Researchers from the University of Pennsylvania and the University of California, Santa Barbara, have now shown how giant clams use iridescent structures to thrive, operating as exceedingly efficient, living greenhouses that grow symbiotic algae as a source of food. This understanding could have implications for alternative energy research, paving the way for new types of solar panels or bioreactors. Here, we see the structure of the algal pillars (brown) within the clams. Sunlight at the equator is too intense for their algae to be efficient; these pillars are arranged vertically, so the algae do not receive the full brunt of that intensity. A layer of iridocytes (blue) on top of the pillars scatter many wavelengths of light in a cone-like distribution pointing deeper into the clam. Red and blue wavelengths, the most useful to the algae, spread the widest, impacting the sides of the pillars in which the single-celled plants are stacked.