mystery invert ID

[pyro]

I've had this thing since I got my live rock setup, and I've always thought it looked funny. The other day when I was pulling my hermits apart, I saw it jut in and "close". I'm thinking it is sometype of invert, maybe a crab of some sort. If you look in the opening, you can see 2 "legs".
Any help would be great, Thanks!

 

[moray345]

Oyster:yes:

 

[pyro]

Should I feed it?

 

[viper_930]

Not really necessary. It's a filter feeder, and would eat the phytoplankton and other small organisms floating in the water column.

 

[007]

Turkey-Wing clam . . . .

 

[tuningvis]

spiny oyster

 

[cathbad]

It is a turkey wing, Arca arca.

 

[jacknjill]

some kind of oyster i think

 

[bang guy]

Turkey Wing Clam

 

[tuningvis]

i thought i'd guess since everyone else was