After recently up grading my lighting to 2x250 MH ( 75 g tank), I am looking first for information on the captive keeping of, recommendation of what kind and a online retailer with a good rep for purchase.
Derasa or Squamosa are good starter clams..I would also recommend reading the new clam book, "Giant Clams in the Sea and the Aquarium", by James Fatherree **before** you purchase your first clam.