I think. This is in an Aqueon Evolve 2, and it is pretty much right below the pump outlet. The outlet is pointed across the top to provide some surface agitation and the flow goes around the opposite corner and then down and around the large rock that is somewhat shadowing this area (flow-wise). For a visual, these stick things are pretty much below the damsel in the first photo in this thread: https://www.reef2reef.com/forums/north-alabama-reef-club/96707-markkazdads-aqueon-evolve-2-a.html

It's possible one of the little hermit crabs is moving them, but if I remember correctly, I was seeing these before adding anything to the tank except sand and live rock (which does have a few mini brittle stars, though I never see them out). I did add a bristleworm to this tank at the same time as the crabs, but I don't ever see it either.

I don't think they're bothering anything except my curiosity.

 

[Downbeach]

A chaetopterid or spionid worm tube would be my guess too.

 

[Tomoko Schum]

I second the chaetopterid worm. Take a look at this.

I have some of those in my sand bed as well. When I disturb the sand bed, I end up enearthening these tubes. Yours does not look alive to me, though. It might have been stuck to the bottom of the rock and fell out when you put the rock into your tank.

 

[OurReef]

Question?

Does it appear smooth and have a brown grey color to it?

It looks like the tube my little feather dusters make.

 

[markkazdad]

Question?

Does it appear smooth and have a brown grey color to it?

It looks like the tube my little feather dusters make.

Yes. They are just a shade darker than the sand and smoother, though I could believe they might be made of fine particles of sand glued together by secretions. I have only seen them laying horizontally on the sand. The worm home makes sense. Time will tell if I ever see them peeking out.

 

[OurReef]

I'll get a pic if mine here in a bit

 

[OurReef]

Here ya go best the iPhone can offer