Pictures don't do giant clams justice at all. Seen in person, they glow like something from outer space--like galaxies or nebulae or some kind of sci-fi light creature.
> This may also explain the mantle colors of giant clams. The idea is that the vibrant colors of giant clams are not due to optical differences in the tissue, but rather differences in the distribution or abundance of symbionts relative to iridocytes in each individual.