Mystery tentacle gathering up substrate?

[mattdean]

I have a rock with some zoanthids on it. I have notice gravel pile up on one section of the rock. I thought it was my closed loop return doing it. I shook the rock off and one or two days later, the gravel is there again.

This evening I witnessed a long, very thin, almost clear - milky white maybe - string with gravel attached to it being drawn up to the rock. Then, once it was up on the rock, it floated in the water for a few seconds.

It reminded me of my Serpent Star's arms coming out of the rock, but considerably smaller and thinner. Also, seems to be more than one. Any ideas?

Sorry, best photo I could get

 

[Kurt_Nelson]

Looks like some type of worm building a nest. Seems like I remember reading somewhere about a type of worm that incorporates sand into a casing that protects it? Does that ring a bell to anyone else...? (Nice zoanthids, by the way!)

 

[thincat]

They are called spionid worms and you can find them here:Xtalreef

 

[mattdean]

We have a winner! Yes, Spinoid worms for sure. Just gald they are good and not bad

Cheers

 

[thincat]

Keep your eye's on your tank. All sort of surprises to come.

 

[mattdean]

I know. I love that part about saltwater. With freshwater, the only things that showed up in the tank, that i didn't put in, were various forms of algae!

Cheers

 

[BabyDee17]

Is having alot of spinoids a bad thing? I have at least 3 big rocks filled with them... Is there something I should do?