<a href=showthread.php?s=&postid=7751533#post7751533 target=_blank>Originally posted</a> by mbbuna
Squamosa's are found on the reef(rocks). Derasa's when they are small will most commonly be found on the reef, when they reach sexual maturity you jettison themselves to the base of the reef. most of the time the substrate there is a hard calcium cabernet.
clams will only be found in sand in a very sheltered area. sand is dynamic , blows around and moves. a clam, any clam, wouldn't last long buried in the sand