Please help me ID this snail/mollusk

[nicksc]

This little critter came in on the bottom side of a new zoanthid's little chunk of live rock I think. It appears to have a dark, leathery covering over a pearlescent shell that it can stretch to either cover it almost completely or expose much of it. The covering has some tentacle looking projections.

Any clue as to what it is so I can learn more?

[mbbuna]

To Reef Central

im not the best with snail ID's but i think you have a cowrie. most of them are beneficial but there are a few hundred types

ill see if i can find someone to give you a positive ID

[nicksc]

Thanks!

[skinz78]

looks exactly like the cowrie I just purchased at The Shark Reef two weeks ago so if you shop there too you got what I got. Mine dissapeared into the rockwork and I haven't seen it since. I wish it would show itself more it is really cool looking.

[nicksc]

Wow, really?

It came on a green/brown button polyp colony's live rock I believe. I bought mine a week and a half ago. My cowry can be seen every couple days. Looking at pictures of shells and general information about size (http://www.gastropods.com/Taxon_pages/Group_Cowry.html proved really useful), I think it may be a Ringed Money Cowry, Monetaria annulus annulus, due to faint goldish lines on an otherwise pearly white shell. He is probably about 25mm long.

From what little I know, some cowries may cause trouble in a reef tank. So far mine spends all day holed up in crevices or scooting aroung live rock. I don't know if he is eating the algae (and not what little amount of organisms the rocks may have in my fairly new tank), but I hope so.

If anyone has experience with these guys and can give some advice as to what I should expect and if I should pull him, please let me know.

[nicksc]

I forgot to mention - I bought mine at Blue Sierra in Issaquah.

[yiliyang]

It is a money cowrie. They are reef safe, just algae grazers. Yours looks really nice. I seen them for sale for about $5.

Enjoy it.