How to tell good from a bad clam

[kouma]

Hi.
My LFS brought in a number of clams and I put a deposit on two really nice ones that have a combination of brown and blue colors..Not sure the kind, but I will take pictures later (after I put them in my tank). Now, how can I tell a good from a bad clam. Both clams I reserved are attached to pieces of rock, so I guess the foot is still there.
Any help is appreciate,

 

[nycbob]

the most basic tests r putting ur hands over the clams to see if the mantles retract or react. second, observe the mantle for any bleaching or tear. third if possible, make sure there isnt any physical damage on the shell. these r just some basic signs of health. what kind of lighting do u hv?

 

[pbnj]

I'm by no means a clam expert, but when I purchased my 2" Maxima and my 6" Derasa, I just looked to make sure they were nice and open and that the mantles were fully extended and healthy looking. Make sure the shell itself is in good condition too.

 

[candycane]

I figured out a weird way to put it a few weeks ago. Ever purchased flowers for a special occasion? I could probably say the same rules apply with picking out a clam. Nice, open, no tears, nothing (kind of) missing where it extends or opens, colorful, nice pigmentation, etc. No gaping is something that is similar. All though I still stand by gaping, in my experience, is never a sure sign of anything; you still might want to stay away from the ones that have their mouths all hanging open droopy.
If you have the chance to look under the clam and see if all the parts are intact, that is usually a big part of it right there.

 

[jackri]

The hand over the light source to see if it retracts is a good healthy sign -- and visual appearance. If something looks off -- most likely it is.