ID formation in sand

[RWLydell]

Any thoughts on what may have built this sand structure overnight? It's about 1 inch tall and 2.5 inches long. I don't think it's from any of my known tank inhabitants (clown, tang, turbo snails, trochus snails, hermits, cleaner shrimp, peppermint shrimp, bta, mushrooms, polyps). 125 gallon with 150 lbs live rock running for almost a year.

 

[oneofmany]

Hmm. Did you use any live rock? You might have some sort of hitchhiker lurking among them. If you haven't already you might want to start checking the tank at night with a flashlight.

 

[Ron Reefman]

Have you tried moving the sand to see what's inside? I don't have any good suggestions as to what it might be based on a pile of sand. If I were you I'd want to know.

 

[johnike]

Have you tried moving the sand to see what's inside? I don't have any good suggestions as to what it might be based on a pile of sand. If I were you I'd want to know.

This.
Tagging along...

 

[Sugar Magnolia]

Some type of hitchhiker worm? Eunice?

 

[RWLydell]

So I lifted it out and it came out in one piece. I broke it into several pieces with my fingers and found nothing inside. While I was doing this, one of my two Tiger Conches came by. So I googled Tiger Conch egg sac, and sure enough! See pics from web below. I'll put the pieces in my refugium and see what happens.

 

[joshbrookkate]

Cool!

 

[Ron Reefman]

Yeah, if you had shown me the egg case I would have said conch, They wash up on the beaches here after most any storm. Usually they are empty, but once in a while one will still have the little guys still inside.

 

[johnike]

Very cool.

 

[Sugar Magnolia]

That's pretty cool. We never stop learning in this hobby!