How are clams graded?

[estrange]

I see different grades for clams all the time but I don't see specific patterns pertaining to the grade.

 

[jmaneyapanda]

dont be swayed by retailer "grading". find one you like, thats whats important. business put "grades" on clams to justify differences in prices. I dont know if there are any standards (such as with japanese koi), but such standards are arbitrarily chosen and are no indication of animal health and suitability.