Help ID please, sand sifting clam???

[lakedawgs]

HI,
Been out of the hobby for a couple of years and just setup a 12 Aquapod. Just purchased about 18# of very nice LR from an individual that also gave me what he called a 'sand sifting clam'. Is this something I want to keep in such a small tank. For the last couple of days it has not done much. Slightly opened enough to stick out its vent tube, 1/2 buried itself in the sand and thats about it. My sand bed is 1" thick or less.
Here is a pic,
THANKS,
Lakedawgs

 

[blackcloudmedia]

Looks like a quahog clam or like species to me. Id take it out unless theres a lot of algae/nutrients in the system to filter. In my experience clams like this starve to death in reef tanks then die...then nuke the tank unless theres something to eat it. The shell will open when it dies usually. Just an FYI these things grow rampant in the St Johns River and intracostal waterway here in Fl which has PLENTY of nutrients to feed off of.