It’s always a pleasure to see one of these beauties on the reef. Giant clams are large, colorful and, surprisingly, they are part animal and part “plant”. That’s because giant clams, like corals, have plant-like cells (zooxanthellae) in their tissues that produce free food for the clams. When a clam opens its shell and spreads out its pretty mantle, it exposes these solar panels of zooxanthellae to the sun to make food, like a plant unfolding its leaves.