This crawled out of my live rock

[Nancy]

Any idea what this is? I'd think a nudibranch, except that it has a kind of shell on the front. I'm giving you all the first chance at IDing this critter. My concern is also how large it will get.

Nancy

 

[Animal Mother]

Stomatella snail most likely. Harmless. They reproduce well and Kalypso found them mighty tasty as a youngster.

 

[Thales]

+1 on Stomatella. Don't get bigger than and inch and are great for algae.

 

[Nancy]

Thanks to both of you! I'm just as glad it's a snail, and come to think of it, it was eating algae when I spotted it!

It's already about an inch, so maybe it's full grown.

Doesn't show up in the photo, but it's shell is a beautiful irridescent pearl, slighly purple.

Nancy