Tridacna Crocea on the left and center, and right is Tridacna Derasa.
If you turn the pumps off to make the surface still, get on a ladder, and look straight down, these clams look amazing. They look very different, much more colorful when you look downwards at them and not through glass sideways. This photo was taken from the side, however.
You can still see much of their beauty.
Click the photo twice to make it larger, the site resizes very large photos but lets you view the largest if you click it a couple times...
Hope you enjoy the photo, these are a wonderful addition to a reef tank!