What the heck is this?

[Funwithreefer]

My blue dot likes to dig out his little caves under the live rock. Was checking out his latest one and saw this thing sitting on the side. At first I thought it was a penny but then I noticed the spiraling on it which looks more like a shell. But it seems to be thin like a penny. Any ideas what the heck this is? Also included a pic of the blue dot for fun.

 

[Seabiscuit]

Looks like the spiraling on a snail shell. My cave fish move pieces of shell and rock around the tank daily.

 

[Brad Waddell Wrath's Reef]

It looks to be the flap for a snail shell.

 

[Jmasonreef]

Dead snail for sure.

 

[Maritimer]

That's the operculum (sort of a back door - it seals the opening of the shell when the snail pulls in) of a snail - probably something like a turbo.

~B.

 

[JGT]

My blue dot likes to dig out his little caves under the live rock. Was checking out his latest one and saw this thing sitting on the side. At first I thought it was a penny but then I noticed the spiraling on it which looks more like a shell. But it seems to be thin like a penny. Any ideas what the heck this is? Also included a pic of the blue dot for fun.

Snail trap door. Seals off snail from intruders. One of your bigger ones musta perished.

 

[Jeffcb]

artifact